IndianJ. Nemato/. 28 (2): 159-162 (1998)
EFFECT OF DIFFERENT pH LEVELS ON THE DEVELOPMENT
AND MORPHOMETRICS OF HETERODEARA ZEAE
ON MAIZE
MAHIPALSINGH,ARUNAPARIHARANDAU.
SIDDIQUI
Department of Nematology, Rajasthan Agricultural University Campus, Udaipur -313 001
Abstract: The effect of different pH levels on the development and morphometries
of corn cyst nematode, Heterodera zeae was studied. The results revealed that the plant
growth characters were observed maximum at pH 9.0 whereas maximum nematode
population was observed at neutral pH level 7.0. The morphometric characters of
the nematode were significantly decreased at pH 9.0 and 5.0 as compared to neutral pH
7.0.
Key words: Heterodeara zeae, maize and pH levels.
Maize is one of the most important
cereal crops grown in all types of soils.
The performance of this crop is greatly
influenced by several abiotic. factors, of
which soil pH is one such important factor
which not only influences the plant growth
but also the development of Heterodera
zeae, a pest of maize.
MATERIALS
AND METHODS
To study the effect of different levels
of soil pH on nematode development and
morphometrics, an experiment was carried
out in 15cm size earthen pots. These pots
were filled with sterilized soil. Three pH
levels viz. 5.0, 7.0 and 9.0 were adjusted
using a pH meter by adding required
amount of normal Hel and 0.1% NaOH.
The soil pH was kept stabilized by adding
buffer solution to the soil. Two seeds of
maize var. Ganga-5 were sown in each pot
and each treatment was replicated thrice.
After gennination of seeds only one healthy
plant in each pot was maintained. At four
leaf stage 500 freshly hatched Jz of H. zeae
were inoculated in each pot. After 60 days
of inoculation the plants were uprooted.
The plants were examined
for the
observations of shoot length and weight,
root length and weight. Number of cysts
per plant, number of eggs and larvae per
cyst and population in the soil was also
estimated.
The measurements of cysts i.e. length
and width were taken by using camera
lucida. The cone-top structure was cut and
cleared with a hair brush and kept in 30%
HzOz solution for 20 min then transfered to
95% alcohol and mounted in glycerine
jelly. The fenestrallength, width and vulval
slit length were measured. The larval
measurements were also taken by using
camera lucida and body dimensions were
tabulated by using de Man's formulae.
RESULTS AND DISCUSSION
Plant growth characters: The results
presented in table I revealed that the
160
MAHIPAL SINGH, ARUNAPARlHAR
AND A.D. SIDDIQUI
statistically at with neutral pH 7.0. The
maximum root length was recorded at pH
9.0 (19.7 cm) followed by pH 7.0 and pH
5.0 (13.5 cm.) The root length obtained
from pH 9.0 was significantly less over
neutral pH 7.0. However, pH 5.0 was
statistically at par with neutral pH 7.0. The
maximum root weight (27.36g) was
maximum shoot length (28.4 cm) was
obtained at pH level 9.0 whichwas followed
bypH 7.0 (25.5 cm) and pH 5.0 (20.3). The
maximum shoot weight was obtained at
pH 9.0 (20.24g) followed by pH 7.0 (18.43
g) and pH 5.0 (14.57 g). The shoot weight
obtained from pH 5.0 was significantly
less over neutral pH 7.0 and pH 9.0 was
Table 1 : Effect of different pH levels on plant growth characters of maize inoculated withH. zeae
28.4
25.5
20.3
27.4
22.7
2.3
13.5
2.5
218.4
3.9
19.7
12.6
2.7
0.2
15.4
18,4
Length
(gm)
Length
(cm)
Weight
Shoot
Root
s. No.
1.
2.
3.
5.0
60.0
6of
.0
7.0
9.0
7.7
5.7
9.3
135.7
120.3
128.7
1No.
18.1
40.3
69.7
2.0
1.2
4.0
8.3
NS
Number
100
of
cc
soil
levels
Number
larvae
larvae
per
of
eggs
per
eggs
cyst
and
andpH
Table 2 : pH
Effect
of
different
soil
levels
on multiplication of H. zeae on maize.
No.
ofcyst
cysts
per
Soil
population
Plant population
EFFECT OF pH LEVELS ON H. ZE4E
161
obtained at pH 9.0 followed by pH 7.0 at pH 9.0 the number of eggs and la.tvae
(22.73 g) and pH 5.0 (18.44 g). These were decreased as compared to neutral pH
results are in accordance with the findings 7.0. The maximum number of cysts in 100
cc soil obtained from pH 7.0 (8.33)
of Jonathan & Vadivelu (1990).
followed by pH 9.0 (6.0) and pH 5.0 (4.0).
Nematode Population : The result on The population of cysts at pH 9.0 and 5.0
nematode population revealed that the was significantly decreased in comparison
maximum number of cysts were obtained to pH 7.0 which supports the finding of
at neutral pH 7.0 (9.33) followedby pH 9.0 Sheila et a1. 1985 and Naseem & Jairajpuri,
(7.66) and pH 5.0 (5.66). The number of 1982.
cysts obtained from pH 5.0 were
significantly lower then neutral pH 7.0 Morphometric measurements
whereas pH 9.0 was at par with neutral pH
(i) Cysts-Maximum
cyst length
7.0. The number of eggs and larvae per
obtained at neutral pH 7.0 (495.0Ilm)
cyst decreased in both pH levels viz. 9.0
followed by pH 9.0 (485.0Ilm) and pH 5.0
and 5.0 as compared to neutral pH 7.0
(362.0~lm).The cyst length at pH 5.0 was
(169.66), while minimum number of eggs
significantly decreased over pH 7.0.
and larvae per cyst were recorded from pH
However, cyst length at 9.0 was at par with
level 5.0 (140.33) followed by pH level 9.0
pH 7.0. The maximum cyst width was·
(160.0). The number of eggs and larvae
obtained at pH 7.0 (384.4llm) followed by
per cyst at pH 5.0 were decreased
pH 9.0 (376.4llm) and pH 5.0 (370.2jlffi).
significantly over neutral pH 7.0 whereas
47.4
1.30
Fenestral
Fenestral
Width
376.4
0.05
0.94
24.8
1.28
1.87
46.2
43.6
22.2
1.24
1.96
50.2
49.6
27.2
485.0
1.07
46.5
N
Sslit
Vulval
Fenestral
462.0
370.2
495.0
384.4
1.82
8.07 pH level
Length
Coneontop
structures
(11)
width
length/width
(11)
(11)
length
Table 3/Width
: Length
Effect
of
different
morphometries
of H. zeae
Cyst
162
MAHIPAL SINGH, ARUNAPARIHAR
AND A.U. SIDDIQUI
and vulval slit length were recorded
maximum at pH 7.0. These characters and
measurements
were
decreased
significantly at pH 5.0 and 9.0 in
comparison to neutral pH 7.0. These
findings are in agreement with the results
of Saheb & Saxena (1988) and Sheila et
(ii) Cone top structure-At pH 9.0 and aI., