THE PERFORMANCE OF DOUBLE CROSS HYBRIDS OF
SILKWORM, BOMBYX MORI L. IN CENTRAL DRY ZONE OF
KARNATAKA
SHARANYAKUMAR GOWDA, Y.K.
PALB 2288
DEPARTMENT OF SERICULTURE
UNIVERSITY OF AGRICULTURAL SCIENCES
GKVK, BANGALORE-560-065
2014
THE PERFORMANCE OF DOUBLE CROSS HYBRIDS OF
SILKWORM, BOMBYX MORI L. IN CENTRAL DRY ZONE OF
KARNATAKA
SHARANYAKUMAR GOWDA, Y.K.
PALB 2288
Thesis submitted to the
UNIVERSITY OF AGRICULTURAL SCIENCES, BANGALORE
in partial fulfillment of the requirements for the award of the Degree of
MASTER OF SCIENCE (Agriculture)
in
SERICULTURE
BANGALORE
JULY, 2014
PARENTS
SRI.KALEGOWDA
SMT. MAMATHA
BROTHERS,
MR. GURUPRASAD GOWDA, Y. K. AND
MR. NANDISH GOWDA, Y. K.
And
MY GUIDE
DEPARTMENT OF SERICULTURE
UNIVERSITY OF AGRICULTURAL SCIENCES
G.K.V.K., BANGALORE-560 065
CERTIFICATE
This is to certify that the thesis entitled “THE PERFORMANCE OF DOUBLE
CROSS HYBRIDS OF SILKWORM, BOMBYX MORI L. IN CENTRAL DRY
ZONE OF KARNATAKA” submitted by Mr. SHARANYAKUMAR GOWDA, Y. K.,
PALB 2288 for partial fulfillment of the requirements of award of the degree of
MASTER OF SCIENCE (AGRICULTURE) in SERICULTURE to the University of
Agricultural Sciences, Bangalore is a bonafide record of research work done by him
during the period of his study in this university under my guidance and supervision. The
thesis has not previously formed the basis for the award of any degree, diploma,
associateship, fellowship or other similar titles.
Bangalore
July, 2014
(D. CHANDRAPPA)
Professor and Programme Co-ordinator
KVK, Babbur Farm, Hiriyur
APPROVED BY:
Chairperson:
____________________________
(D.CHANDRAPPA)
Members:
1. ____________________________
(T.K. NARAYANASWAMY)
2. ____________________________
(CHIKKALINGAIAH)
3. ____________________________
(RAMAKRISHNA NAIKA)
4. _____________________________
(VENKATESH, M.)
ACKNOWLEDGEMENT
With ever regardful memories………
First and foremost, I would like to make a prayer of thanks to
the Almighty for being my guiding light for showing his blessings
on me for partly fulfilling my dream. I thank him for equipping me
with atmost strength and patience, to combat all the hurdles that
come in the way of completing this task.
I with an overwhelming sense of pride and genuine
obligation, I take this rare opportunity and proud privilege to
extent my heartful and deep sense of gratitude towards my
esteemed
Chairman
of
my
advisory
committee,
Dr. D. Chandrappa,
Chandrappa Professor and Programme Co-ordinator, KVK,
Babbur Farm, Hiriyur for his valuable and expert guidance,
timely suggestions, close counsel, critical evaluation, everlasting
patience and constant encouragement for present investigation
and finalization of this manuscript. I am specially thankful for
giving me full freedom. It was indeed a great opportunity of mine
to work under his guidance. He deserves rich tributes and regards
indeed.
Words are inadequate to express my deep sense of gratitude
for the encouragement, guidance and cooperation of the member of
my advisory committee, Dr. T.K. Narayanaswamy,
Narayanaswamy Professor and
University Head, Department of Sericulture, UAS, GKVK,
Bangalore.
I feel immense pleasure in expressing my deep sense of
gratitude, esteem and sincere feelings of indebtedness to
Dr. Chikkalingaiah,
Professor and Head, Department of
Chikkalingaiah
Sericulture, UAS, GKVK, Bangalore and the member of my
Advisory Committee for his valuable suggestions and sustained
cooperation during the course of investigation. Mere words of mine
cannot adequate to express my gratitude and respect towards
Dr. Ramakrishna Naika
Naika, Professor of Sericulture, College of
Sericulture, Chintamani and the member of my Advisory
Committee for his untiring knowledge, guidance and constant
encouragement were much more than deserved, without those, I
would not have been able to reach my destiny. I express my
reverence to Mr. Venkatesh, M, Subject Matter Specialist, KVK,
V.C. Farm, Mandya for having served as a member of my
Advisory Committee.
Thanks to the staff of KVK, Babbur Farm, Hiriyur and State
Department of Sericulture, Hiriyur, Chitradurga district, for
providing me the constant support to carry out my research.
My sincere thanks to Mr. Kemparaju, the Department of
Sericulture, Dr. Amarnatha, Assistant Professor of Sericulture,
College of Sericulture, Chintamani and Dr. Vijay Kumar, Assistant
Professor, Dept. of Entomology, College of Agriculture, V.C.Farm,
Mandya for their kind hearted support during all the stages of my
study.
I am thankful to all the faculty of Sericulture Department,
UAS, Bengaluru for their needy help in persuing my investigation.
I avail this opportunity to thank my parents who are the
Almighty’s most treasured gift to me. I feel words are scent for the
magnitude of love and affection showered on me by mother Smt.
Mamatha, father Sri.
Sri. Kalegowda whom I wish to idolize
throughout my life for making me what I am today. At this
moment, no words available in this world, I find sufficient to
express my profound love and feelings towards to my brothers
Guruprasad Gowda, Y.K. and Nandish Gowda,Y.K. niece without
whose affection, prayers and constant encouragement, I would not
have come up to this level. Their affection, care, loves and trust in
me helped me to achieve this status in life.
On a personal note, I express my sincere and heartfelt
gratitude to my sister Vasudha Prabhkar in whose presence I
never felt burden of my work. I thank for their mental support
love and affection, immoral help during the course of my study.
Above all, I express my warm feelings towards my dearest
friends Rajashekar Murthy, Madhu, Guruprasad, Madhusudan
adhusudan,
sudan,
Prasanth and Senior friend Muthu
Muthu raj, Sunil, Dananjay, Santhosh,
Santhosh,
Sandeep,
Mukund,
Ajey
and
Mahatab
Ali
For
their
Mukund,
encouragement and constant support during the period of my
research, at every junction and also I thank to Niveditha, Sowmya,
Kowsalya,
Kowsalya, Kirthi,
irthi, Radha, Swetha and Moulya.
Moulya.
I owe my thanks to my classmates Ananya,
Ananya, Gururaj,
Mamatha, Mala
Mala and Raksha Sharma,
Sharma, my senior friends Harish
Babu, Swathi, Sowmya, Madhuri and Anusha for their constant
encouragement, helpful criticism and enjoyable moments during
the study and suggestions for the improvement of thesis.
Above all, I bow my head before the Almightly who blessed
me with willpower and courage to overcome many hurdles and
graced me with a peaceful atmosphere to complete this endeavour.
Last but not least, I wish to express my indebtedness to all
those whose names might have been left over but without their help
my thesis would not have been seen the light of the day.
Bengaluru
July
July,
ly, 2014
(SHARANYAKUMAR GOWDA, Y.K)
THE PERFORMANCE OF DOUBLE CROSS HYBRIDS OF
SILKWORM, BOMBYX MORI L. IN CENTRAL DRY ZONE OF
KARNATAKA
SHARANYAKUMAR GOWDA, Y.K.
ABSTRACT
The performance of double cross hybrids of silkworm, Bombyx mori L., in
central dry zone of Karnataka” is detailed below. The hybrids viz., (CSR6 x CSR26) X
(CSR2 x CSR27), (CSR2 x CSR27) X (CSR6 x CSR26), (CSR2 x CSR4) and (PM X
CSR2) were reared on V1 variety of mulberry during 2014. The field study was
conducted to know the performance of double cross hybrid (CSR6 x CSR26) X (CSR2 x
CSR27) and (PM X CSR2) at farmers level in Chitradurga District and the economics of
cocoon production was calculated with the help of pre structured interview schedules.
Among the different hybrids reared, (CSR6 x CSR26) X (CSR2 x CSR27)
performed better for economic characters viz., I, II and III instar larval weight (0.061 g,
0.318 g and 2.122g/10 larvae), IV and V instar larval weight (8.52 g) and (43.33 g/10
larvae), cocoon weight (2.07 g), shell weight (0.488 g), shell ratio (23.57 per cent), silk
productivity (5.99 cg/day), filament length (1249.2 m), denier (2.66), cocoon yield/100
dfl’s (78.53 kg) and benefit cost ratio (1:2.7).
The field study also revealed that, double cross hybrid (CSR6 x CSR26) X (CSR2
x CSR27) performed better in respect of economic traits viz., single larval weight (38.91
g/10 larvae), cocoon weight (1.96 g), shell weight (0.429 g), shell ratio (21.84 per cent),
filament length (1174.1 m), filament weight (0.34 g), denier (2.65) and cocoon yield/100
dfl’s (75.6).
JULY, 2014
Department of Sericulture
University of Agricultural Sciences,
GKVK, Bengaluru-560065
D. CHANDRAPPA
(Major Advisor)
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CONTENTS
CHAPTERS
TITLE
PAGE NO.
I
INTRODUCTION
1-2
II
REVIEW OF LITERATURE
3-19
III
MATERIAL AND METHODS
20-26
IV
RESULTS
27-40
V
DISCUSSION
41-46
VI
SUMMARY
47-48
VII
REFERENCES
49-61
APPENDICES
LIST OF TABLES
Table
Title of the tables
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
Larval duration in different hybrids of silkworm, Bombyx mori L.
in different instars (First rearing)
Larval duration in different hybrids of silkworm, Bombyx mori L.
in different instars (Second rearing)
Larval parameters in different hybrids of silkworm, Bombyx mori
L. in different instar (First rearing)
Larval parameters in different hybrids of silkworm, Bombyx mori
L. in different instar (Second rearing)
Yield parameters in different hybrids of silkworm, Bombyx mori L.
(First rearing)
Yield parameters in different hybrids of silkworm, Bombyx mori L.
(Second rearing)
Economic parameters in different hybrids of silkworm, Bombyx
mori L. (First rearing)
Economic parameters in different hybrids of silkworm, Bombyx
mori L. (Second rearing)
Post cocoon parameters in different hybrids of silkworm, Bombyx
mori L. (First rearing)
Post cocoon parameters in different hybrids of silkworm, Bombyx
mori L. (Second rearing)
Economic parameters in double cross hybrids of silkworm,
Bombyx mori L. in farmers field level
Post cocoon parameters in double cross hybrids of silkworm,
Bombyx mori L. in farmer field level
Economics in cocoon production for hybrids of silkworm,
Bombyx. mori L. at farmer level
Page
No.
28
29
31
31
32
33
34
34
36
36
38
39
40
LIST OF FIGURES
Figure
No.
Title of Figures
1
First instar Larval duration in different hybrids of silkworm, Bombyx
mori L.
30-31
2
Second instar Larval duration in different hybrids of silkworm,
Bombyx mori L.
30-31
3
Third instar Larval duration in different hybrids of silkworm,
Bombyx mori L.
30-31
4
Fourth instar Larval duration in different hybrids of silkworm,
Bombyx mori L.
30-31
5
Fifth instar Larval duration in different hybrids of silkworm,
Bombyx mori L.
30-31
6
Total Larval duration in different hybrids of silkworm, Bombyx mori
L.
30-31
7
First instar Larval weight in different hybrids of silkworm, Bombyx
mori L.
32-33
8
Second instar Larval weight in different hybrids of silkworm,
Bombyx mori L.
32-33
9
Third instar Larval weight in different hybrids of silkworm, Bombyx
mori L.
32-33
10
Fourth instar Larval weight in different hybrids of silkworm,
Bombyx mori L.
32-33
11
Fifth instar Larval weight in different hybrids of silkworm, Bombyx
mori L.
32-33
12
Effective rate of rearing in different hybrids of silkworm,
Bombyx mori L.
Between
Pages
32-33
13
Cocoon weight in different hybrids of silkworm, Bombyx mori L.
34-35
14
Shell weight in different hybrids of silkworm, Bombyx mori L.
34-35
Figure
No.
Title of Figures
Between
Pages
15
Shell ratio in different hybrids of silkworm, Bombyx mori L.
34-35
16
Silk productivity in different hybrids of silkworm, Bombyx mori L.
34-35
17
Filament length in different hybrids of silkworm, Bombyx mori L.
36-37
18
Filament weight in different hybrids of silkworm, Bombyx mori L.
36-37
19
Denier in different hybrids of silkworm, Bombyx mori L.
36-37
20
Cocoon yield in different hybrids of silkworm, Bombyx mori L.
36-37
21
Benefit-Cost ratio in different hybrids of silkworm, Bombyx mori L.
40-41
LIST OF PLATES
Plate
no
Title of Plates
Between the
pages
1
View of silkworm rearing under laboratory condition
21-22
2
View of silkworm rearing in farmers house
25-26
3
Data collection from silkworm rearers
25-26
4
Fifth instar silkworm of different hybrids
32-33
5
Cocoons of different silkworm hybrids
34-35
I. INTRODUCTION
The silkworm, Bombyx mori L. is one of the important productive insects cultured
beneath the shade and exploited for silk of commerce. India is the second largest
producer of silk in the world with an annual silk production of 23,855 MT in 2012-13 of
which, mulberry raw silk output aggregated to 18,735 MT (79.06%) and bivoltine
contributes to 1675 MT (Anon., 2013).
The major silk producing traditional states are Karnataka, Andhra Pradesh, Tamil
Nadu, West Bengal and Jammu and Kashmir. Karnataka stands first by producing 7360
MT of the total silk production with 335.00 MT of bivoltine and 7025.00 MT of cross
breed (Anon., 2010).
In Karnataka, the major silk producing districts are Chikkaballapur (1253.99 MT),
Kolar (1499.03 MT), Ramanagar (1665.98 MT), Mandya (1597.09 MT) and Chitradurga
(713.67 MT) (Anon., 2012).In these districts, the cocoon crop varies according to the
method of mulberry cultivation and silkworm breeds.
India is one of the oldest country practicing sericulture and rearing of polyvoltine
silkworm is tradition of the country. Majority of Indian silk is from polyvoltine origin
produced by small scale operators which cannot compete in international market in
quality and uniformity. Therefore, there is a large scope for the increased production of
quality silk to cater to the need of power loom which could be possible only through the
successful introduction of bivoltine sericulture on large scale coupled with large scale
modern reeling unit. The evolution of bivoltine breeds suited to farmer’s condition, i.e.,
inferior management levels, poor quality mulberry leaves and fluctuating microclimatic
conditions thus become necessary (Quadri et al., 2013).
Sericulture as a viable position could be realized through many major factors
coupled with exploitation of superior breed to their optimum potential. The maximum
silk production of the country (80-85 per cent) is only from cross breed of multivoltines
which are poor both in quality and quantity. The international classification of silk ranges
from “4A” to “H” grade. While the silk produced in Japan, South Korea and Brazil fall
under superior grades, the Indian multivoltine silk grade as “H” in the international
market. Bivoltine breed, on the other hand possess filament length of more than 1000 m
per cocoon with finer denier and good quality (3A) (Somashekar, 1994).
With the advent of new technology of silkworm rearing for tropics, the situation
changed and use of the age old multivoltine x multivoltine crosses has been replaced by
multivoltine x bivoltine and bivoltine x bivoltine hybrids (Datta, 1984).
If India has to compete in the international market successfully and it is necessary
to improve the quality of the silk yarn produced by improving the technology of the silk
reeling and processing. But, production of raw silk of international grade is possible only
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
1
through introduction of newer bivoltine silkworm strains especially double cross hybrids
(Dayananda et al., 2011)
India has strong sericultural base with enormous potential for boosting silk
production. In India’s context, stability of double cross hybrid with higher survival is
more relevant than higher productivity under prevailing situation. The stability of
bivoltine crop was not achieved mainly due to climate, rearing and socio-economic
conditions. This necessitated evolution and evaluation of the double cross hybrid
silkworm breeds for increased cocoon and gradable raw silk production (Joge et al.,
2003)
Double cross hybrids recorded more than 94 per cent pupation and 23 per cent
shell ratio under Karnataka condition (Mal Reddy et al., 1998).
Suitable bivoltine double cross hybrids with production traits viz., advantages of
rearing and increased fecundity (13%) for commercial exploitation were identified which
could be popularized in India. In spite of all the advantages, double cross hybrids concept
was exploited to an extent of 40 per cent (Nirmal Kumar et al., 1999).
The favorable regions recommended for bivoltine double cross hybrid rearing in
India, (CSR6 X CSR26) X (CSR2 X CSR27) are Karnataka, Andhra Pradesh, Tamil
Nadu and Jammu and Kashmir and seasons are spring and autumn (Anon., 2005).
Considerable research work on the performance of bivoltine double
hybrids in Karnataka, particularly in Central Dry Zone (CDZ) of Chitradurga district was
not done. Hence, the study was taken to determine the suitability and economics of
rearing double cross hybrids on V1 variety of mulberry. The following objectives.
1. To Study the performance of double cross hybrids of silkworm, (Bombyx mori L.)
2. To document the rearing performance of double cross hybrid at farmers (field) level.
3. To study the economics of double cross hybrids.
2
Sharanyakumar Gowda, Y.K.
II. REVIEW OF LITERATURE
The literature available on the performance of double cross hybrids of Bombyx
mori L. with respect to economic parameters, yield and economics of production in
comparison with bivoltine hybrid and cross breed are reviewed here under:
Indian sericulture remains multivoltine and bivoltine single cross oriented
producing low productivity of silk with poor quality. Suitable silkworm hybrids play a
vital role in increasing the productivity and quality of silk which are important for
sustainable sericulture industry (Subba Rao, 1994).
2.1. Performance of silkworm breeds
2.1.1. Cross breed
Sidhu et al. (1969) and Sengupta (1969), reported that during the early and later
part of 1960s, several attempts were made by Indian breeders to replace the indigenous
multivoltine breeds resulted in the isolation of improved breeds such as, Kollegal Jawan,
Mysore Princes, Tamil Nadu White, Kolar Gold, Hosa Mysore and MY1. However,
exploitation of these breeds was not advantageous due to their instability under field
conditions.
Suresh Kumar and Toshi Yamamoto (1996), reported that unlike Japan, the
concept of bivoltine hybrids is not popular in India, because majority of the newly
developed bivoltine breeds were used only as male components for the preparation of
multivoltine x bivoltine hybrids. This could be mainly attributed to the fact that more
than 85 per cent of Indian farmers rear only multivoltine x bivoltine hybrids.
Nirmal Kumar and Sreerama Reddy (1998), evaluated the performance of nine
multivoltine breeds among which, Kolar Gold ranked third based on larval period,
pupation rate, cocoon weight, shell weight and cocoon yield by weight, where as C. Nichi
ranked first and Mira, Guangnong ranked second.
Maribashetty et al. (1998), reported that sericulture in India is mostly multivoltine
oriented and depend on multivoltine x bivoltine hybrids of indigeneous pure Mysore and
tropical bivoltine races.
The PM X CSR2 recorded highest shell ratio (19.2%), filament length (690 m),
non-broken filament length (514 m) and filament size (2.39 d) compared to other breeds
(Anon., 2004b)
Kariappa and Rajanna (2004), noticed an improvement in multivoltine x
multivoltine and multivoltine x bivoltine hybrids with highest yield (50-55kg/100 dfls),
cocoon shell ratio (18-19%) and low renditta (7.5).
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
3
Dandin et al. (2005), reported that though the traditional polyvoltine x bivoltine
hybrids viz., Kolar Gold, Kollegal Jawan, Mysore Princes and Tamil Nadu white were
low in productivity, they were suited for rearing under fluctuating temperature and poor
hygienic conditions. Hence, they were popular among resource poor farmers. The
economic parameters for five polyvoltine x bivoltine hybrids revealed highest pupation
rate (97%) in PM x CSR2. The sex limited PM x CSR2 was on par with PM x CSR2 and
superior over PM x CSR8 and PM x NB4D2 (control hybrid) in yield with marginal
improvement in reeling characters.
The spring, summer, autumn and winter as favorable season for rearing PM X
CSR2 at Andhra Pradesh, Karnataka and Tamil Nadu (Anon., 2005)
Datta et al. (2006), reported that the multivoltine x bivoltine cross breeds can be
reared in eastern region of India with better cocoon yield during three commercial crop
season, viz., January – February (spring), March (early summer) and November –
December (Autumn).
Munikrishnappa et al. (2007), reported that Licensed Seed Producers and reelers
were of the opinion that the Kolar Gold has a steady and higher demand in Sericulture
industry as the farmers preferred it for higher crop stability and assured cocoon price.
2.1.2. Bivoltine hybrids
In India, the concept of introducing hybrids for commercial silkworm rearing
started in 1922 and Karnataka was the first state in introducing crosses between pure
Mysore and Japanese races, namely, PM X C. Nichi and PM X HS6 (Nanavaty, 1965)
and thus the tradition of rearing hybrids instead of pure races was started in South India
(Datta, 1984).
F1 crosses between indigenous Nistari and Exotic uni or bivoltine races were
introduced in west Bengal since 1956. F1 era in Jammu and Kashmir started in 1959
when two important crosses from Japan, viz., Taihei x Choan and Hoko X Chugyoko
were tried. Uttar Pradesh is utilizing Nistari and pure Mysore hybrids with bivoltine like
NB4D2 and KA (Jolly, 1983; Datta, 1984).
According to Jolly (1983), the bivoltine hybrid rearing is a significant phase of the
sericultural development in the southern parts of the country. Bivoltine as a commercial
hybrid is yet to make a big impact. The first attempt to rear bivoltine hybrids in large
scale in the field were made in the south in early 1970’s. KA X NN6D, KA X NB4D2 and
NB7 x NB18 were the popular hybrid combinations used in the field.
The CSR & TI, Mysore evolved nineteen new bivoltine lines out of which, three
race’s namely, NB4D2, NB3C1 and NB1C performed better as pure races than KA x NN6D
of many combinations studied, KA x NB4D2 and its reciprocal had given encouraging
result with survival rate of 80 per cent, yield ranging from 50-80 kg/100 DFL’s with
cocoon weight 2g, shell weight 0.4g and renditta 6.5. Realizing its potentiality the same
4
Sharanyakumar Gowda, Y.K.
combination was released into the field as ‘Nandi’ hybrid (Anon., 1975; Narasimhanna et
al., 1976).
Datta (1984), reported that the reelability percentage was very high in new hybrids
(JC1 x KA and JC1 x NB7) compared to that in existing hybrids (NB17 X NB18). The
renditta in the new hybrid had registered only 5.03 as against 6.63 in NB7 x NB18.
Further, he stated that CSR & TI, Mysore in 1970’s evolved two bivoltine breeds viz.,
KA x NB4D2 from exotic hybrids and their cross was named as ‘Nandi hybrid’. Later on,
two bivoltine breeds NB7 and NB18 were evolved and their F1 was released into the field
as ‘Chamundi hybrid’. NB7 x NB18 cross performed well compared to parents in almost
all characters, namely, hatching percentage, larval weight, shell ratio, filament length and
denier. Besides, there was also reduction in total larval duration, fifth instar larval
duration, melting cocoon percentage and number of cocoon per liter compared to parents.
Teli et al. (1984), reported that Mysore hybrids (NB7 X NB18 and NB18 X NB7)
were more efficient than wai-strains under Kolhapur (Maharashtra) conditions. But, more
floss which is undesirable character was noticed in the Mysore-hybrids.
Jolly et al. (1986), reported that PCN x Bivoltines and their reciprocals were
subjected to summer trails and pupation rate was 87.5 to 94.8 per cent with pupation rate
of 93.25 per cent at 32oc. Similarly, the bivoltine hybrid, CPP1 x NB18 recorded shorter
larval duration (22.02 days) with 1.988g. 0.40g and 20.4 per cent cocoon weight, shell
weight and shell ratio, respectively. Further, the cross CPP1 x NB18 was found to be
superior to existing cross in almost all economic characters.
Two high yielding bivoltine breeds, namely, CC1 and CA2 was released by CSR
&TI, Mysore during 1986. Out of which, CC1 was found to be superior to CA2 and
preliminary yield trails conducted with hybrid CC1 X NB4D2 recorded 45-55 kg of
cocoons per 100 DFL’s with a renditta of 7.0 (Ramamohan Rao et al., 1987).
Venugopala Pillai et al. (1987), reported that the bivoltine hybrids (KA XNB4D2,
NB4D2 X KA, KA X NB18, NB7 X NB18, NB4D2 X NB7, NB18 X NB7 and NB18 X KA)
reared on local variety purely raised under rainfed conditions recorded the average
cocoon yield ranging from 38 to 45 kg/100 DFL’s. The maximum cocoon yield was
recorded during July to February period (45 to 55 kg/100 DFL’s), but minimum yield
was recorded during March to June period (30 to 40 kg/100 DFL’s).
Basavaraja et al. (1995), reported that CSR2 x CSR4 was on par with seven
bivoltine hybrids for various parameters viz., yield, single cocoon weight, single shell
weight, shell ratio, raw silk percentage, filament length, denier, reelability, neatness and
renditta.
Basavaraja et al. (1996), reported that the bivoltine hybrids, CSR2 x CSR4, CSR4
x CSR2, CSR3 x CSR6, CSR12 x CSR6 and CSR12 x CSR5 performed better than KA x
NB4D2 with respect to cocoon shell weight, shell ratio, raw silk and filament length.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
5
Nirmal Kumar et al. (1996), evaluated the field performance of productive
bivoltine hybrids, CSR2 x CSR4 and CSR2 x CSR5 for their quality oriented yield
potentiality. Both the hybrids recorded an average cocoon yield of 41.64kg/100 dfls in
the first trial and above 62.0kg/100 df’ls in the second and third trials.
Das Mohapatra et al. (1997), reported highest shell ratio of 23.15 per cent and 22
per cent for CSR2 x CSR5 in the spring and autumn, respectively than CSR2 x CSR4
(22.9% and 21.85%).
Krishna Rao et al. (1997), opined that new bivoltine silkworm hybrids viz., CSR2
x CSR4, CSR18 x CSR19, CSR2 x CSR5, NP2 x KSO-1 and KSO-1 x NP2 had the
advantage of lesser mortality, higher cocoon weight, increased shell weight, increased
filament length and more uniform cocoons compared to pure races.
Among the new bivoltine hybrids, viz., CSR2 x CSR5, CSR2 x CSR4 and SH6 x
NB4D2 revealed that CSR2 x CSR4 recorded higher weight of ten mature larvae (56g)
and cocoon weight (1.92g) (Anon., 1998).
Nirmal Kumar et al. (1998), reported that CSR2 xCSR4 and CSR2 x CSR5
performed better than the check, KA x NB4D2 in terms of silk ratio percentage, raw silk
percentage, filament length and neatness.
Fotadar et al. (1999), suggested that there was enough scope for introduction of
new CSR bivoltine silkworm hybrids, viz., CSR2 x CSR4, CSR1 X CSR4, CSR4 x
CSR1, CSR2 x CSR5 and CSR3 x CSR6 in the sub–tropical region of Jammu which
could help in improving the quality of cocoons together with increased yields.
The evolution of that three silkworm hybrid combinations, viz., SH6 x NB4D2,
CSR2 xCSR4 and CSR5 x CSR2 in the field during spring season recorded an average
yield of 57.65 kg/oz in CSR2 x CSR4 against 44 kg/oz in the ruling hybrid, SH6 xNB4D2
(Anon., 2002).
The introduction of hybrid, CSR2 x CSR4 during 1997 has revolutionized the
Indian sericulture in the production of quality silk (Anon., 2003a). The yarn of CSR
hybrid was comparable to international standards of 2A to 3A grade (Daniel et al., 2000).
Akio Yamaguchi (2001), reported that the bivoltine hybrid, CSR12 x CSR6
registered maximum cocoon weight (2.10g). Shell ratio was maximum in CSR3 x CSR6
(24.40%) and the denier was high in CSR2 x CSR4 (3.2).
Roopa V. Temker (2002), observed an increase in larval weight to the tune of 7.2
per cent and ERR (1.6 to 1.8%) in CSR18 x CSR19 and CSR2 x CSR4 over PM x
NB4D2 in summer and winter.
6
Sharanyakumar Gowda, Y.K.
Kishore et al. (2002), reared 15 bivoltine x bivoltine hybrids and concluded that,
the hybrids differed 5 per cent significantly from each other. The hybrids, CSR2 x CSR4,
CSR2 X CSR5 and CSR16 x CSR17 exhibited higher economic parameters.
Combine ability studies conducted by showed that CSR2 x CSR4 exhibited
highest reelability of 88 per cent with neatness of 90 points. The better performance of
SH6 x NB4D2, CSR2 x CSR4 and CSR2 x CSR5 was also reported by (Anon., 2004a).
Quadir and Mir Nisar (2004), evaluated ten short listed hybrids during spring and
autumn season among which highest shell ratio (21.97%) and filament length (812 m)
was recorded in Pam-101 x CSR2 and CSR2 x CSR5 (22.73% and 835m) during spring.
During autumn CSR2 x CSR4 recorded highest shell ratio (22.40%) and SH6 x Pam11
recorded the highest filament length of 813m.
Quadir et al. (2005), identified CSR2 x KY1, JP1B x Pam101, J-Plain x CSR5
and CSR2 x CSR4 as season specific hybrids for Kashmir. They recorded shell ratio of
21 per cent and yield of 16.32 to 16.50kg/10,000 larvae. They also reported that among
the five hybrids, (CSR2 x CSR4, SBGP5 x SBGP20, SBGP20 x CSR2, JP1B x SBGP5
and SH6 x NB4D2) CSR2 x CSR4 recorded highest fecundity (598). It was on par with
other hybrids for parameters like yield/10,000 larvae (15.80kg by wt. and 96.93 by no.),
cocoon weight (1.63g), shell weight (0.35g), shell ratio (21.47%), filament length (980m)
and denier (2.35)
Dandin et al. (2005), recorded various characters for CSR2xCSR4 viz., pupation
rate (ranged from 95-97%), cocoon shell ratio (23-24%), filament length (1000-1150m),
filament size(2.9-3.2d), raw silk percentage (19-20%), neatness (93-95 points), reelability
(80 – 85%) and renditta (5.0 -5.5).
According to CSR & TI, Pampore CSR2 x CSR4 breeds was confirmed as spring
specific hybrid for Kashmir which recorded 64kg cocoons/40,000 larvae (Anon., 2002)
2.1.3 Double hybrid
Double cross hybrids find an edge over single cross hybrids in respect of
increased moth emergence and fecundity and easy rearing (Yokoyama, 1959;
Pannengpet, 1973).
Krishnaswami et al. (1973), stated that the seed production in double cross
hybrids become easy rearing and cheap since second stage seed cocoon crop is easily
reared as rearing involves F1’s. To produce double cross eggs, usually two allied strains
say Chinese x Chinese and Japanese x Japanese type are crossed first and F1 hybrids
produced are crossed to produce the double cross eggs.
According to Yokoyama (1959), the government of Japan distributed half-double
cross hybrid eggs in 1925 and double cross hybrids eggs in 1946.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
7
Strunnikov (1983) stated that in USSR, tetra-hybrids were being reared instead of F1
hybrids. Tetrahybrid-3 and Tetrahybrid-4 were commercially used.
Tanaka et al. (1980), developed the double cross hybrid (N142 x N143) x (C142 x C143)
where in each parent strain had sex limited characters. The economic character of the
race superb, especially the neatness was excellent but boiling off ratio of cocoon shell
was low.
Benchamin and Krishnaswami (1981), reported that polyhybrids were most
advantages in egg production for commercial exploitation. Polyhybrids were in general at
slight disadvantage when compared to F1s. However, specific combinations like (KA x
NB7) x (NB4D2 x NB18) and its reciprocal have behaved on par or even better than most
of the foundation crosses. Further, they opined that polyhybrids of better productivity can
be made if the parental stock are selected and combined properly.
At CSR & TI, Mysore, studies conducted on performance of double cross hybrids
revealed superiority of (NB4D2 x NB18) x (2C1SS x NB3C1) to (NB18 X M8) (2C1SS x
NB7) with respect to fecundity, hatching percentage, yield per 10.000 larvae brushed and
single cocoon weight and shell ratio (Anon., 1982).
The inbreed lines SPC1 and SPC2 of Chinese type and SPJ1 SPJ2 of Japanese type
were tried for double cross hybrids. The results indicated that there was a marginal
improvement in the foundation crosses of Japanese type, whose parents were low in
survival rate, but the double cross was significantly superior which showed marked
hybrid vigour. The larval duration reduced by one day improvement over better parent
out to be per cent in survival rate, 47 per cent in cocoon yield, 29 per cent in cocoon
weight and 24 per cent in shell weight (Anon., 1983).
Basavaraja et al. (1983), evaluated the performance of silkworm double cross
hybrids in bivoltine strains. The results indicated that foundation hybrids were better than
the parents in respect of fecundity, survival, cocoon yield, cocoon weight and shell
weight. The double hybrids were better than the parents to a larger degree and over
foundation hybrids to a smaller degree. The double hybrids were superior to control F1
hybrid in egg number and cocoon characters.
Harada (1961) and Pannengpet and Jaroonchai (1975), demonstrated the
superiority of single hybrid, three way cross hybrid and double hybrids over their parental
races.
Narayanaswamy (1988), opined that double cross hybrid, (NB4D2 xNB18) x (KA
xNB7) and its reciprocal had the advantages of higher moth emergence, improvement in
fecundity, reduction in percentage of dead and unfertilized eggs, maximum hatching,
larval weight, silk gland weight, reduction in the fifth instar and total larval duration,
increase in yield both by number and weight, pupal weight, shell weight shell, ratio, less
occurrence of defective cocoons, increase in cocoon filament length, denier, reduction in
number of breaks per cocoon filament and increase in productivity.
8
Sharanyakumar Gowda, Y.K.
Govindan et al. (1990), reported that the variability in weight of larva, silk gland,
cocoon, cocoon shell and cocoon shell ratio in four bivoltine mulberry silkworm races,
four single cross hybrid and eight double cross hybrids. They attributed that the double
cross hybrids had higher values for the traits compared to single cross hybrids and pure
breeds at five per cent level of significance.
Highest survival of 98.9 per cent was observed in double hybrid (CSR6 x B62) x
(CSR3 x A61) followed by (CSR6 xB61) x (CSR3 xA63) (93.5%). These double hybrids
also recorded better cocoon shell ratio (24.0%, 24.1%), cocoon filament length
(1191m,1200m) and neatness (92,98), respectively (Mal Reddy et al., 1995).
Basavaraja et al. (1996), based on evaluation index and subsequent short listing,
identified three promising double hybrids which recorded higher survival (>91.0%), shell
ratio (>23.7%), raw silk percentage (<18%) and filament length (<1115m). These double
hybrids, viz., (CSR6 x B65) x (A66 x A69), (CSR6 x B72) x (70 x A66) and (CSR6 x
B60) x (CSR6 x A60) also recorded highest pupation rate of 97.0 per cent, 95.3 per cent
and 94.8 per cent respectively. Similarly, (CSR6 x B65) x (A66 x A69) recorded higher
cocoon shell ratio of 24.7 per cent with raw silk recovery of 19.9 per cent.
Mal Reddy et al. (1998), developed the hybrids (CSR6 x CSR26) x (CSR2 x
CSR27) and (CSR6 x CSR26) x (CSR21 x CSR29) which registered a pupation rate
(24.2%) and raw silk percentage (19.85%) in (CSR6 x CSR28) x (CSR3 x CSR37).
Nirmal Kumar et al. (1998), short listed three hybrid combinations, namely DH1,
DH2 and DH3 based on overall index value (>50) and uniformity which matched the
present day demand by grainers, cocoon producers and reelers.
Sohn and Ramirez (1999), reported that the three – way and double cross hybrids
presented higher yield and higher percentage of reelable cocoons than the single cross
and double cross hybrids.
Highest values for reproductive indexes (number and weight) of eggs per laying
was obtained by for the tetra-hybrid followed by triple hybrid and double-hybrids. He
also reported highest variability of the basic selection indexes (cocoon weight, weight of
silk, cocoon shell weight, cocoon shell ratio and length of silk filament) for the tetra
hybrids followed by triple and double hybrids (Petkov et al., 2000).
The salient features of double hybrids included higher cocoon yield (60-70kg/100
dfl), higher pupation (92-95%) and increased fecundity (600-650) (Anon., 2003a).
Mal Reddy et al. (2003), selected the double hybrid, (CSR6 x CSR26) x (CSR2 x
CSR27) for race authorization based on pre and post cocoon parameters, cocoons
uniformity test and multi trait evaluation.
Joge et al. (2003), reported the stability of double hybrids with an average yield of
62.07kg/100 dfls.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
9
Naseema Begum et al. (2005), reported that the performance of double hybrids
(CSR2 x CSR27) x (CSR6 x CSR26) was better than that of the Chinese hybrids Viz.,
YX1, YX2, MC18 x HY01, YN2 x YN1 and NF x SX based on larval period, fifth age
period, pupation rate, cocoon weight, shell weight, shell ratio, filament length, filament
denier, reelability, raw silk percentage and neatness.
The bivoltine hybrid (CSR2 xCSR27) x (CSR6 x CSR26) produced an average
cocoon yield of 65kg/100dfls (Anon., 2007).
According to Manimegalai and Aruna (2010 a) the average cocoon price was high
for double hybrid (CSR6×CSR26) × (CSR2×CSR27) (Rs. 142 to 150 per kg) as
compared to CSR2 × CSR4 (Rs. 138.15 to 145.00 per kg) and PM × CSR2 (Rs.121.05 to
127.45 per kg).
Manimegalai and Aruna (2010 b), reported that the economic parameters namely,
larval weight, cocoon weight, shell weight, silk productivity, filament length, denier,
yield per 10,000 larvae and yield per 100dfls was superior in (CSR6×CSR26) ×
(CSR2×CSR27) and its reciprocal cross (CSR2×CSR27) × (CSR6×CSR26) compared to
CSR2×CSR4, whereas, shell ratio was registered maximum in CSR2×CSR4.
Dayananda et al. (2011), studied on the evaluation and identification of promising
bivoltine double hybrids of the silkworm Bombyx mori L. for tropics through large scale
in-house testing. The performance of the reeling traits were also found significantly
superior in [D7 × S5] × [D13 × S1] with higher filament length (1100 m), reelability
(88%), raw silk (18.55%) and neatness (92 points) compared to CSR2 × CSR4 and other
double hybrids evaluated.
Suresh Kumar et al. (2011), studied the impact of high temperature - humidity,
temperature – low, high humidity, on the performance of different double cross hybrids
viz., (HH1×HH3) × (HH8×HH12), (HH1×HH3) × (HH10×HH12), (HH3×HH6) ×
(HH8×HH12) and (HH3×HH6)×(HH10×HH12). Pre and post cocoon characters were
showed varied results under different environmental conditions.
Lakshmanan and Suresh kumar (2012), revealed a new double hybrid (SLD2 x
SLD4) x (SLD8 x SLD9) has shown desirable manifestation of heterosis in nine out of
thirteen traits and hetero beltiosis in seven out of thirteen traits taken up for the study,
which may be attributed to better genetic advancement obtained in the breeding study.
Mal Reddy et al. (2012), reported that the hybrids involving FCs up to F3
generation are on par with the hybrids involving FCs of F1 generation. However,
reduction in majority of characters and more cocoon variability was recorded in hybrids
combinations involving FCs at F4 generation. It is inferred that the hybrid involving
parental FCs up to F3 can be utilized for commercial exploitation.
10
Sharanyakumar Gowda, Y.K.
Veeranna Gowda et al. (2012), evaluated 45 different double cross hybrids,
among which 21 double cross hybrids showed superiority in Multiple Trait Evaluation
Index (MTEI) when assessed with control (CSR2×CSR27) × (CSR6×CSR26).
Qadri et al. (2013), studied that the evaluation and selection of three- way cross
bivoltine silkworm hybrids of Bombyx mori L. for commercial exploitation. The hybrids
viz., FC3 x CSR17, FC1 x CSR2, FC3 x CSR2 and FC1 x CSR17 have been identified as
the best combinations in the order of merit with evaluation index >59.0. The validation of
these hybrids is being carried out under on - station / on - farm testing to select the
suitable hybrids for commercial purpose.
Veeranna Gowda et al., (2013), made a study on evaluation and identification of
potential bivoltine silkworm hybrids of Bombyx mori L. It is inferred that, six promising
three-way cross (DxD) x O hybrids viz., [(D13 x S9) x CSR17], [(S9 x CSR26) x JPN8],
[(D13 x CSR26) x CSR27], [(CSR16 x CSR26) x CSR17], [(S9 x CSR16) x CSR27] and
[(D13 x CSR26) x CSR17] were identified as promising ones based on performance, E.I.
values and heterosis for majority of the traits in three different seasons and preserve
commercial exploitation.
2.2. Performance of silkworm breeds at farmer field level
Pannengpet (1973), conducted a survey in Thailand on practical characters of threeway and double cross hybrids. Among double cross hybrids, (K1 × T dai) x (K4 × T dai)
was found to be superior with respect to single cocoon weight compared to other double
cross hybrids.
Pannengpet and Jaroonchai (1975), conducted a survey on seasonal variation in
performance of double cross hybrids. The double cross hybrids showed shorter larval
duration, higher survival rate, cocoon weight, cocoon shell weight and shell ratio
percentage in October season than in January season. They also observed that (K7 x K10)
x (K6 x K1) was found superior to rest with respect to above mentioned commercial
characters.
According to Zulawska (1981), most of the commercial hybrids of Poland were
polyhybrids, developed in the country. The polish silkworm polyhybrids were
characterized with a 23 per cent of raw silk and a filament length of about 1200m. These
polyhybrids were also performing well in Algeria, Bulgaria, Ethiopia, Rumania, Turkey
and USSR.
The studies conducted on performance of double cross hybrids revealed
superiority of (NB4D2 x NB18) x (2C1SS x NB3C1) to (NB18 X M8) (2C1SS x NB7) with
respect to fecundity, hatching percentage, yield per 10.000 larvae brushed and single
cocoon weight and shell ratio (Anon., 1982).
Kamajyo et al. (1985), studied the performance of double cross hybrid (N132 x
N135) x(C132 x C136) and the results revealed that it was characterized by easy rearing
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
11
and high productivity of eggs, with high raw silk percentage of cocoon shell, good
neatness, low degumming loss and denier of about 2.7.
The cocoon produced by farmer showed that maximum single cocoon weight (1.64
g), single shell weight (0.34g), shell ratio (20.0%) and filament length (841 m) was in
CSR2 X CSR5. Whereas CSR3 X CSR4 recorded good reelability (85.7%) and lower
renditta (7.16) (Anon., 1995).
Krishna Rao et al. (1997), studied the performance of NP2 x KSO1, SP2 X KSO1,
KSO1 X KSO2 and KSO1 x SP2 during summer season in malnad region. All hybrids
produced 61 to 64 kg cocoons per 100 dfls. While in Bangalore, the average yield was 40
kg per 100 dfls. Further, the cocoons produced by farmer recorded 1.66 g, 0.34 g and
20.5 percent of cocoon weight, shell weight and shell ratio, respectively.
Nirmal Kumar et al. (1999), field tested 5 hybrids viz., CSR1 X CSR4, CSR2 X
CRS4, CSR2 X CSR5, CSR3 X CSR6 and CSR10 X CSR11. Among all the hybrids
tested, CSR2 X CSR4 showed promising result in the field with respect to raw silk and
fibre quality.
Rajan et al. (2000), reported that CSR hybrids performed well in at Varthur and
recorded highest cocoon yield of 81.30 Kg per 100 dfls and lower renditta of 5.40.
Further, about 25 per cent of farmer harvested 70 kg of cocoons per 100 dfl’s by rearing
CSR hybrids.
Datta et al. (2001), conducted a field trial with CSR hybrids. The hybrids
recorded an average cocoon yield of 66.7 Kg/100 dfl’s, 5.0 to 6.1 renditta and 2A-4A
grade raw silk.
Field performance of the multi x bivoltine hybrids MH1 x NB4D2 revealed
increased cocoon shell ratio (18.5%), filament length (977m), higher reelability (92%),
raw silk percentage (12.80) as compared to the PM x NB4D2. (Rajanna et al., 2001).
Kalappa (2001), studied the performance of the newly authorized polyvoltine x
bivoltine hybrid BL24 x NB4D2 in three different location of Karnataka and reported an
increase of 8.65 and 9.23 kg of cocoon yield per 100 dfl’s in Mysore and Mandya district,
respectively with PM x NB4D2 hybrid.
According to Saraswat et al. (2003), the bivoltine hybrid CSR2 XCSR4 showed
best performance as compared to other hybrids in Purvanchal agro- climatic condition.
Gangwar (2011), made a study on screening of popular bivoltine silkworm
(Bombyx mori L.) hybrid breeds of West Bengal in Mansoon and Autumn seasons of
Uttar Pradesh climatic condition. The selected breeds were reared in triplicates, data was
collected for the nine performance parameters viz. hatching percentage, yield / 10000
larvae by number, by weight, survival percentage, cocoon weight, shell weight, shell
percentage, total larval duration, filament length and reelability percentage. On the basis
12
Sharanyakumar Gowda, Y.K.
of results achieved, it is analyzed that SH x KA, KA x NB4D2 performed better in
monsoon and autumn seasons of Uttar Pradesh.
2.3 Economics of mulberry and cocoon production
2.3.1 Cost of establishing of mulberry garden
Narasimhanna (1973), pointed out that, under the improved technology leaf
production was 30000 kg per hectare and it reared 4000 layings, producing 1600 kg of
bivoltine cocoon. On the other hand, existing farmer practices produced only 15000 kg of
leaf that reared 3000 layings and produced 750kg of multivoltine cocoons. The returns
per rupee of investment was Rs. 2.68 under the improved technology, while it was less
than one rupee under the farmer practice
Murthy (1977), estimated that establishing of one hectare of mulberry garden
under irrigation condition in Devanahally taluk of Bangalore district was Rs.1676.55. The
major components of the cost were land preparation (Rs. 851.48) and planting material
(Rs.825.07).
According to Aiyaswamy (1980), the establishing cost of mulberry garden in
Coimbatore District was Rs. 2477.28 per hectare.
Jolly (1982) worked out the cost of establishing of mulberry garden in Karnataka to
be Rs. 4100 and Rs.3400 per hectare, under rainfed and irrigation condition, respectively.
Chandrasherkar Reddy (1985), computed the per hectare total cost of establishing
under irrigation, in Dharmapuri district of Tamil Nadu to be Rs.8860.72. The establishing
required 197.85 man-days of human labour, 22.75 days of bullock labour, 2.52 cart load
of mulberry cuttings, and 61.83 cartloads of farmyard manure and 52.27 kg of fertilizers.
Rama Krishna (1987), reported that the costs of establishing of mulberry garden per
hectare in T.S. hally, Jagamohanahally and Sugatur village in Kolar district, Karnataka,
was Rs. 3268.80, Rs.3500.05 and Rs.3524.65, respectively.
According to Karutagi (1991), total cost of establishment of one hectare of mulberry
garden under irrigated condition in Jamakandi taluk of Bijapur district was Rs.2111.17
and comprised of land preparation (Rs 663.50) and planting cost (Rs.1447.67).
Vijayalakshmi et al. (1991), studied the influence of sericulture enterprise on
employment generation in Nalgonda district of Andhra Pradesh. The total human labour
requirement per hectare for establishing mulberry garden worked out to be 348 man-days
and that of bullock labour was 88.35 workdays. The share of family human labour and
bullock labour in establishing mulberry garden was 49.24 per cent and 40.55 per cent,
respectively. Shah (1993) estimated the cost of establishing of mulberry garden as
Rs.4325 per hectare in Kashmir.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
13
2.3.2. Economics of cocoon production
The study conducted by Nanja Reddy et al. (1971), revealed that the total cost of
silkworm rearing was Rs. 9205.75 per hectare. The gross and net returns per hectare were
Rs. 16878.8 and Rs.7673.1, respectively.
Kasiviswanathan and Krishnamurthy (1972), compared the cost of silkworm cocoon
production under farmer practices under recommended package of practice, one kg of
cocoon production was reduced from Rs.7.46 to Rs.4.90.
Krishnamurthy (1972), reported the possibility of producing more than 30000 kg of
good quality mulberry leaves to harvest 1500 kg of bivoltine silk cocoons per hectare of
mulberry under irrigation. He observed that the possible yield of 150 kg silk per hectare
of irrigated mulberry garden in Mysore state was far above the average yield of 126 kg
obtained in Japan.
It is possible to obtain a net income of Rs. 11000 per hectare of mulberry by
rearing bivoltine under the new package of practices (Anon.,1973).
Karennavar (1973), observed that the yield of mulberry crop under irrigation was
three to four times higher than that obtained under rainfed condition in Karnataka. The
cost of leaf production per hectare of irrigated mulberry was Rs.3300 in 1968, as
compared to Rs.2500 in 1965. He advocated increases in mulberry area, procurement of
quality laying and increase care of young worm in order to improve the quantity and
quality of cocoons.
Venakata Rao (1974), reported that the net income from one hectare of sericulture
in irrigated land was about Rs.12000 or about four times the income possible from one
hectare of the same under rain fed conditions. Improved practices were found to reduce
the cost of production of mulberry leaves from Rs.0.25 to Rs.0.16 per kg. Rearing
bivoltine according to recommendations increased the annual net income from Rs.6000 to
Rs.27500 per hectare.
Devaraj Urs (1976), enlightened upon the capacity of Indian sericulture to create
more jobs with minimum capital investment. Capital investment required providing a job
in sericulture industry was around Rs.500 as against Rs.10000 in the organized textile
industry and Rs.3 lakh to Rs.10 lakh in the cement or steel industries
Narasimhanna and Kasiviswanathan (1976), estimated the cost of maintenance of
mulberry garden for the second year onword at Rs.8935 per hectare. Intercultivation
through manual digging (Rs.2600) was the major cost of item fallowed by fertilizers
(Rs.2093) harvesting of mulberry leaves (Rs.2000) irrigation (1144) and FYM (Rs.750).
Nataraj and Mathew Thomas (1976), based on their survey in 15 villages of
Karnataka reported that the yield of bivoltine, multivoltine hybrid and traditional hybrid
14
Sharanyakumar Gowda, Y.K.
were 31 kgs, 27 kgs and 21.5 kg per 100 dfl’s, respectively and grass income obtained
from these races were Rs. 990, Rs.780 and Rs.450 in that order.
Patel (1976), advocated the use of irrigation for mulberry through which per
hectare rainfed sericulture income could be quadrupled to Rs.6000 improved cultivation
of irrigated mulberry coupled with adoption of bivoltine rearing increased net income
from Rs.6000 to Rs.27500.
Murthy (1977), conducted a study in Devanahally taluk of Bangalore district
which revealed that the total cost of maintenance of mulberry was Rs.6331.48 per hectare
per annum under a irrigated condition, of which 33 per cent were operational costs and 67
per cent were fixed cost. The gross and net returns from mulberry cultivation were
Rs.13762 and Rs.7431, respectively, with a leaf yield of 25.38 MT. The cost of cocoon
production per annum was Rs.14082 with 93 per cent of it being operational costs. An
average of 4749 laying were reared per hectare per annum by obtaining 1128 kg. of
cocoons. The net returns per hectare were Rs.8203. Mulberry cultivation and cocoon
production employed 375 and 642 man-days. The proportion of family labour was 64 per
cent.
Sahabalmik and Mukhopadhyay (1977), reported cocoon yield of 1440 kg per
hectare per annum in West Bengal. A total cost of Rs.18067.50 was required for cocoon
production. The net profit was Rs.4292.50.
Ullal and Narasimhanna (1978), estimated the total cost of mulberry and cocoon
production at Rs.10500 and Rs.4670.4, respectively. The gross and net profits were
Rs.30000 and Rs.12976 in that order. Sericulture was found to be the more profitable
when compared to sugarcane, groundnut and paddy.
Aiyaswamy (1980), observed that the labour requirement was 607 man-days and
872 women days per hectare for the maintenance of garden and rearing of worms to
produce 957 kg of cocoon. The cost of production of one kg of cocoon was Rs.17.67, of
which variable cost alone was Rs. 13.82. The net return from one hectare of cocoon
production was Rs.7018.70.
Nanaiah (1981), reported that the sericulture was very profitable enterprise in
Karnataka and provided returns throughout the year, earning a gross income of Rs.15450
per acre by rearing 1313 dfl’s.
Jolly (1982), conducted a study in Karnataka and estimated the per hectare total
cost, gross and net returns at R.28725, Rs.55200 and Rs.2675, respectively for cocoon
production under irrigated conditions. Under rainfed condition per hectare cocoon
production cost was Rs.12110 and net profit was Rs.5390.
Neelakanta Shastry (1982), conducted a study in Chittur district of Andhra
Pradesh and reported that human labour and bullock labour requirement per hectare of
mulberry cultivation was 365.99 man-days and 15.51bullock pair days, respectively. This
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
15
increase with the decrease in the size of holdings, further the study revealed that the
average mulberry leaf yields was 20057.90 kg/hectare. He also mentioned that 2,968 dfl’s
were reared utilizing 1037.17 man-days and 15.51 per days of bullock labour. The total
cost of cocoon production was Rs.18322 yielding 1116.38 kg of cocoon and the
production costs per kg was Rs.16.41. the net income was Rs.17843.22 per hectare.
Siddappaji et al. (1983), observed that crop losses were low under shoot feeding
and was economical as it reduced the cost of production compared to leaf feeding. They
further started that providing shoots traditional accepted method and it was an
alternatively to leaf feeding in modern sericulture technology.
Chandrashekar Reddy (1985), in his study on economics of sericulture revealed
that the cost of mulberry leaf production in Dharmapuri district of Tamilnadu to be
Rs.12860 of which fixed cost accounted the operational costs, major expenditure was on
human labour (Rs.3553.90) fallowed by fertilizer (Rs. 1760.40), farmyard manure (Rs.
754.30), bullock labour (Rs.511) and irrigation charges (Rs.476). Similarly other charges
were on repairs, maintenance and interest on the working capital (Rs.357.40). The rental
value of land (Rs.2272.40) and interest on fixed capital (Rs.2048.70), constituted the
major items of expenditure in the fixed cost. The rest of the fixed cost included land
revenue, depreciation and interest on establishment charges. He further reported that the
cost of silk cocoons production per hectare was Rs.29930.65 in which the operational
cost was Rs. 28015.97 and the fixed cost was Rs. 1914.07. The returns from silk cocoons
was Rs. 49992.90. The net returns was estimated as Rs.20062.25/hectare / annum.
Giridhar et al. (1986), in their survey of eight districts of Karnataka revealed that
the mulberry was a subsidiary enterprise in which 65 per cent of the family-working
members were engaged. About 35 per cent of the male and 40 per cent of female
members were fully employed and the rest were intermittently employed. An acre of
mulberry yield four crops per year and reared 747 laying per annum. The study
conducted by Ramakrishna (1987) in Karnataka revealed that the total cost of
maintenance. (Rs.11183.86) than Jagamohanahally (Rs.9914, 56) and Sugatur
(Rs.9418.75). He also observed that the leaf yield was maximum in T.S.Hally (Rs.27279
kgs) when compared to the yields obtained by the farmer of Jagamohanahally (26633
kgs) and sugatur (25034 kgs). However, the net returns from one hectare of mulberry
garden was higher in Jagamohanahally (Rs. 8622.08) than T.S.Hally (Rs.7772.14) and
Sugutur (Rs.7672.23). Further, the cocoon yield per hectare was maximum in T.S.Hally
(1058 kg ) and than Jagamohanahally (1058 kg) and Sugatur (980 kg).
Chandrashekar Reddy et al. (1988), reported that mulberry cultivation and silk
production were increasing at a rapid rate particularly in the southern plateau of India.
Even the small farmer with meager capital base could make gross income of Rs.
1,99,971/- from an acre of irrigated land.
The country had experienced a compound growth rate of 2.6 per cent over the
period 1971 – 1972 to 1985-86 under mulberry cultivation (Lakshmana et al., 1989)
16
Sharanyakumar Gowda, Y.K.
similarly, growth rate of production of raw silk and productivity were 4 per cent and 1.6
per cent.
Mohan et al., (1990), opined that, sericulture had turned out to be highly
remunerative cash crop with minimum investment. The value of gross output per acre
with less irrigation was Rs.12000 to Rs.15000 per annum and even more when cocoon
prices ruled high.
Karutagi (1991), reported that, the per hectare maintenance cost of mulberry
garden under irrigation condition in Bijapur district of Karnataka state was Rs. 18043.99.
The operational cost was Rs.10260.58 of which human labour accounted for the highest
proportion (Rs.4000.94) followed by bullock labour (Rs.2349.17) Fertilizer (Rs.2279)
and FYM (Rs.1631.47). The fixed cost were estimated to be Rs. 7783.41. He further
estimated that the average yield of cocoons obtained from a hectcare of mulberry crop in
Bijapur district was 1001.40 kg. The gross returns from the silk cocoon enterprise was
Rs.88961.96 per hectare and this included the value of cocoons (Rs. 84718.44), 20
cartloads of litter (Rs. 1160), 67.64 cartloads of stalks (Rs. 1054.32). The net returns from
cocoon production amounted to Rs.52680.11.
Chandrashekaran and Radha (1991), pointed out that sericulture is an agro- based
cottage industry where the investment is comparatively low with quick and high returns.
They also reported that sericulture could be ideally fitted into the farming system which
boost the economy of the farmers.
Chandra Reddy and Eswar Prasad (1992), examined the technical efficiency of
resources in the production of silk cocoon. They employed frontier production function
with gross revenue from cocoon per farm as the dependent variable and machinery (XI),
maintenance cost of mulberry garden (X2), cost of silkworm cocoon production (X3)
(excluding X1 and X2), wages for labour (X4) and rental value of owned land under
mulberry crop (X5) as independent variable. In general, the farmers used farm resources
at more than the desired level in anticipation of higher return from cocoon production.
The study revealed that 82 per cent of the small and 84 per cent of the large farmers
obtained more than 91 per cent of the desired level of cocoon production.
Yadaiah and Sarangpani (1994), studied the cost and employment generation in
sericulture in sericulture enterprise in Warangal district of Andhra Pradesh. The total
employment generated was about 923.31 man-days and the cost was Rs.13903.27 per
hectare. Sericulture was to be the most beneficial enterprise in such drought prone areas.
Jagannathan (1995), studied the costs and structure and employment generation in
sericulture enterprise in Coimbatore district of Tamil Nadu. The study revealed that the
cost declined with the increase in farm size of the farmer. The cost incurred ranged from
Rs.12000 in the case of marginal farmer to Rs. 10763.63 in the case of big farmers.
Farmer of all categories realized more than 97 per cent of their income only from the sale
of cocoons. Income from sale of leaves and cuttings were nil for small farmer and it
increased along with the farm size. The total cost of labour employment generated ranged
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
17
from 1392.5 man-days in the case of marginal farmers to 1423.63 man-days in the case of
big farmer and big farmer ranged between Rs.13779.63 to Rs.29073.43.
Dodmani (1996), conducted a study in Dharawad district of Karnataka on
economics of silk production. The study revealed that the cocoon yield was 435.24 kg of
good quality cocoon and 9.53 kg of waste cocoon per hectare. The by-product of cocoon
production were litter material manure of 12.45 cartloads. The cocoon yield obtained in
Dharawad district was below the sale of good quality cocoon Rs. 24410.28. The returns
from the sale of by-products was Rs. 784.39 and gross returns was Rs.25194.67.
Lakshmana et al. (1996), reported that the Benefit – Cost ratio for one hectare of
mulberry was high in Dharmapuri (1:1.41) compared to Salem 11:1.30). He suggested
that by allocation of resources on rational basis, higher net returns can be obtained.
Lakshmanan et al. (1997), studied the total cost of mulberry leaf production in
major silk cocoon producing states of south India. In Karnataka it indicated that farmers
had incurred an average of Rs.9580.40 and Rs.11003.45 during 1993-94 and 1995-96
under assured irrigated farm against Rs.4704.15 and Rs.5304.35 under rainfed farm
during the above period. In Andhra Pradesh average cost was worked out to be
Rs.9672.00 and Rs.10574.95 while for Tamil Nadu and Kerala it was Rs. 10336 and
Rs.9854.95, Rs.6144.20, respectively. The cost differed between years and states was due
to increasing price and irrigational use of factors of production in the farm.
Lakshmanan et al. (2000), studied ecomonics of bivoltine vs cross breed cocoon
production in K.R. Nagar taluk of Mysore district. The study revealed that cost of
mulberry leaf production ( per acre per year) was Rs. 11091.55 incurred in producing leaf
for bivoltine rearing and Rs. 10323.60 for cross breed rearing and also opined that the
cost of cocoon production ( per acre per year) in case of bivoltine was Rs.19357.05 and in
cross breed was Rs.18700.27.
Kumaresan and Vijay Prakash (2001), conducted a study on economics of
sericulture vis-à-vis competing crops in erode district of Tamil Nadu. The study revealed
that labour was the chief input in the production of mulberry leaf, which accounted for
Rs. 5917.67 / acre/year. Farm yard manure and fertilizer was the major cost components
in the cultivation of mulberry, which were estimated to leaf production to Rs. 2553.33
and Rs.3283.00 per year, respectively. The total leaf production cost was worked out to
Rs. 14157.40 per acre per annum. The total cost incurred on silkworm rearing was Rs.
40061.40 per acre per year.
Venkateshwara Rao et al. (2001), conducted a study on comparative economics of
cocoon production in coastal area and traditional area of Andhra Pradesh. They found
that the cost of mulberry leaf production in Chittoor and Eluru areas was Rs.10615.81
and Rs.11242.20 respectively. Labour was found to be major input in maintenance of
mulberry garden. The cost of the labour in Chittoor was Rs. 5726.24 per acre per year
and for Eluru, it was Rs. 5726.24 per acre per year. He also worked out the cost
18
Sharanyakumar Gowda, Y.K.
component next to the mulberry leaf production, which amounted to Rs.5063.86 per
acre/year in Chittoor area and Rs.5834.16 in Eluru area.
The comparative economics of production of bivoltines and crossbreeds with
respect to the Benefit – Cost ratio was 1.42 and 1.25, respectively, (Anon., 2002)
Hiriyanna et al. (2002), studied comparative economics of bivoltine and
multivoltine hybrids in cocoon production. They reported that labour was the major input
in production in the production of mulberry leaf amounted to Rs. 8855.75 for CSR hybrid
and Rs. 7966.99 for multivoltine hybrid and CSR hybrid, farmer spent Rs. 5516.65
towards farmyard manure but the expenditure of multi x bivoltine hybrid rearing farmer
towards the organic manure was comparatively less with Rs. 4975.90. The total
operational costs were worked out to be Rs. 21163.11 and Rs. 19111.20 for mulberry
production /acre/year, for CSR hybrid and multi x bivoltine hybrid rearing. Rs. 4475.32
and Rs. 6026. They also opined that cost of production of bivoltine silk in India higher
than imported silk.
Kumaresan et al. (2002), estimated higher net revenue of Rs.3456/- and Benefit –
Cost ratio of 1:1.34 for CSR hybrids compared to cross breeds Rs.1,099/- 1:1.16. for net
revenue and B:C ratio, respectively.
Dandin and Kumaresan (2003), reported profitability of Rs.39883/- per acre per
year at the cocoon price of Rs.120 per kg and yield level of 60kg/100dfls. The profit was
just little more than half with Rs.20158/- when the farmers harvested an average yield of
50kg/100dfls.
Quadir and Dandin (2006), recorded highest cocoon production (977MT) under
1323ha of mulberry in Krishnagiri district of Tamil Nadu followed by Erode (596MT,
750.54ha), Dharmapuri (289MT, 513ha) and Coimbatore (278MT, 447ha).
Balasaraswathi et al. (2005), compared the economics of mulberry and cocoon
productions in Erode and Dharampuri Districts of Tamil Nadu and reported a Benefit –
Cost ratio of 1:1.38 and 1:1.61, respectively.
Hajare et al. (2008), obtained high Benefit – Cost ratio in mulberry sericulture
(1:2.1 to 1:2.2) compared to other crops viz., paddy-sunflower (1:1.7 to 1:2.1), soya bean
– wheat (1:1.7 to 1:2.0) and soya bean – gram (1:1.6 to 1:11.8).
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
19
III MATERIAL AND METHODS
The details of material used and methods adopted during the course of
investigation on “The performance of double cross hybrids of silkworm, Bombyx mori L.,
in central dry zone of Karnataka” is detailed below. The breeds viz., (CSR6 x CSR26) X
(CSR2 x CSR27), (CSR2 x CSR27) X (CSR6 x CSR26), (CSR2 x CSR4) and (PM X
CSR2) were reared on V1 variety of mulberry during 2014. The field survey was
conducted to know the performance of double cross hybrids (CSR6 x CSR26) X (CSR2
x CSR27) compared with (PM X CSR2) at farmers level (Chitradurga District) and
calculated the economics of cocoon production with the help of pre structured interview
schedule.
3.1. Preparation for rearing
The required number of disease free layings (df’ls) of double hybrids viz., DH1
{CSR6 x CSR26) X (CSR6 x CSR27)}, DH2 {CSR2 x CSR27) x (CSR6 x CSR26)} a
bivoltine hybrid (CSR2 x CSR4) and a cross breed (PMxCSR2) were obtained from
National Silkworm Seed Project, Central Silk Board, Bangalore.
3.2 Disinfection of rearing room
Before the commencement of silkworm rearing, the rearing room and appliances
were thoroughly cleaned and the floor was washed using 5 per cent bleaching powder
solution. Then the whole room was disinfected with four per cent formalin at the rate of
1.5ml/m2 Dandin and Giridar (2010) by using rocker sprayer for effective disinfection.
The rearing room was kept air tight for 24 hours. After 24 hours, the room was kept open
and used for rearing.
3.3. Incubation of eggs
The layings procured were incubated in the disinfected rearing trays by adopting
standard incubation and dark treatment practices Dandin and Giridar (2010) to obtain
uniform hatching, silkworm eggs at the blue egg stage were kept in block boxes. One day
prior to hatching, the rearing tray was lined with paraffin paper at the bottom. Wet foam
rubber strips were placed along the edges of rearing tray. Bed was also covered with
paraffin paper at the top to maintain temperature and humidity.
3.4. Brushing and Rearing
Mulberry leaves were cut into small squares of 0.25 cm2 and sprinkled over the
egg cards. The neonate larvae crawled over the tender leaves and started feeding. Later,
cards were tapped into the rearing bed to collect the remaining worms. Another paraffin
sheet was used to cover the bed to maintain required relative humidity and temperature
and to keep the leaves fresh and turgid. The larvae were fed four times a day with suitable
quality leaves Dandin and Giridar (2010).
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
20
Leaves from V1 mulberry variety was used for feeding the larvae. First three
instars were fed four times daily viz., 6am, 11am, 2pm and 6 pm and the fourth and fifth
instar worms were fed 3 times a day at 8 am, 2pm and 6 pm.
Bed cleaning was done once during first, second and third instar and for
subsequent instars, cleaning was done every day.
3.5. Environmental condition during silkworm rearing
During rearing, the mean temperature and relative humidity was recorded.
3.6. Mulberry garden
The V1 mulberry variety grown in red soil with spacing of 90 x 90 cm of the 10
years old plantation was used for the experiment.
3.7. Experiment details
Laboratory experiments were conducted to study the performance of double
hybrids (DH1 and DH2) in comparison with bivoltine hybrid, CSR2 x CSR4 and cross
breed, PM X CSR2 during 2013-2014 in the Department of Sericulture, University of
Agricultural Sciences, GKVK, Bangalore. Economic parameters were recorded for DH1,
DH2, CSR 2 X CSR4 and PM X CSR2 reared on V1 during December(2013)-January
(2014) and March - April(2014).
3.7.1. Performance of double hybrids in comparison with bivoltine hybrid
cross breeds
and
3.7.2 Observations recorded
Design
CRD
No. of treatments
4
No. of replications/treatment
5
No. of worms/ replication
100
Silkworm breeds
(CSR6xCSR26)x(CSR2xCSR27),
(CSR2 xCSR27)x(CSR6xCSR26),
(CSR2x CSR4) and
(PM x CSR2)
21
Sharanyakumar Gowda, Y.K.
Plate1. View of silkworm rearing under laboratory condition
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
22
3.7.2.1 Early larval duration (h)
The time taken by the silkworm from brushing to fourth moult was taken as
chawki duration and expressed in hours.
3.7.2.2 Total larval duration (h)
The time taken by the silkworm from brushing to spinning was taken as total
larval duration and expressed in hours.
3.7.2.3. Early and late instar mature larval weight (g)
Observation on weight of 10 larvae at the beginning of each instar before giving
the first feed were recorded replication wise for each treatment.
3.7.2.4. Effective rate of rearing (%)
Effective rate of rearing (ERR) is the ratio of total number of cocoons formed to
the total number of silkworms brushed. In each replication it was calculated to the
number of worms brushed.
Number of cocoons harvested
ERR = -------------------------------------------- ×100
Number of worms brushed
3.7.2.5. Cocoon yield / 100 larvae (g)
Yield per 100 larvae was calculated by weight.
3.7.2.6. Cocoon yield / 100 dfl’s (kg)
Cocoon Yield per 100 dfl’s was calculated by weight.
3.7.2.7. Single cocoon weight (g)
The cocoons were harvested on sixth day after spinning. In each replication ten
cocoons were selected at random and weighed. Individual cocoon weight was taken for
10 cocoons and average was calculated to compute the mean cocoon weight.
3.7.2.8. Single shell weight (g)
In each replication, ten cocoons were randomly selected and cut opened the pupae
and cast skin were separated and the cocoon shell weight was recorded and average was
calculated to get the mean shell weight.
23
Sharanyakumar Gowda, Y.K.
3.7.2.9. Cocoon shell percentage (%)
It was worked out as follows
Shell weight (g)
Shell percentage = ------------------------------- × 100
Cocoon weight (g)
3.7.2.10. Silk productivity (cg/day)
Silk productivity was calculated using the following formula and expressed as
cg/day Iyengar et al. (1983)
Weight of cocoon shell (cg)
Silk productivity (cg/day) = -------------------------------------------- × 100
Fifth instar duration (days)
3.7.2.11. Silk filament length and filament weight
A sample of ten cocoons per replication was drawn and stifled in hot air oven at
70°C for three hours and then left under shade for three days. The cocoons were cooked
individually in boiling water for four minutes to soften the sericin layer and then reeled
on an “Epprouvette”. Length of the silk filament was determined by the number of
revaluations recorded which was then converted into meter by the formula.
Silk filament length = R X 1.125
R = Number of revolution
1.125 = Circumference of Epprouvette
The silk filament removed from Epprouvette was weighed after conditioning in an
oven at 70° C for four minutes.
3.7.2.12. Denier
Weight of the silk filament (g)
Denier = ---------------------------------------- ×9000
Length of the silk filament (m)
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
24
3.8. Rearing performance of double cross hybrids in comparison with cross breed at
farmers (field) level
3.8.1 Location and Survey
A survey was undertaken sericulturaly predominant taluks in Hiriyur, Challakere
and Molkalmur taluks of Chitradurga district which are under the juridiction of KVK,
Hiriyur, with a sample size of 30, 35, and 35 respondents in each taluk by adopting
personal interview and assertion method on rearing sites.
In addition to survey, rearing was conducted in farmers field level to know the
performance of double cross hybrids DH1 (CSR6 x CSR26) x (CSR2 x CSR27) in
comparison with cross breed PM X CSR2 reared on V1 mulberry from randomly selected
ten farm holdings with farm size of one acre mulberry area during the month of Jan-Feb
(2013-14).
3.8.2. Collection of data
Suitable schedules were developed in Kannada and collected the data to know the
rearing performance of double hybrids of silkworm from 100 farmers of Hiriyur,
Challakere and Molkalmur taluks of Chitradurga district.
The rearing performance of silkworms were collected at the stage of third instars
onwards. Twenty samples were collected from each farm holding for recording the
following economic parameters. viz., larval weight, cocoon weight, shell weight, shell
ratio, silk filament length and silk filament weight. At the same time, information on
mulberry cultivation and rearing of silkworm were also recorded in the data sheet
(Appendix 1).
3.8.3. Rearing parameters were recorded during rearing under farmer field
condition
1. Larval duration (days) for late age
2. Mature larval weight (g)
3. Cocoon yield per 100 dfl’s
4. Cocoon weight (g)
5. Shell weight (g)
6. Shell ratio (%)
7. Silk productivity (cg /day)
25
Sharanyakumar Gowda, Y.K.
8. Filament length (m)
9. Filament weight (g)
10. Denier
3.9. Economics of double cross hybrids
The data was collected to working out the economics of cocoon production from
100 farmers of Chitradurga district during 2013-2014.
3.9.1. Average Leaf yield (kg)
The average leaf yield was recorded in one acre of mulberry garden.
3.9.2. Cost per kg of leaf (Rs.)
The total cost spent for the production of leaf in one acre was recorded and from
that the cost of production of leaf per kg was calculated.
3.9.3. Cost per kg of Cocoon (Rs.)
The total cost of cocoon production was estimated from the cost per kg of cocoon
was arrived.
3.9.4. Average Cocoon yield (kg)
Average cocoon yield (kg) per acre in the farmer field.
3.9.5. Average cocoon price (Rs.)
The cocoon price at nearby market was taken.
3.9.6. Average returns per kg (Rs.)
Average cocoon price got by farmer for their cocoons.
3.9.7. Benefit – Cost ratio
Refers to the average returns per kg divided by the cost per kg of cocoon. It was
arrived using the formula,
Average returns / kg of cocoons
CBR = ------------------------------------------Cost of cocoons / kg
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
26
Plate 2. View of silkworm rearing in farmers house
27
Sharanyakumar Gowda, Y.K.
Plate 3. Data collection from silkworm rearers
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
28
The establishment cost of mulberry garden was considered as fixed cost. The
annual cost was worked out by apportioning the establishment cost for 10 years,
considering the economic life period of mulberry garden as 10 years. The depreciation
was worked out using the traditional straight line method for investments made for
silkworm rearing such as rearing house, silkworm rearing equipments and mountages.
Benefit – cost ratio was then calculated for DH1 and PM × CSR2 reared on mulberry
variety V1.
3.10. Statistical analysis
The experimental data collected on various economic and yield parameters were
subjected to Fisher’s method of analysis of variance (ANOVA) as per methods outlined
by Gomez and Gomez (1984). Critical difference (CD) was calculated wherever the ‘F’
test was found significant. The data are presented with the level of significance at 5 per
cent.
29
Sharanyakumar Gowda, Y.K.
IV EXPERIMENTAL RESULTS
The results of experiment conducted to study the performance of bivoltine double
hybrids of Bombyx mori L. in comparison with bivoltine hybrids CSR2 XCSR4 and multi
x bivoltine cross breed PM X CSR2 are presented here under.
4.1. Assessment of economic and yield parameters of bivoltine double cross hybrids,
bivoltine hybrids and cross breeds of silkworm Bombyx mori L.
The data on economic and yield parameters of four silkworm breeds, viz., DH1
(CSR6 x CSR26) x (CSR2 x CSR27), DH2 (CSR2 x CSR27) x (CSR6 x CSR26), (CSR2
x CSR4) and PM X CSR2 reared on V1 mulberry variety during 2013-2014 are presented
here under.
4.1.1. Early larval duration (h)
The early larval duration varied significantly among different breeds, PM X CSR2
during first rearing recorded lower in I, II and III instars larval duration of 83.49 h, 65.85
h and 114.07 h followed by DH1 (85.67 h, 66.41 h and 117.38 h) and DH2 (85.67h,
66.42 h and 117.66 h). However, highest larval duration was recorded in CSR2 XCSR4
(85.80 h, 66.94 h and 118.25 h) (Table 1).
Similar trend was also observed during second rearing breeds. The PM X CSR2
had recorded lower larval duration in I, II and III instars (83.47 h, 65.54 h and 113.72)
followed by DH1 (85.63 h, 66.37 h and 116.46 h) and DH2 (85.63 h, 66.37 h and 116.46
h). The longest larval duration was recorded in CSR2 XCSR4 (85.77 h, 66.87 h and
119.96 h) (Table 2).
4.1.2. Fourth and fifth instar larval duration (h)
The fourth and fifth instar larval duration varied significantly among different
hybrids. The cross breed of PM X CSR2 during first rearing recorded lower, fifth instar
larval duration was 150.02 h and 176.57 h followed by DH1 (155.49 h and 193.43 h) and
DH2 (155.44 h and 193.44 h) in first rearing. The longest fourth and fifth instar larval
duration was recorded in CSR2 XCSR4 (156.04 h and 193.75 h) (Table 1).
Similarly, the breed PM X CSR2 performed better during second rearing recorded
lower fourth and fifth instar larval duration of 149.48 and 172.93h followed by DH1
(151.35 and 191.21 h) and DH2 (151.34 and 191.20 h). The highest larval duration was
recorded in CSR2 XCSR4 (151.92 and 191.83 h) (Table 2).
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
27
28
Sharanyakumar Gowda, Y.K.
Fig. 1: First instar larval duration in different hybrids of silkworm,
Bombyx mori L.
Fig. 2: Second instar larval duration in different hybrids of silkworm,
Bombyx mori L.
T1: (CSR6 x CSR26) x (CSR2 x CSR27) T3: (CSR2 X CSR4)
T2: (CSR2 x CSR27) x (CSR2 x CSR26) T4: (PM X CSR2)
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
29
Fig. 3: Third instar larval duration in hybrids of silkworm,
Bombyx mori L.
Fig. 4: Fourth instar larval duration in different hybrids of silkworm,
Bombyx mori L.
T1: (CSR6 x CSR26) x (CSR2 x CSR27) T3: (CSR2 X CSR4)
T2: (CSR2 x CSR27) x (CSR2 x CSR26) T4: (PM X CSR2)
30
Sharanyakumar Gowda, Y.K.
Fig. 5: Fifth instar larval duration in different hybrids of silkworm,
Bombyx mori L.
Fig. 6: Total larval duration in different hybrids of silkworm,
Bombyx mori L.
T1: (CSR6 x CSR26) x (CSR2 x CSR27) T3: (CSR2 X CSR4)
T2: (CSR2 x CSR27) x (CSR2 x CSR26) T4: (PM X CSR2)
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
31
32
Sharanyakumar Gowda, Y.K.
4.1.3. Total larval duration (h)
There was significant variation in the total larval duration due to breeds, PM X
CSR2 performed well during first rearing recorded lower total larval duration of 599.7 h
followed by DH1 (613.7 h) and DH2 (613.7 h). The highest total larval duration was
recorded in CSR2 XCSR4 (613.8 h) (Table 1).
Among different breeds, PM X CSR2 performed better in second rearing with
lower total larval duration of 586.14h followed by DH1 (611.04 h) and DH2 (611.03 h).
The highest total larval duration was recorded in CSR2 X CSR4 (612.03 h) (Table 2).
4.1.4. Early larval weight (g)
The early larval weight varied significantly among different breeds. The hybrids
DH1 performed well during first rearing with maximum I, II and III instars larval weight
of (0.061g, 0.318g and 2.122 g), followed by DH2 (0.060g, 0.315g and 2.120g). The
lowest larval weight was recorded in PM X CSR2 (0.056g, 0.291g and 1.909) (Table 3).
Even during second rearing the breed, DH1 performed well recorded maximum I,
II and III instars larval weight (0.060g, 0.316 g and 2.119g) followed by DH2 (0.060g,
0.313g and 2.118g). The lowest larval weight was recorded in PM X CSR2 (0.056 g,
0.288 g and 1.899 g) (Table 4).
4.1.5. IV and V instar larval weight (g)
Significantly highest IV and V instar larval weight of irrespective of the breeds,
DH1 performed well during first rearing which recorded maximum larval weight of
(8.523g and 43.33g/10 larvae) followed by DH2 (8.517g and 43.17g/10 larvae). The
lowest IV and V instar larval weight was recorded in PM X CSR2 (7.794g and 33.83g/10
larvae) (Table 3).
Similar trend was observed in, DH1 performed well during second rearing with
maximum IV and V instar larval weight of (8.539g and 42.278g/10 larvae) followed by
DH2 (8.417g and 42.27g/10 larvae). The lowest IV and V instar larval weight was
recorded in PM X CSR2 (31.31g and 31.31g/10 larvae) (Table 4).
4.1.6. Effective rate of rearing (ERR)
The ERR recorded among different breeds were non-significant. However, the
hybrids DH1 and DH2 recorded more ERR (98.20 % and 98.00 % ) where as the ERR
recorded was lowest in the silkworm hybrid CSR2 X CSR4 (97.80 %) (Table 7).
Similarly, during second rearing the breeds, PM X CSR2 recorded highest ERR
(98.0 %) followed by DH1 (97.6 %) and DH2 (97.4 %). The lowest ERR was recorded in
CSR2 X CSR4 (97.2 %). There was no significant difference between the breeds in terms
of ERR (Table 8).
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
33
Table 3: Larval parameters in different hybrids of silkworm, Bombyx mori L. in
different instar (First rearing)
Larval weight (g/10 worms)
Hybrids
I Instar
II
Instar
III
Instar
IV
Instar
V
Instar
T1:(CSR6 x CSR26) x (CSR2 x CSR27)
0.061
0.318
2.122
8.523
43.33
T2:(CSR2 x CSR27) x (CSR2 x CSR26)
0.060
0.315
2.120
8.517
43.17
T3:(CSR2 X CSR4)
0.059
0.310
2.119
8.170
37.38
T4:(PM X CSR2)
0.056
0.291
1.909
7.794
33.83
F-test
*
*
*
*
*
SEm ±
0.00064
0.0016
0.0137
0.0435
0.234
C D @ 5%
0.0019
0.0048
0.0413
0.1306
0.702
Table 4: Larval parameters in different hybrids of silkworm, Bombyx mori L. in
different instar (Second rearing)
Larval weight (g/10worms)
Hybrids
I
Instar
II
Instar
III
Instar
IV
Instar
V
Instar
T1:(CSR6 x CSR26) x (CSR2 x CSR27)
0.060
0.316
2.119
8.539
42.27
T2:(CSR2 x CSR27) x (CSR2 x CSR26)
0.060
0.313
2.118
8.417
42.27
T3:(CSR2 x CSR4)
0.058
0.309
2.117
8.150
36.76
T4:(PM x CSR2)
0.056
0.288
1.899
7.76
31.31
F-test
*
*
*
*
*
SEm ±
0.0006
0.0019
0.0123
0.056
0.103
C D @ 5%
0.0019
0.005
0.037
0.168
0.309
34
Sharanyakumar Gowda, Y.K.
4.1.7. Cocoon yield per 100 larvae (g)
There was significant variation in the yield per 100 larvae among different breeds.
Both DH1 and DH2 performed well during first rearing with highest yield per 100 larvae
(199.23g) and (199.71g) If followed by CSR2 X CSR4 (179.40g). The lowest yield per
100 larvae recorded in PM X CSR2 (154.99g) (Table 5).
The yield per 100 larvae varied significantly among different breeds. Both DH1
and DH2 performed well during second rearing with highest yield per 100 larvae
(197.80g) and (197.70g) If followed by CSR2 X CSR4 (176.90g). The lowest yield per
100 larvae recorded in PM X CSR2 (151.60g) (Table 6).
4.1.8. Cocoon yield per 100 dfl’s (kg)
Significantly more cocoon yield per 100 dfls was recorded in DH1 78.53 kg
followed by DH2 78.45 kg and CSR2 X CSR4 (73.48 kg/100dfls). The low cocoon yield
per 100 dfls was recorded in PM X CSR2 (68.89kg) during first rearing (Table 5).
Even during second rearing both the breeds, DH1 and DH2 performed well
with highest yield per 100 dfls (75.50kg) and (75.50kg) followed by CSR2 X CSR4
(70.20 kg). The lowest yield per 100 dfls was recorded in PM X CSR2 (64.90kg) (Table
6).
Table 5: Yield parameters in different hybrids of silkworm, Bombyx mori L.
(First rearing)
Hybrids
Cocoon yield/ 100
larvae(g)
Cocoon yield /100
Dfl’s (kg)
T1:(CSR6 x CSR26) x (CSR2 xCSR27)
199.23
78.53
T2:(CSR2 x CSR27) x (CSR2 xCSR26)
199.71
78.45
T3:(CSR2 X CSR4)
179.40
73.48
T4:(PM X CSR2)
154.99
68.89
F-test
*
*
SEm ±
0.455
0.217
C D @ 5%
1.364
0.651
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
35
Fig. 7: First instar larval weight in different hybrids of silkworm,
Bombyx mori L.
Fig. 8: Second instar larval weight in different hybrids of silkworm,
Bombyx mori L.
T1: (CSR6 x CSR26) x (CSR2 x CSR27) T3: (CSR2 X CSR4)
T2: (CSR2 x CSR27) x (CSR2 x CSR26) T4: (PM X CSR2)
36
Sharanyakumar Gowda, Y.K.
Fig. 9: Third instar larval weight in different hybrids of silkworm,
Bombyx mori L.
Fig. 10: Fourth instar larval weight in different hybrids of silkworm,
Bombyx mori L.
T1: (CSR6 x CSR26) x (CSR2 x CSR27) T3: (CSR2 X CSR4)
T2: (CSR2 x CSR27) x (CSR2 x CSR26) T4: (PM X CSR2)
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
37
Fig. 11: Fifth instar larval weight in different hybrids of silkworm,
Bombyx mori L.
Fig. 12: Effective rate of rearing in different hybrids of silkworm,
Bombyx mori L.
T1: (CSR6 x CSR26) x (CSR2 x CSR27) T3: (CSR2 X CSR4)
T2: (CSR2 x CSR27) x (CSR2 x CSR26) T4: (PM X CSR2)
38
Sharanyakumar Gowda, Y.K.
(CSR6 x CSR 26) X (CSR 2 x CSR 27)
(CSR2 X CSR 4)
(CSR 2 x CSR 27) x (CSR 2 x CSR 26)
(PM X CSR2)
Plate 4. Fifth instar silkworm of different hybrids
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
39
Table 6: Yield parameters in different hybrids of silkworm, Bombyx mori L.
(Second rearing)
Hybrids
Cocoon weight/100
larvae (g)
Cocoon yield
/100 Dfl’s (kg)
T1:(CSR6 x CSR26) x (CSR2 x CSR27)
197.80
75.50
T2:(CSR2 x CSR27) x (CSR2 x CSR26)
197.70
75.50
T3:(CSR2 X CSR4)
176.90
70.20
T4:(PM X CSR2)
151.60
64.90
F-test
*
*
SEm ±
0.28
0.13
C D @ 5%
0.84
0.39
4.1.9. Single cocoon weight (g)
The single cocoon weight was found significantly among different breeds, DH1
and DH2 performed well during first rearing which recorded highest cocoon weight
2.07g and 2.04g, respectively followed by CSR2 X CSR4 (1.85 g). The lowest cocoon
weight was recorded in PM X CSR2 (1.74g) (Table 7).
DH1 and DH2 breeds performed significantly better during second rearing which
recorded highest cocoon weight 2.04g and 2.03g followed by CSR2 X CSR4 (1.82g). The
lowest cocoon weight was recorded in PM X CSR2 (1.72g) (Table 8).
4.1.10. Single shell weight (g)
The cocoon obtained from the silkworm breeds DH1 recorded significantly higher
shell weight 0.488g followed by DH2 0.480g. The lowest shell weight was recorded in
PM X CSR2 (0.330g) (Table 7).
Even during second rearing the breed, DH1 recorded higher shell weight (0.476g)
followed by DH2 (0.472g). The lowest shell weight (0.330g) was recorded in PM X
CSR2 (Table 8).
40
Sharanyakumar Gowda, Y.K.
Table 7: Economic parameters in different hybrids of silkworm, Bombyx mori L.
(First rearing)
ERR
(%)
Cocoon
weight
(g)
Shell
weight
(g)
Shell
Ratio
(%)
T1:(CSR6 x CSR26) x (CSR2 x CSR27)
98.20
2.07
0.488
23.57
T2:(CSR2 x CSR27) x (CSR2 x CSR26)
98.00
2.04
0.480
23.52
T3:(CSR2 X CSR4)
97.80
1.85
0.432
23.35
T4:(PM X CSR2)
98.50
1.74
0.330
18.98
F-test
NS
*
*
*
SEm ±
0.367
0.0102
0.0040
0.0093
C D @ 5%
1.101
0.030
0.0120
0.0278
Hybrids
Table 8: Economic parameters of different hybrids of silkworm, Bombyx mori L.
(Second rearing)
ERR
(%)
Cocoon
weight
(g)
Shell
weight
(g)
Shell
Ratio
(%)
T1:(CSR6 x CSR26) x (CSR2 x CSR27)
97.60
2.04
0.476
23.33
T2:(CSR2 x CSR27) x (CSR2 x CSR26)
97.40
2.03
0.472
23.25
T3:(CSR2 x CSR4)
97.20
1.82
0.422
23.18
T4:(PM x CSR2)
98.00
1.72
0.33
19.18
F-test
NS
*
*
*
SEm ±
0.339
0.0069
0.00509
0.0112
C D @ 5%
1.016
0.020
0.0152
0.0338
Hybrids
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
41
Fig. 13: Cocoon weight in different hybrids of silkworm,
Bombyx mori L.
Fig. 14: Shell weight in different hybrids of silkworm,
Bombyx mori L.
T1: (CSR6 x CSR26) x (CSR2 x CSR27) T3: (CSR2 X CSR4)
T2: (CSR2 x CSR27) x (CSR2 x CSR26) T4: (PM X CSR2)
42
Sharanyakumar Gowda, Y.K.
Fig. 15: Shell ratio in different hybrids of silkworm,
Bombyx mori L.
Fig. 16: Silk productivity in different hybrids of silkworm,
Bombyx mori L.
T1: (CSR6 x CSR26) x (CSR2 x CSR27) T3: (CSR2 X CSR4)
T2: (CSR2 x CSR27) x (CSR2 x CSR26) T4: (PM X CSR2)
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
43
(CSR6 x CSR 26) X (CSR 2 x CSR 27) (CSR 2 x CSR 27) x (CSR 2 x CSR 26)
(CSR2 X CSR 4)
(PM X CSR2)
Plate 5. Cocoons of different silkworm hybrids
44
Sharanyakumar Gowda, Y.K.
4.1.11. Shell ratio (%)
There was significant variation in the shell ratio among the breeds, the DH1 breed
performed better during first rearing which recorded highest shell ratio (23.57 per cent)
followed by DH2 (23.52 per cent). The lowest shell ratio was recorded in PM X CSR2
(18.98 per cent) (Table 7).
Similarly the breed, DH1 performed better during second rearing with maximum
shell ratio of 23.33 per cent followed by DH1 (23.25 per cent). The lowest shell ratio was
recorded in PM X CSR2 (19.18 per cent) (Table 8).
4.1.12. Silk productivity (cg/day)
There was significant variation in the silk productivity due to different breeds.
The hybrid DH1 performed well during first rearing which recorded highest silk
productivity (5.99cg/day) followed by DH2 (5.95cg/day). The lowest 4.43 cg/day silk
productivity was recorded in PM X CSR2 (Table 9).
Even during second rearing the breed, DH1 recorded highest silk productivity of
(6.01cg/day) followed by DH2 (5.89cg/day). The lowest silk productivity was recorded in
PM X CSR2 (4.58cg/day) (Table 10).
4.1.13. Filament length (m)
The filament length was found significantly among different breeds, DH1
performed better during first rearing which recorded highest filament length 1249.2m
followed by DH2 (1246.8m). The lowest filament length was recorded in PM X CSR2
(989.20m) (Table 9).
Similarly the breed, DH1 performed better during second rearing with highest
filament length 1237.1m followed by DH2 (1233.6m). The lowest filament length
(982.63m) was recorded in PM X CSR2 (Table 10).
4.1.14. Filament weight (g)
There was significant variation in the filament weight among different breeds, PM
X CSR2 during first rearing recorded lowest filament weight (0.320g) followed by DH1
(0.370g). The highest filament weight was recorded in CSR2 X CSR4 (0.380g) (Table 9).
Even during second rearing significantly lowest filament weight was recorded in
PM x CSR2 0.312g followed by DH1 (0.362g). The highest filament weight was
recorded in CSR2 X CSR4 (0.370g) (Table 10).
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
45
Table 9: Post cocoon parameters in different hybrids of silkworm, Bombyx mori L.
(First rearing)
Silk
Filament
productivity
length
(m)
(cg/day)
Hybrids
Filamen
t weight
(m)
Denier
T1:(CSR6 x CSR26) x (CSR2 xCSR27)
5.99
1249.2
0.370
2.66
T2:(CSR2 x CSR27) x (CSR2 xCSR26)
5.95
1246.8
0.372
2.68
T3:(CSR2 X CSR4)
5.35
1217.4
0.38
2.80
T4:(PM X CSR2)
4.43
989.20
0.32
2.91
F-test
*
*
*
*
SEm ±
0.097
1.3049
0.0055
0.0132
C D @ 5%
0.290
3.912
0.0166
0.0397
Table 10: Post cocoon parameters in different hybrids of silkworm, Bombyx mori L.
(Second rearing)
Silk
productivity
Filament
length
Filament
weight
(cg/day)
(m)
(g)
T1:(CSR6 x CSR26) x (CSR2 x CSR27)
6.01
1237.1
0.362
2.63
T2:(CSR2 x CSR27) x (CSR2 x CSR26)
5.89
1233.6
0.360
2.62
T3:(CSR2 x CSR4)
5.36
1208.2
0.370
2.75
T4:(PM x CSR2)
4.58
982.63
0.312
2.82
F-test
5.46
1165.4
0.351
2.70
SEm ±
*
*
*
*
0.0378
18.332
0.0155
0.111
Hybrids
C D @ 5%
46
Denier
Sharanyakumar Gowda, Y.K.
Fig. 17: Filament length of different hybrids of silkworm,
Bombyx mori L.
Fig. 18: Filament weight of different hybrids of silkworm,
Bombyx mori L.
T1: (CSR6 x CSR26) x (CSR2 x CSR27) T3: (CSR2 X CSR4)
T2: (CSR2 x CSR27) x (CSR2 x CSR26) T4: (PM X CSR2)
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
47
Fig. 19: Denier of different hybrids of silkworm,
Bombyx mori L.
Fig. 20: Cocoon yield of different hybrids of silkworm,
Bombyx mori L.
T1: (CSR6 x CSR26) x (CSR2 x CSR27) T3: (CSR2 X CSR4)
T2: (CSR2 x CSR27) x (CSR2 x CSR26) T4: (PM X CSR2)
48
Sharanyakumar Gowda, Y.K.
4.1.15. Denier
The denier varied significantly among different breeds, both DH1 and DH2
performed better during first rearing which recorded lowest denier 2.66 and 2.6 followed
by CSR2 X CSR4 (2.80). The highest denier recorded in PM X CSR2 (2.91) (Table 9).
Similarly, the breeds both DH1 and DH2 performed better during second rearing
with lowest denier 2.63 and 2.62 followed by CSR2 X CSR4 (2.75). The highest denier
recorded in PM X CSR2 (2.82) (Table 10).
4.2.1. The data recorded on economic and yield parameters in farmers field level
The data of economic and yield parameters of two silkworm hybrids, viz., DH1
(CSR6 x CSR26) x (CSR2 x CSR27) and PM X CSR2 on V1 mulberry variety during
2013-2014 are presented here under
4.2.2. Larval duration (hours) for late age
Among different breeds, PM X CSR2 was recorded lower fifth instar larval
duration (176.5 h). However, the larval duration recorded was more (193.5h) in (CSR6 x
CSR26) x (CSR2 x CSR27) in farmer field condition (Table 11).
4.2.3. Mature larval weight (g)
The maximum mature larval weight was recorded in the batches of silkworm hybrid
DH1 (38.91g/10 larvae) and the lowest weight 33.05g/10 larvae was recorded in PM X
CSR2 (Table 11).
4.2.4. Yield per 100 dfls (kg)
The yield per 100 dfls was high (75.60 kg) in DH1 followed by PM X CSR2
(64.50 kg/100 dfl’s) (Table 11).
4.2.5. Cocoon weight (g)
The single cocoon weight recorded was maximum (1.96g) in DH1 silkworm breed.
The lowest cocoon weight was recorded in PM X CSR2 (1.73g).
4.2.6. Shell weight (g)
Among different breeds, DH1 performed well during rearing with maximum shell
weight of (0.42g). The lowest shell weight was recorded in PM X CSR2 (0.32g) (Table
11).
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
49
Table 11: Economic parameters in double cross hybrid of silkworm, Bombyx mori
L. in farmers field level.
Hybrids
Fifth
instar
larval
duration
(h)
Mature
10
Larval
weight
(g)
Cocoon
yield/100
Dfl’s
(kg)
Cocoon
weight
(g)
Shell
weight
(g)
Shell
Ratio
(%)
193.5
38.9125
75.6
1.968
0.429
21.841
176.5
33.052
64.5
1.735
0.32
18.6125
(CSR6 x CSR26) x
(CSR2 xCSR27
(PM x CSR2)
Data represents the mean of 10 replications
4.2.7. Shell ratio (%)
The shell ratio differs among different breeds, DH1 performed well during rearing
with maximum shell ratio of (21.84%). The lowest shell ratio was recorded in PM X
CSR2 (18.68%) (Table 11).
4.2.8. Filament length (m)
Among different breeds, DH1 recorded highest filament length 1174.17m. The
lowest filament length was recorded in PM X CSR2 (927.97 m) (Table 12).
4.2.9. Filament weight (g)
The filament weight differed among different breeds. The hybrid DH1 recorded
highest filament weight of 0.34g. The lowest filament weight was recorded in PM X
CSR2 (0.29g) (Table 12).
4.2.10. Denier
The silk productivity among different breeds was difference each other. The
hybrid DH1 recorded with lowest denier 2.65. The highest denier was observed in PM X
CSR2 (2.80) (Table 12).
50
Sharanyakumar Gowda, Y.K.
Table 12: Post cocoon parameters in double cross hybrid of silkworm, Bombyx mori
L. in farmers field level.
Hybrids
Filament
length (m)
Filament
weight (g)
Denier
(CSR6 x CSR26) x (CSR2 x CSR27
1174.175
0.3455
2.655
(PM x CSR2)
927.975
0.2925
2.805
Data represents the mean of 10 replications.
4.3. Economics of cocoon production
Data on estimated economics of cocoon production is furnished in Table 13
The highest average leaf production was recorded in V1 (22,620 kg) and the cost
of leaf production per kg was recorded in V1 (Rs.1.65)
Cost per kg of cocoon was lowest in PM x CSR2 (163.25 Rs/kg) followed by
DH1 (164.34 Rs/kg) on V1 mulberry variety. The cost of cocoon production was higher
in CSR2 XCSR4 (164.48 Rs/kg).
Average cocoon yield per acre was highest in DH1 (183.0 kg/crop/acre) followed
by CSR2 XCSR4 (177.0 kg/crop/acre). The lowest yield was recorded in PM XCSR2
(161.25kg).
The average cocoon price per kg was highest in DH1 (Rs.443.50) and CSR2 X
CSR4 (Rs.438.50). The lowest cocoon price was given to PM X CSR2 (Rs 392.00).
The highest average returns per kg was obtained in DH1 (Rs.444.50) followed by
CSR2 XCSR4 (Rs.439.50). Lesser return was recorded in PM X CSR2 (Rs 393.00).
The highest Benefit-Cost ratio was recorded in DH1 (1:2.70) followed by CSR2
X CSR4 (1:2.59). The lowest B:C ratio of (1:2.40) was obtained in PM X CSR2.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
51
Table 13: Economics of cocoon production for hybrids of silkworm, Bombyx mori L.
at farmers level
Particulars
Hybrids
(CSR6XCSR26)
CSR2XCSR4
PMXCSR2
X(CSR2XCSR27)
Average leaf production
(Kg/acre/annum)
22620
22620
22620
Cost per kg of leaf (Rs.)
1.65
1.65
1.65
Cost per kg of cocoon (Rs.)
164.34
164.48
163.25
Average cocoon
yield(kg/crop/acre)
183.0
177.6
161.25
Average cocoon price (Rs.)
443.50
438.50
392.00
250
250
250
Average returns per kg (Rs.)
444.50
439.50
393.00
Net return per crop
81343.5
78055.2
63371.25
Net return per year (Five
crop)
406717.5
390276
316856.25
1:2.70
1:2.59
1:2.40
Average DFLs brushed /
crop/acre
Cost – benefit ratio
Size of farm holding = 1 acre
Data represent the mean 10 replications
52
Sharanyakumar Gowda, Y.K.
Fig. 21: Benefit-Cost ratio of different hybrids of silkworm,
Bombyx mori L.
T1: (CSR6 x CSR26) x (CSR2 x CSR27) T3: (PM X CSR2)
T2: (CSR2 X CSR4)
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
53
V DISCUSSION
Sericulture occupies a unique place in India’s economy because of its dual role of
income and employment generation. Breakthrough in sericulture can be achieved by the
introduction of new silkworm breeds, high yielding mulberry varieties and adoption of
improved crop production and crop protection technologies. The need of the hour is to
increase the cocoon and silk productivity by reducing the production costs without
affecting the quality of yarn and fabric. In this respect, silkworm breeds play vital role.
Newer breeds slowly replace the existing breeds. The introduction of the hybrids, CSR2
X CSR4 during 1997 has revolutionized the Indian sericulture industry in the production
of quality silk. Even though, the hybrid had the potential to give more yield, it was not
possible to obtain high egg recovery from its parents (P1 cocoons) and this draw back can
be overcome using double hybrids obtained from the foundation crosses. Realizing this
advantage, sericulturally advanced countries such as Japan, China and Brazil have
successfully exploited the double cross hybrids commercially. The suitability of double
cross hybrids have been reported by several authors (Nirmal Kumar et al. 1998),
Naseema Begum et al. (2005) and Dandin et al. (2005). In order to test its suitability for
Central Dry Zone of Karnataka, the investigations were carried out at Department of
Sericulture, University of Agricultural Sciences, Bangaluru and Krishi Vigyana Kendra,
Hiriyur at Chitradurga District. The results obtained are discussed here under.
5.1. Economic and yield parameters of different hybrids of silkworm, Bombyx mori
L.
5.1.1. Larval duration (h)
The larval duration is considered as very important character by sericulture
farmers since the reduction in larval duration minimizes the quantum of total food
consumption without affecting the cocoon yield.
Both the double cross hybrids recorded the lowest larval duration than the
control bivoltine hybrid, CSR2 X CSR4 (Fig 1-6). Similar finding was observed by
Chandrashekar (2003) this might be due to the fact that mulberry shoots were found
maintain turgidity, contributing to the enhanced acceptability and palatability of leaves
leading to increase feeding efficiency of silkworm. Similar trend in double cross hybrid,
(CSR2 X CSR27) X (CSR6 X CSR26) and Chinese double cross hybrids was reported by
Naseema Begam et al. (2005). The present finding also revealed that PM X CSR2 was
significantly superior than double cross hybrids and CSR2 X CSR4. PM X CSR2
completed spinning 19 and 20 h. in advance than double cross hybrids and CSR2
XCSR4, respectively.
5.1.2. Larval weight (g)
The results on larval weight of different breeds revealed that double cross hybrids,
DH1 and DH2 registered higher larval weight than CSR2 X CSR4 and PM X CSR2 (Fig
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
41
7-11).This variation in chawki weight in different hybrids could be attributed to the
genetic makeup of the hybrids. The present result corroborates with the finding of
Govindan et al. (1990) who reported that larval weight was highest in double cross
hybrids than single cross hybrids. It may also attributed due to better ECI in double cross
hybrid followed by PM x CSR2 on V1 mulberry variety Trivedy and Nair (1999).
5.1.3. Effective rate of rearing (ERR)
ERR is an important physiological criterion for selecting superior silkworm
hybrids reported by Trivedy and Nair (1999). ERR has direct impact on the ultimate
cocoon yield.
DH1 and DH2 next best to PM X CSR2 with respect to ERR. The CSR2 X CSR4
ranked least (Fig 12). Similarly, the better performance of double cross hybrids over
single cross hybrids was also by Yokoyama (1973).
The silkworm hybrid CSR2 XCSR4 recorded lesser ERR. This might be due to
higher larval mortality in bivoltines due to the adverse conditions (Datta, 2003).
In the present study, PM X CSR2 performed better than double cross hybrids and
CSR2 X CSR4 which was supported by the reports of Mahadevappa (1998). This might
be due to different in the environmental conditions during rearing.
5.1.4. Cocoon yield/100 larvae
The cocoon yield/100 larvae was more in hybrids DH1 and DH2 than CSR2 X
CSR4 and PM X CSR2 also reported higher yield/100 larvae in double cross hybrids than
single cross hybrids .
The cocoon yield per 100 larvae in double cross hybrids might due to enhanced
growth and developmental characters of larvae in these hybrids which resulted in more
cocoon weight. These findings are in line with that of Nirmal Kumar et al. (1999) who
reported higher cocoon yield/100 larvae in double cross hybrids than cross single hybrids
5.1.5. Cocoon yield/100 dfls
The cocoon yield/100 dfl’s was more in hybrids DH1 and DH2 than CSR2
XCSR4 and PM X CSR2 also reported higher yield/100 dfl’s in double cross hybrids than
single cross hybrids (Fig.20).
The hybrids DH1 and DH2 recorded significantly higher yield compared with
breeds CSR2 X CSR4 and PM X CSR2. This might be due to better larval growth
parameter and more yield of cocoons/100 larvae. This finding is strengthened by the
reports of (Manimegalai and Aruna 2010a). The double hybrids reported that they are
stable in the performance with an average yield of more than 70 kg per 100 dfls, Joge et
42
Sharanyakumar Gowda, Y.K.
al. (2003) it could be conversion of leaf to cocoon is good in double cross hybrid as
evidenced by lower LCR.
5.1.6. Cocoon weight (g)
It is evident from the result that the highest cocoon weight was recorded in double
cross hybrids i.e. DH1 and DH2 than check breeds (Fig 13). The result in on
conformation with this finding of Nirmal Kumar et al. (1999). reported the highest
cocoon weight in DH1 than single hybrids. The present result was further substantiated
with the result of Dayananda et al. (2011), who reported maximum cocoon weight in
double cross hybrids than single cross hybrids. This could be due to tolerance of double
cross hybrids against adverse climatic condition which resulted in the expression of
productive traits
5.1.7. Shell weight (g)
More shell weight was recorded in DH1 and DH2 than CSR2 XCSR4. Similar
trend was reported earlier by Nirmal Kumar et al. (1999) for double cross hybrids. The
present result also agrees with Sohn and Ramirez (1999) who reported that double cross
hybrids showed higher weight of cocoon and cocoon shell compared to the single and
three-way crosses.
The cocoon obtained from the hybrids PM XCSR2 registered lesser shell weight
than double cross hybrids and CSR2 XCSR4 (Fig 14). This was supported by Zita et al.
(2003) who also reported lesser shell weight in PM X CSR2.
5.1.8. Shell ratio (%)
DH1, DH2 and CSR2 X CSR4 on par with respect to shell ratio. Though, the
double cross hybrids showed higher cocoon and shell weight than CSR2 X CSR4,
significant difference was observed regarding shell ratio (Fig 15). This is in agreement
with findings of Sohn and Ramirez (1999) who reported no significant different in shell
ratio between single hybrids and double cross hybrids. Similarly, Mal Reddy et al.,
(1998) reported that more than 23 per cent shell ratio was recorded in double cross
hybrids.
5.1.9. Silk productivity (cg/day)
Silk productivity is the quantum of silk produced by silkworm per day during fifth
instar. Other than genetic control, this property is influenced to a greater extent by other
factors such as rearing environment, quantity and quality of food. It is considered as one
of the breeding index to evaluate silkworm breeds and their single, double and three way
hybrids (Iyengar et al., 1983; Udupa and Visweswara Gowda 1988).
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
43
In the present study, highest silk productivity was estimated in DH1 and DH2 (Fig
16). These results fall in line with finding of Narayana Swamy (1988) who reported
higher silk productivity in double cross hybrids over pure races and single cross hybrids.
5.1.10. Filament length (m)
The main objective of any silkworm breeding programme is to achieve superior
quality of silk as evidenced by longer filament.
In the present investigation, longer filament were recorded in cocoons obtained
from both DH1 and DH2 followed by CSR2 XCSR4. The cocoons from PM X CSR2
recorded the lowest filament length and (Fig 17). The present result fall in line with
Babulal et al. (2005) who reported that bivoltine hybrids recorded longer filament length
than cross breeds. Similarly, Mal Reddy (2003) recorded more filament length and fine
denier in double cross hybrids. Though the denier in DH1 and DH2 is lower, the
degumming loss is very low (Kamajyo et al., 1985)
5.1.11. Filament weight (g) and denier
The lowest filament weight and high denier was observed in CSR2 XCSR4
followed by double cross hybrids (Fig.18-19).
The findings Manimegalai and Aruna (2010b), revealed that the lowest filament
weight and higher denier was registered in the cocoons obtained from multi x bivoltine
hybrids. However, generally the bivoltines produces cocoons with finer filament weight
and finer denier than cross breeds (Krishna Kumar 2001; Dayananda et al., 2011).
5.2. Economic and yield parameters of double cross hybrids of silkworm, Bombyx
mori L. in farmers field level.
The present investigation of all the characters like, single larval weight, late larval
duration, cocoon weight, shell weight, shell ratio, filament length, filament weight, denier
and yield/100 dfl’s from double cross hybrids were showed their superior than cross
breed under field condition. Similar trend was also recorded in the studies conducted by
Manimegalai and Aruna (2010a) and Narayanaswamy (1988) who reported that the
performance of the double cross hybrids shows superiority in cocoon and post cocoon
parameters than cross breeds under field condition, suggested that the better
acclimatization capacity of cocoons derived from double cross hybrids across the climatic
conditions.
5.3. Economics of cocoon production
Average leaf production was highest in V1 variety of mulberry. These results are
in agreement with findings of Dandin and Kumaresan (2003) who reported that V1 has
yield potential of more than 60,000 kg/ha/year. It was observed that those new garden
and are going to establish the garden shown in the interest of V1 variety.
44
Sharanyakumar Gowda, Y.K.
Cost per kg of leaf was higher in V1 variety of mulberry. It may be because of the
fact that V1 requires more quantity of fertilizer than other varieties. With respect to
breeds, cost per kg of cocoon was less in PM X CSR2 than bivoltine and double cross
hybrids because bivoltine hybrid and double cross hybrids require more care and hygiene
during rearing than cross breeds. Moreover, bivoltine hybrids are more susceptible to
diseases than cross breeds.
Average cocoon yield was higher in both DH1 and CSR2 X CSR4. These results
are in agreement with Dandin and Basavaraja (2005) who recorded more than 75 kg/100
dfls from double cross hybrid and CSR2 XCSR4
DH1 and CSR2 X CSR4 fetches higher price per kg of cocoon than PM X CSR2.
The fluctuation in cocoon price is directly dependent upon the returns. In cocoon market,
price finding is done based on the quality of cocoons. DHI and CSR2 X CSR4 cocoons
fetches better price because of good quality. Present results are in agreement with the
findings of Kumaresan and Vijay Prakash (2001), who reported that the average price
realized for CSR hybrids was higher due to good quality of cocoons compared to cross
breed.
More returns per kg revealed from the cocoons of DH1 silkworm batches reared
on V1 followed by the batches of CSR2 X CSR4 on V1. This may be due to the fact that
both quality and biomass was better in V1 Dandin and Kumaresan (2003). These results
are also in conformity with that of Dandin and Basavaraja (2005).
The highest Benefit – Cost ratio on V1 was registered with silkworm hybrid DH1
(Fig 21). It may be due to higher returns, good quality cocoons and higher price per kg of
cocoons. This result corroborates with finding of Manimegalai and Aruna (2010b) who
reported that Benefit – Cost ratio from double cross hybrids was higher than the cross
breed.
The double cross hybrid (CSR6 XCSR26) X (CSR2 X CSR27) and its reciprocal
crosses (CSR2 X CSR27) X (CSR6 X CSR26) performed better on V1 mulberry variety
during both first and second rearing with respect to economic parameters, cocoon yield
and benefit – cost ratio under laboratory. Similarly the double cross hybrid performed
better in the farmer field with respect to economic parameter and benefit cost ratio.
Hence, double cross hybrid and its reciprocal cross can be commercially exploited in
central dry zone of Karnataka for higher returns.
Future line of work
1. Double cross hybrid best suitable in CDZ of Karnataka as evidenced by rearing
performance of economic parameters of the cocoon. However, there is a yield
difference between the farmers. However, study can be conducted on mulberry
cultivation as influenced on cocoon yield.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
45
2. The soil health in relation to mulberry leaf production and its influence on
performance of double cross hybrids needs to be explored.
3. Popularization of double cross hybrids among the farmers in different regions
through different extension programmes.
4. The double cross hybrids DH1 and DH2 performed better when it was reared at
Department of Sericulture, GKVK, UAS, Bangaluru. Hence, the same hybrids
performance may be studied farmer level under zone 5 also. So that the
possibility of exploitation of DH1 and DH2 to the benefit of farmers of zone 5
may be.
46
Sharanyakumar Gowda, Y.K.
VI SUMMARY
The results of the investigation on the performance of two double cross hybrids,
viz., (CSR6 X CSR26) X (CSR2 XCSR27) and (CSR2 X CSR27) X (CSR6 XCSR2) in
comparison with standard check CSR2 X CSR4 (bivoltine hybrid) and PM X CSR2
(cross breed) carried out at the Department of Sericulture, University of Agricultural
Sciences, Bangaluru and KVK, Hiriyur, Chitradurga District is summarized below.
The early larval duration was significantly low in double cross hybrids DH1 and
DH2 (85.67 h, 85.67 and 85.63 h, 85.63 h) when compared to CSR2 X CSR4 (85.80 h
and 85.77 h). However, the breed PM X CSR2 registered lowest early larval duration
(83.49 h and 83.47 h) at both first and second rearing.
The total larval duration was significantly low in double cross hybrids DH1 and
DH2 (613.7 h, 611.04 h and 613.7 h, 611.04 h) when compared to CSR2 x CSR4 (613.8
h and 612.03 h). However, the breed PM X CSR2 registered lowest total larval duration
(599.7 h and 586.14 h).
The larval weight was significantly high in double cross hybrids DH1 and DH2
(43.33 g, 42.27 g and 43.17 g, 42.27 g) when compared to CSR2 x CSR4 (37.38 g and
36.76 g) However, the breed PM X CSR2 registered lowest larval weight (33.83 g and
31.31g) at both first and second rearing.
The cocoon weight was significantly high in double cross hybrids DH1 and DH2
(2.07 g, 2.04 g, and 2.04 g, 2.03 g) when compared to CSR2 x CSR4 (1.85 g and 1.82 g)
However, the breed PM X CSR2 registered lowest cocoon weight (1.74 g and 1.72 g ) at
both first and second rearing, respectively.
The shell weight was significantly high in double cross hybrids DH1 and DH2
(0.488 g, 0.476 and 0.480 g, 0.472 g) when compared to CSR2 x CSR4 (0.432 g and
0.422 g,) However, the breed PM X CSR2 registered lowest shell weight (0.330 g and
0.330 g).
The shell ratio was significantly high in double cross hybrids DH1 and DH2
(23.57 g, 23.33 g and 23.52 g, 23.25 g) when compared to CSR2 x CSR4 (23.35 g and
23.18 g). However, the breed PM X CSR2 registered lowest shell ratio (18.98 and 19.18
g).
The silk productivity was significantly higher in double cross hybrids DH1 and
DH2 (5.99, 5.95 cg/day and 6.10, 5.89 cg/day) when compared to CSR2 x CSR4 (5.35
cg/day and 5.36 cg/day). However, the breed PM X CSR2 registered lower silk
productivity (4.43 cg/day and 4.58 cg/day) at both first and second rearing, respectively.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
47
The ERR was significantly higher in double cross hybrids DH1 and DH2 (98.2%,
98.0 % and 97.6%, 97.4%) when compared to CSR2 x CSR4 (97.80 and 97.20) and were
next to PM X CSR2 (98.5% and 98.0%).
The longest filament length, highest filament weight and fine denier was
significantly higher in double cross hybrids DH1 (1249m, 0.37g, 2.66 and 1237.1m,
0.362 g, 2.63) and DH2 ( 1246.8m, 0.372g, 2.68 and 1233.6m, 0.360g, 2,62) when
compared to CSR2 x CSR4 (1217.4m, 0.38g, 2.80 and 1208m, 0.370g, 2.75) However,
the breed PM X CSR2 registered lower filament length, lowest filament weight and
denier (989.20m, 0.32 g, 2.91 and 982.63m, 0.312g, 2.82) during first and second rearing.
The cocoon yield/100 dfl’s was significantly high in double cross hybrids DH1
and DH2 78.53kg, 78.45kg and 75.5kg, 75.5kg/100 dfls when compared to CSR2 x
CSR4 ( 73.48kg, and 70.2kg/100 dfls ). However, the breed PM X CSR2 registered
lowest cocoon yield (68.89kg and 64.9kg/100 dfl’s).
The data obtained from farmers field revealed that the double cross hybrids
performed better with favorable economic characters, viz., single mature larval weight
(3.89g), cocoon weight (1.96), shell weight (0.42g), shell ratio (21.84%), filament length
(1174m), filament weight (0.34g), denier (2.65) and yield/100 dfl’s (75.6kg) than PM X
CSR2 3.30g, 1.73g, 0.32g, 18.68%, 927.97m, 0.29g, 2.80 and 65.5kg.
Average mulberry leaf production and cost of production per kg of leaf in V1
variety.
Cost of production per kg of cocoon was high in DH1 (Rs 164.34) and CSR2 x
CSR4 (Rs.164.48) on V1variety of mulberry. Cost of production per kg was less in PM X
CSR2 (Rs.163.25).
DH1 and CSR2 X CSR4 recorded the highest average cocoon yield of 183.0 and
177 kg, than PM x CSR2 (163.25 kg). The highest cocoon price was high for DH1
(Rs.443.50) compared to CSR2 XCSR4 (Rs.438.50) and lower price in PM x CSR2
(Rs.392.50). Similarly more average returns per kg was realized by rearing DH1 followed
by CSR2 XCSR4. Lower returns were obtained in PM XCSR2 on V1. The Benefit – Cost
ratio was high in double hybrid, DH1 (1:2.70) followed by CSR2 XCSR4 (1:2.59) and
(1:2.40).
The double cross hybrid, (CSR6 XCSR26) X (CSR2 X CSR27) and its reciprocal
cross (CSR2 X CSR27) X (CSR6 X CSR26) can be commercially exploited in central dry
zone of Karnataka as they exhibited better performance with respect to economic
parameters, cocoon yield, benefit – cost ratio, when reared in the rearing house at
department of sericulture and farmer field conditions.
48
Sharanyakumar Gowda, Y.K.
VII REFERENCE
AIYASWAMY, P.K., 1980, Income and employment potential sericulture in Coimbatore
district. Proc. seminar on sericulture, pp. 239-243.
AKIO YAMAGUCHI, 2001, Future direction of bivoltine silkworm breeding in India.
Indian Silk, 39(9):26-28.
ANONYMOUS, 1973, Mysore state draft for 5th five-year plan (1974-75) planning
department. Government of Mysore, Bangalore, pp.441-461.
ANONYMOUS, 1975, Silkworm breeding and genetics section. Annual. Report (197475), Central Sericultural Research and Training Institute, Mysore, pp. 37-38.
ANONYMOUS, 1977, Sericulture, Karnataka (1977-78), Department, Government of
Karnataka, Bangalore, pp. 80-86.
ANONYMOUS, 1982, Behavior and performance of NBJ, NBH and NBZ series. Annual.
Report (1981-82), C.S.R & TI., Mysore, pp. 80-84.
ANONYMOUS, 1983a, Breeding for shorter larval period. Annual. Report (1982-83)
C.S.R & TI., Mysore, pp. 11-14.
ANONYMOUS, 1995, Research extension centres: Silkworm rearing. Annual Report,
CSR &TI, Pampore, pp. 47-58.
ANONYMOUS, 1998, Research extension centres: Silkworm rearing. Annual Report,
CSR &TI, Pampore, pp. 44-51.
ANONYMOUS, 2002, Research extension centres: Silkworm rearing. Annual Report,
CSR & TI, Pampore, pp. 45-57.
ANONYMOUS, 2003a, Double hybrid for high egg recovery and crop stability. Indian
Silk, 34(4):14.
ANONYMOUS, 2003b, Manual on bivoltine silk reeling technology. CSR&TI,
Bangalore, p.122.
ANONYMOUS, 2004a, Activities of sub-units demonstration cum technical services
centre. Dharwad, Karnataka. Annual Report, CSTRI, Bangalore, pp. 53-60.
ANONYMOUS, 2004b, Research extension centre: Silkworm rearing. Annual Report,
CSR & TI, Pampore, pp. 54-75.
ANONYMOUS, 2005, Authorization of silkworm hybrids. Indian Silk, 44(8):9.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
49
ANONYMOUS, 2007, Major research achievement of CSB institute Part I. Indian Silk,
45(7):10-13.
ANONYMOUS, 2010, Sericulture statistics. Annual Report, (2009-2010), CSB,
Bangalore.
ANONYMOUS, 2012, Sericulture statistics. Annual Report, (2011-2012), CSB,
Bangalore.
ANONYMOUS, 2013, Note on the performance of Indian silk industry and functioning.
Central Silk Board, Bangalore, p. 59.
BABULAL, SIDDIQUI, A.A., KHATRI, R.K. AND SHARMA, A.K., 2005, Bivoltine
cocoon production-an analysis of yield gaps and constraints. Indian silk,
44(4):13-15.
BALASARASWATHI, S., LAKSHAMANAN, S., MANI, A. AND QUADRI, S.M.H.,
2005, Comparative economics of mulberry and cocoon production in Erode and
Dharmapuri districts of Tamil Nadu. Indian J. Seric., 45(1):58-6.
BASAVARAJA, H.K., JOLLY, M.S., VIJAYAKUMAR, H.V., VINDHYA, G.S.,
NOAMANI, M.K.R. AND NAGARAJU, J., 1983, Studies on bivoltine double
hybrids. Natl. Semi. Silk Res. Dev., C.S.B., Bangalore, p.14.
BASAVARAJA, H.K., MAL REDDY, N., NIRMAL KUMAR, S., HAREESH
KUMAR, H.R. AND DATTA, R.K., 1995, Identification of productive F1
hybrids, foundation and double hybrids with high raw silk recovery. Annual
report, CSR & TI, Mysore, pp. 41-42.
BASAVARAJA, H.K., MAL REDDY, N., NIRMAL KUMAR, S., HAREESH
KUMAR, H.R. AND DATTA, R.K., 1996, Silkworm crop improvement. Annual
report, CSR & TI, Mysore, p. 44.
BASAVARAJA, H.K., MAL REDDY, N., NIRMAL KUMAR, S., HAREESH
KUMAR, H.R. AND DATTA, R.K., 1998, New approaches to bivoltine
silkworm breeding. In: Silkworm Breeding (Ed. G. Sreerama Reddy) Oxford and
IBH publishing Co. Pvt. Ltd., New Delhi, pp. 293-304.
BENCHAMIN, K.V. AND KRISHNASWAMI, S., 1981, Studies on the egg production
efficiency in silkworm, Bombyx mori L. (ii). Egg production efficiency in hybrid
parents and its effective application. Proc. Seric. Symp. Semi. (1980), TNAU,
Coimbatore, pp. 7-14.
CHANDRA REDDY, T. AND ESWAR PRASAD, Y., 1992, An econometric analysis of
technical efficiency on farm resources in Sericulture industry. Indian Journal of
Agricultural Economics, 27(3):12-18.
50
Sharanyakumar Gowda, Y.K.
CHANDRASHEKAR REDDY, 1985, Income and employment generation in sericulture
Vis a Vis alternative crops in Hosur taluk of Dharmapuri district, M.Sc. Thesis,
(Unpublished) Univ. Agril. Sci., Bangalore.
CHANRASHEKAR REDDY, RAMAN, R.R., KESAV REDDY, T.R., NAGARAJ, N.
AND ACHOTH, L., 1988, An economics evaluation of Sericulture some
empirical evidences. International Congress in Tropical Sericulture Practices,
Bangalore, pp. 15-27.
CHANDRASHEKAR, K.R., 2003, Evaluation of bivoltine pure races and bivoltine
hybrid of Bombyx mori L. in west zone of Tamil Nadu. M.Sc. Thesis, Tamil
Nadu Agricultural University, Coimbatore, p. 129.
CHANDRASHEKARAN, G. AND RADHA, N.V., 1991, The economics of Sericulture.
Kisan World, 23(3):26-28.
DANDIN, S.B. AND KUMARESAN, P., 2003, An empirical analysis of cost of cocoon
production Indian Silk, 42(4):5-10.
DANDIN, S.B. AND BASAVARAJ, H.K., 2005, Large scale bivoltine farming – reality
under tropical conditions. Indian Silk, 43(4):10-12.
DANDIN, S.B., BASAVARAJ, H.K. AND SURESH KUMAR, N., 2005, Silkworm
breeds and hybrids at Bangalore. Annual report, CSR & TI, Mysore, p. 51.
DANDIN, S.B., SURESH KUMAR, N., BASAVARAJ, H.K., MAL REDDY, N.,
KALPANA,
G.V.,
JOGE,
P.G.,
NATARAJU,
B.,
BALAVENKATASUBBAIAH AND NANJE GOWDA, B., 2006, Development
of new bivoltine silkworm hybrid, Chamaraja (CSR50 X CSR51) of Bombyx
mori L. for tropics. Indian J. Seric., 45(1):35-44.
DANDIN, S. B. AND GIRIDAR, K., 2010, Handbook of Sericulture Technologies,
Central Silk Board, p:1-423.
DANIEL, MASE, K. AND NAGASAKA, 2000, Bivoltine Sericulture. Bull. Inst. Seri.
Entomol. Sci.,19:49-57.
DAS, B.K., SARKAR, J., DAS, C., DAS, N.K. and SEN, S.K., 1995, Seasonal effects on
the relative performance of five bivoltine breeds of silkworm, Bombyx mori L.,
in Malda. Uttar. P.X. Zool., 15(2):91-96.
DAS MOHAPATRA, D.P., RAO, K.V.S.N., SINHA, A.K., SINHADEO, S.N. AND
BARDAIYAR, V.N., 1997, Evaluation of silkworm hybrids under race
authorization programme. Annual Report, CSR&TI, Barhampore, p. 55.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
51
DATTA, R.K., 1984, Improvement of silk worm races (Bombyx mori L.) in India.
Sericologia, 24(1):393-415.
DATTA, R.K., SURESH KUMAR, N. AND MAL REDDY., 2001, “CSR18 x CSR19”
A robust bivoltine hybrid for all season rearing. Indian Silk, 22(7):5-8.
DATTA, R.K., 2003, Silkworm breeding in India and its future needs. National
Conference on Tropical Sericulture for Global competitiveness, CSR & TI,
Mysore, 5-7th Nov., pp. 5-18.
DATTA, T., SAHA, A.K., DAS, S.K., KAR, N.B. AND SARKAR, A., 2006, Induction
of trimoulting in bivoltines and its bivoltine and its utility for mulit x bi seed
production in west India. Indian Silk, 45(8):5-7.
DAYANANDA, SATISH KULKARNI, MOHANA RAO, P.R., OBALAIAH
GOPINATH, SUNDARA MURTHY AND NIRMAL KUMAR, 2011,
Evaluation and Identification of Promising Bivoltine Double Hybrids of the
Silkworm, Bombyx mori L. for Tropics through Large Scale in-House Testing,
Int. J. Indust. Entomol, 23(2) pp. 187-191.
DEVRAJ URS, D., 1976, Sericulture can create more jobs with minimum capital
investment. Indian Silk, 15(4):13–15.
DODMANI, M.J., 1996, Economics of silk production in Gulbarga district, M.Sc. (Agri.)
Thesis, Univ. Agril. Sciences, Dharwad, p.139.
FOTADAR, B. K., BINDROO, B.B. AND TRAG, A.R., 1999, Field evaluation of new
bivoltine hybrids in sub-tropical Jammu. Indian J. Seric., 38(2):45-48.
GANGWAR, S. K., 2011, Screening of popular bivoltine silkworm hybrid breeds of
West Bengal in Monsoon and autumn seasons of Uttar Pradesh climatic
condition. Asian J. Exp. Biol. Sci., 2(4):704-714.
GIRIDHAR, K., BENCHAMIN, K.V. AND NAGARAJ, C.S., 1986, Socio– economic
evaluation of sericulture in Karnataka. Indian Silk, 25(18):21-24.
GOMEZ, K. A. AND GOMEZ, A. A., 1984, Statistical procedures for Agric. Res. 2nd
Ed. John Wiley and Sons, New York.
GOVINDAN, R., MAGADUM. S.B. AND ASHOKA, J., 1990, Variability in larval, silk
glands, cocoon and shell weight and utilization indices of selected silkworm
races of Bombyx mori L. Mysore J. Agri. Sci., 24:222-224.
HAJARE, T.N., JADHAV, A.D., JAGADISH PRASAD, CHALLA, O. AND
KALANTRI, L.B., 2008, Sericulture brings better income. Indian Silk, 46(9):27.
52
Sharanyakumar Gowda, Y.K.
HARADA, C., 1961, Heterosis of the quantitative characters in the silkworm. Bull.
Sericult. Exp. Sta., Japan, 17(1):1-52.
HIRIYANNA, SWAMY, T.P., KUMARESAN, P. AND VIJAYAPRAKASH, N. B.,
2002, Comparative economics of bivoltine hybrids with multi X bi hybrid
cocoon production. Indian J. Seric., 41(1): 38-41.
IYENGAR, M.N.S., JOLLY, M.S., DATTA, R.K. AND SUBRAMANIAN, R.K., 1983,
Relative silk productivity of different silkworm breeds and its use breeding
index. Natl. Semi. Silk Res. & Dev., C.S.B., Bangalore, pp.10-13.
JAGANNATHAN, N., 1995, Impact of sericulture on Income and employment
generation. Indian Silk, 35 (9):11-16.
JOGE, P.G., PALLAVI, S.N., NASEEMA BEGUM, S., MAHALINGAPPA, K.C.,
MALIKARJUNA AND DANDIN, S.B., 2003, Evaluation of double hybrid of
silkworm, Bombyx mori L. in the field. National Conference on Tropical
Sericulture for global competitiveness, CSR & TI, Mysore, p. 26.
JOLLY, M.S., 1982, Economics of sericulture under irrigated conditions, Central
Sericultural Research and Training Institute, Mysore, Project No. 2:19.
JOLLY, M.S., 1983, Silkworm Genetics and Breeding. Natl. Semi. Silk Rev. Dev., CSB.,
Bangalore, p.19.
JOLLY, M.S., 1986, Organisation of Industrial Bivoltine Grainage for Tropics.
CSR&TI., Mysore, p. 39.
KALAPPA, H.K., 2001, Performance of promising of BL24 X NB4D2 under post
authorization discipline programme. Indian J. Seric., 40:134-138.
KAMAJYO, IKIO, NAKAJIMA, Y., NAKAGAWA, H. AND FUKAZAWA, M., 1985,
Breeding of the races N135 and C136. Bull. Sericult. Expt. Stan., 29:499-531.
KARIAPPA, B.K. AND RAJANNA, R.K., 2004, Development of multivoltine silkworm
breeds/hybrids in India for commercial exploitation, Indian. J. Seri., 43(1) 18-24.
KARENNAVAR, M.F., 1973, Structure of sericulture industry in Karnataka. Southern
Economist, 12 (2): 27-31.
KASIVISVANATHAN, K. AND KRISHNAMURTHY, S., 1972, Package of practices
for mulberry cultivation. Seminar report, CSB, Bombay.
KARUTAGI, M.G., 1991, Production and marketing of silk cocoons in Bijapur District,
Karnataka- An economic analysis. M.Sc. (Agri.) Thesis, Univ. Agril. Sciences,
Dharwad, p.124.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
53
KISHORE,
S.
N.,
SIVARAMI REDDY
S.,
VIDYUNMALA.
AND
SURYANARYANA, N., 2002, Evaluation of new mulberry silkworm hybrids
under semi-arid conditions of Andhra Pradesh. In: Advances in Indian
Sericulture. Eds. Dandin, S.B. and Gupta, V.P., CSR&TI, Mysore, pp. 319-322.
KRISHNAMURTHY, S., 1972, Sericultural research and its achievements in India.
Journal of Industry and Trade, Ministry of Commerce and Trade, New Delhi.
KRISHNASWAMI, S., NARASIMHANNA, M.N., SURYANARAYANA, S.K. AND
KUMARARAJ, S., 1973, Sericulture Manual. Silkworm rearing. FAO
Agricultural Services Bulletin, Rome. p. 41.
KRISHNA KUMAR, D.V., 2001, Evaluation of new bivoltine hybrids of silkworm
Bombyx mori L. based on evaluation index. M.Sc. (Agri.) Thesis, University of
Agricultural Science, Bangalore, p. 209.
KRISHNA RAO, S., RAJENDRA MUNDHUR, RAJANNA, G.S., RAGHURAMAN,
R., SHIVAMALLU, M.L. AND MAHADEVAPPA. L., 1997, New bivoltines
for tropical conditions. Indian Silk, 36(6):5-10.
KUMARESAN, P., BOGESHA, K., TSUCHIYA H., VIJAYA PRAKASH, N.B. AND
KAWAKAMI, K., 2002, An economic analysis of CSR hybrid cocoon
production under PPPBST project in Karnataka. Advances in Indian Sericulture
Research, (Ed. Dandin S. B. and V.P., Gupta), CSR & TI, Mysore, pp. 500-504.
KUMARESAN, P. AND VIJAY PRAKASH, N.B., 2001, Economics of sericulture vis –
a – vis competing crops in Erode district of Tamil Nadu. Indian J. of Seric., 40
(2):142-146.
LAKSHAMANAN, S., SEN, A.K. AND THIAGARAJAN, V., 1989, Economic trends of
area, production and productivity of mulberry raw silk in India. Agri. Sit. India,
44(2):115-166.
LAKSHAMANAN, S., GANAPATHY RAO, R., MALLIKARJUNA, B.G., GEETHA
DEVI, R.G., JAYARAM, H., SUBRAMANAN, M,R. AND DATTA, R.K.,
1996, Economic issues of production of mulberry cocoon in Tamil Nadu – A
micro economic studies. Indian J. Seric., 35(2):128-131.
LAKSHAMANAN, S., GANAPATHY RAO, R., MALLIKARJUNA, B.G. AND
GEETHA DEVI, R.G., 1997, Economics of Sericulture – an update. Indian Silk,
36(1):21-23.
LAKSHMANAN, S., SEN, A.K. AND THIAGARAJAN., 1998, Economic trends of
area, production and productivity of mulberry raw silk in India. Agri. Sit. India,
44(2):115-116.
54
Sharanyakumar Gowda, Y.K.
LAKSHAMANAN, S., GEETHA DEVI, R.G. AND SUMA, N., 2000, Economics of
bivoltine versus cross breed cocoon production in K.R Nagar taluk of Mysore
District. Indian J. of Seric., 39 (2):149-151.
LAKSHMANAN, V., SEN, A.K. AND RAJALASHMI, E., 2004, Improvement of
Productivity through bivoltine breeding hill areas. Annual Report, CSR & TI,
Mysore, pp. 70-71.
LAKSHMANAN, V. AND SURESH KUMAR, N., 2012, Analysis of heterosis in new
double hybrid combinations in bivoltine silkworm Bombyx mori. L.
International. J. Sci. Nature, 3(1):197-204.
MAHADEVAPPA, D., 1998, Maintenance and multiplication of silkworm breds.
Silkworm Breeding, (Ed. G. Sreerama Reddy), Oxford and IBH Publishing Co.
Pvt. Ltd., New Delhi, pp. 218-226.
MAL REDDY, N., SURESH KUMAR, N., JOGE, P.G., BASAVARAJ, H.K. AND
AHSAN, M.M., 1995, Identification of productive F1 hybrids, foundation
crosses and double hybrids with high raw silk recovery. Annual Report,
CSR&TI, Mysore, pp. 46-47.
MAL REDDY, N., SURESH KUMAR, N., JOGE, P.G., BASAVARAJ, H.K.,
KALPANA, G.V., JAYASWAL, K.P. AND RAMASWAMY, G.N., 1998,
Identification of productive F1 hybrids, foundation cross and double hybrids
with high raw silk recovery. Annual Report, CSR & TI, Mysore, pp. 53-54.
MAL REDDY, N., BASAVARAJ, H.K., SURESH KUMA, N., NIRMAL KUMAR, S.,
and KALPANA, G.V., 2003, Breeding of bivoltine double hybrid
(CSR6xCSR26) X (CSR2xCSR27) of silkworm, Bombyx mori L. for commercial
exploitation. National Conference on Tropical Sericulture for Global
Competitiveness, CSR& TI, Mysore, p.18.
MAL REDDY, N., NIRMAL KUMAR, S., NASEEMA BEGUM, S. R. MOORTHY,
S.M. AND QADRI, S.M.H., 2012, Performance of bivoltine silkworm hybrids of
Bombyx mori L. involving parental foundation crosses of different generation.
International Journal of Research in Zoology, 2(1):1-5.
MANIMEGALAI, S. AND ARUNA, G.R., 2010a, Performance of double hybrids of
Bombyx mori L. in Tamil Nadu, Indian silk, 48(9):12-14.
MANIMEGALAI, S. AND ARUNA, G.R., 2010b, Performance of double hybrids of
silkworm, Bombyx mori L. in western zone of Tamil Nadu. Bull. Ind. Acad. Seri.,
14(2):13-28.
MARIBASHETTY, V.G., RAJU, P.J., RAJANNA, G.S., KALPANA, G.V.,
SUBRAMANYA. AND SEEMA REDDY G., 1998, Evolution of hardy
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
55
bivoltine races of silkworm, Bombyx mori L. for tropics. In: Silkworm Breeding,
(Ed. G. Sreerama Reddy) Oxford and IBH Publishing Co. Pvt. Ltd., New Delhi,
India, pp.10-118.
MOHAN, B., VENKETANARASAIAH, P. AND KUBERUDU, B., 1990, Sericulture
for rural development. Kadhi Gramodyog, 36(4)167-172.
MUNIKRISHNAPPA, H.M., HIRIYANNA, T.S., MAHADEVAMURTHY. AND
GEETHADEVI, R.G., 2007, Kolar Gold hybrids: Factors for preference. Indian
Silk, 46(2):5.
MURTHY, S.R.S., 1977, Economics of silk cocoons production with irrigated mulberry
in Devanhally taluk, Bangalore district, M.Sc (Agri.) Thesis, (Unpublished) Univ.
Agril. Sci., Bangalore.
NANAIAH, 1981, Sarkari nowkariyannu thyajisida, Reshme krushi, 4:25-28.
NANJA REDDY, C., HIREMATH, K.C. AND HADSON, E.H., 1971, Farm Planning,
University. Agri. Sci., Bangalore.
NANJE GOWDA, B. AND MAL REDDY, N., 2005, Effect of different environmental
conditions on popular multivoltine x bivoltine hybrids of silkworm, Bombyx
mori L. and their effect on reeling performance. Indian J. Seric., 45(2)134-141.
NARASIMHANNA, M.N. AND KASIVISWANATHAN, K., 1972, Hippunerale
Besaya. Central Sericulture Research and Training Institute, Mysore.
NARASIMHANNA, M.N., 1973, Achievements of the Central Sericulture Research and
Training Institute, Mysore, Central Silk Board. Bambay.
NARASIMHANNA, M.N., CHANDRASEKARAIAH, GEETHADEVI, R.G.,
MUNERA, N. AND PRADHA, G., 1976, Ecogenetic attributes of newly
evolved bivoltine hybrid ‘Nandi’ in Bombyx mori (L.) Proc. Dunn. Dozh. Symp.
Genet., Univ. of Mysore, pp. 397-386.
NARASIMHANNA, M.N., 1985, Silkworm seed organization and technology for India
during the seventh plan. Indian Silk, 24(4):22-26.
NARAYANA SWAMY, K.C., 1988, Performance of single and double cross hybrid of
some bivoltine races of silkworm, Bombyx mori L. M.Sc. Thesis, University of
Agricultural Sciences, Bangalore, p. 206.
NASEEMA, BEGUM, A., BASAVARAJ, H.K., JOGE, P.G., PALLAVI, S.N.,
MAHALINAGAPPA, K.C. AND DANDIN, S.B., 2005, Evaluation of Chinese
bivoltine double hybrids of silkworm, Bombyx mori L. Indian J. Seric., 44(1):6974.
56
Sharanyakumar Gowda, Y.K.
NATARAJ, N. AND MATHEW THOMAS, 1976, Economics of bivoltine sericulture in
Karnataka, Indian Silk, 15:7–12.
NANAVATY, M.M., 1965, Silk From Grub to Glamour. Paramount Publishing House,
Bombay, p. 277.
NEELAKANTA SHASTRY, T.V., 1982, Cost structure of a sericulture industry in
Chitoor district of Andhra Pradesh, M.Sc. (Agri.) Thesis, Agriculture College,
Bapathla, A.P.
NIRMAL KUMAR, S., RAMESH BABU, M., MAL REDDY, N., BASAVARAJ, H.K.,
AND AHSAN, M.M., 1996, Field performance of CSR bivoltine hybrids Annual
report, CSR&TI, Mysore, p.44.
NIRMAL KUMAR, S. AND SREERAMA REDDY, G., 1998, Evaluation and selection
of potential parents for silkworm breeding. In: Silkworm Breeding, (Ed. G.
Sreerama Reddy) Oxford and IBH Publishing Co. Pvt. Ltd., New Delhi, India,
pp. 63-78.
NIRMAL KUMAR, S., RAMESH BABU, M., MAL REDDY, N., BASAVARAJ, H.K.
AND DATTA, R.K., 1998, Double hybrids for improvement of silk production
in silkworm, Bombyx mori L. In: Silkworm Breeding, (Ed. G. Sreerama Reddy)
Oxford and IBH Publishing Co. Pvt. Ltd., New Delhi, Calcutta, India, pp. 209217.
NIRMAL KUMAR, S., MAL REDDY, N., BASAVARAJ, H.K., RAMESH BABU, M.,
SURESH, N., AHSAN, M.M. AND DATTA, R.K., 1999, Identification of
bivoltine double hybrids for commercial exploitation. Indian J. Seric., 38(2):135139.
PANNENGPET, P., 1973, Survey on the practical characters of three-way cross and
double cross hybrids of bivoltine silkworm races. Bull. Thai Seric. Res.
Train.Centre, Thailand, 3:81-82.
PANNENGPET, P. AND JAROONCHAI, J., 1975, Survey on the practical characters of
double cross hybrids of bivoltine silkworm races (2). Bull. Thai Seric. Res.
Train.Centre, Thailand, 5:85-86.
PATEL, A.R., 1976, Sericulture – A labour intensive industry. Southern Economist, 15
(3): 15-18.
PETKOV, N., IGNATOVA, L., NACHEVA. Y. AND TZENOV, P., 2000, Study of the
average values and variability of the basic productive indexes of double, triple
and terta-cross hybrids of silkworm Bombyx mori L. Bulg. J. Agric. Sci., 6:593598.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
57
QUADIR, S.M. AND MIR NISAR, 2004, Evaluation of hybrids for identification of high
ranking season-specific hybrids for commercial exploitation under temperate
climatic conditions Annual report, CSTR & TI, Pampore, p. 20.
QUADIR, S.M., MIR NISAR AND KHAN, M.A., 2005, Improvement of silkworm,
Bombyx mori L. Annual Report, CSR & TI, Pampore, p. 20.
QUADIR, S.M. AND DANDIN, S.B., 2006, Bivoltine Sericulture promotion the Tamil
Nadu way. Indian Silk, 45(2):11-15.
QUADRI, S. M. H., NASEEMA BEGUM, A., MAL REDDY, N. AND NIRMAL
KUMAR, S., 2013, Studies on evalution and selection of three-way cross
bivoltine silkworm hybrids of Bombyx mori L. for commercial exploitation.
International Journal of Biological Science, pp. 2249-9687.
RAJAN, R.K., HEMANTHRAJ, M.T., SINGH, G.P. AND DATTA, R.K., 2000,
Popularization of bivoltine sericulture technology. Indian Silk, 39(6)22-24.
RAJANNA, G.S., SHIVANANDARADHYA, H.S., DINESH, M., PRABHAKAR RAO,
A., KRISHNA RAO, S., MUNDAKUR, R. AND RAGHURAMAN, R., 2001,
Field popularization of “MH1”, and its hybrid MH1 x NB4D2. Abstract.
National seminar on mulberry sericulture research in India, KSSR&DI
Bangalore, 26-28 Nov., p. 172.
RAMA KRISHNA, K. B., 1987, Cost – benefit analysis of silk cocoons production.
M.Sc. (Agril.) Thesis, Univ. Agril. Sciences, Bangalore, p. 126.
RAMAMOHAN RAO, P., IYENDRA, M.N.S., NOAMANI, M.K.R., BENCHAMIN,
K.V., RAJURS, R., NAGARAJ, C.S. AND BASAVARAJA, H.K., 1987, Recent
approaches in bivoltine breeding. Indian Silk, 26 (5):26-28.
ROOPA V. TEMKAR, 2002, Effect of different varieties of mulberry and foliar
supplementation on the economic characters of hybrids of silkworm, Bombyx
mori L. M.Sc. Thesis, Tamil Nadu Agricultural University, Coimbator, p. 123.
SAHABALMIK, B. AND MUKHOPADHYAY, A., 1977, Cost profitability and
employment potential in the production of mulberry silk fibre in West Bengal.
Agril. Situation in India, 35:15 – 19.
SARASWATH, S.B., SINGH, B.D. AND RAMAHANTH, 2003, Evolution of some
bivoltine hybrid for Purvanchal region of Uttar Pradesh. National conference on
tropical sericulture for global comparatives, 5-7 November, CSR & TI, Mysore,
p. 77.
SENGUPTA, K., 1969, An analysis of genotype environment interaction in some races of
silkworm, Bombyx mori L. Indian J. Seric., 8(1):4-6.
58
Sharanyakumar Gowda, Y.K.
SIDDAPAJI, C., VASUDHEVA, M., SHASHIDHAR, H.R. AND SHIVASHANKAR,
T., 1983, Investigations on Sericultural practices in Karnataka. National Semi.
Silk Res. Central Silk Board, Bangalore, p. 39.
SIDHU, N.S., SINGH, K., VENUGOPAL PILLAI, S. AND SREENIVASAN, R., 1969,
Performance of some of the breeds of silkworm, Bombyx mori L. Silkworm
Information bulletin, 1:41-53.
SOHN, K.W. AND RAMIREZ, L., 1999, Comparative of the variation in cocoon quality
among the single, three – way and double cross hybrid in the silkworm, Bombyx
mori L. Sericologia, 39(1):15-26.
SOMESHEKAR, T.H., 1994, Post cocoon processing scenario in India. International
Conference on Sericulture, Global Silk Scenario, CSR & TI and ICTRETS,
Mysore, pp. 83-87.
STRUNNIKOV, V.A., 1983, Control of Silkworm Reproduction, Development and Sex.
Mir Publishers, Moscow, p. 280.
SUBBA RAO, G., 1994, Evaluation and authorization of parent race and their hybridsmodalities. Proceeding of National Workshop on silkworm Breeding, University
of Mysore, Mysore, Oxford and IBH Publishing Co. Pvt. Ltd., New Delhi, India,
P. 60.
SURESH KUMAR, N. AND TOSHI YAMAMOTO, 1996, Maternal effect of resistance
to high temperature in F1 hybrids between polyvoltine and bivoltine silkworm
race. Annual Sericulture Confernece, Nigata, Japan, 9-10th November 1995. pp.
22-24.
SURESH KUMAR, N., HARJEET SINGH, N., KALPANA, G.V., BASAVARAJ, H.K.,
NANJE GOWDA, B., MAL REDDY, N., JOGE, P.G. AND DANDIN, S.B.,
2005, Evaluation of temperature tolerant and temperature sensitive breeds of
bivoltine silkworm, Bombyx mori L. Indian J. Seric., 44(2):186-194.
SURESH KUMAR, N., HARJEET SINGH, SAHA, A. K. AND BINDROO, B. B., 2011,
Development of bivoltine double hybrid of the silkworm, Bombyx mori L.
tolerant to high temperature and high humidity conditions of the tropics.
Universal J Eniv. Res. and Tech., 1(4):423-434.
TANAKA, S., KINOSHITA, D. AND TANIGUCHI, Y., 1980, Studies on the breeding
of the economical silkworm race, N142-N143 x C142-C143. Bull. Sericult. Expt.
Stan., 28: 237-251.
TELI, V.S., PAWAR, M.B., PATIL, R.R. AND KALBHOR, S.E., 1984, Performance of
some mulberry silkworm strains and hybrids. J. Maharashtra Agric.Univ., 9:112114.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
59
TRIVEDY, K. AND NAIR, K.S., 1999, Feed conversion efficiency of improved multi x
bivoltine hybrid of silkworm Bombyx mori L. Indian J. Seric., 38:30-34.
UDUPA, S.M. AND VISWESWARA GOWDA B.L., 1988, Heterotic expression in silk
productivity of different crosses of silkworm, Bombyx mori L. Sericologia,
28(3):395-399.
ULLAL, S. R. AND NARASIMHANNA, M.N., 1978, Hand book of practical
sericulture. Central Silk Board, Bombay, pp. 172 – 175.
VEERANNA GOWDA, ASHWATH, S. K. AND KALPANA, G. V., 2012, Evaluation
of four-way crosses for selection of suitable hybrids of silkworm, Bombyx mori
L. Indian J. Seric., 51 (2):143-149.
VEERANNA GOWDA, ASHWATH, S. K. AND KALPANA, G. V., 2013, Evaluation
and Identification of Potential Bivoltine Silkworm Hybrids of Bombyx mori L. J.
of Entom. and Zoology Studies, 1 (6): 39-43.
VENAKATA RAO, B., 1974, Report on financing the crash programme for the
development of sericulture in Karnataka. Agriculture Credit Development,
Reserve Bank of India, Bombay.
VENKATESHWARA RAO, P., KUMARESAN, P. AND VIJAY PRAKASH, N.B.,
2001, Comparitive economics of cocoon production in coastal area and
traditional area of Andhra Pradesh. Indian J. of Seric., 40(2) : 147 – 150.
VENUGOPALA PILLAI, S., MALA, V., RAJAN. AND SINDAGI, S.S., 1987, Cocoon
crop results of bivoltine hybrids reared with local mulberry variety and raised
condition. Indian Silk, 26(7):12-14.
VIJYALAKSHMI, G., SUBRAMA RAJU, K. AND KRISHNAIAH, J., 1991,
Employment generation through Sericulture in Andhra Pradesh. Indian Silk, 25 –
27.
YADAIAH AND SARANGPANI, 1994, Economics of Sericulture – A micro level
study. Agril. Banker, 17 (1):38 – 40.
YOKOYAMA, T., 1959, Silkworm Genetics Illustrated. Japan Society for Promotion of
Science, Japan, p. 185.
YOAKOYAMA, T., 1973, History of Entomolgy. Annual Review-Palo. Alto., California,
pp. 267-2384.
YOKOYAMA, T., 1979, Silkworm selection and hybridization. Working papers, The
Rockefeller Foundation, Genetic in relation to Insect Management, pp. 71-83.
60
Sharanyakumar Gowda, Y.K.
ZITA, L., SANCHEN, PATRIA, G., BALANAY, SERENITA S., OMPAY AND
BASAEN, M., 2003, Comparative study on cocoon characters of F1 single cross
hybrid and F1 double cross hybrid of silkworm (Bombyx mori L). Technical and
semi-technical publication Textile Research Institute – Department of Science
and Technology, 3:1656 – 4744.
ZULAWSKA, 1981, Nation Report of Poland. Sericologia, 21:98-105.
The performance of double cross hybrids of Silkworm in Central dry zone, Karnataka
61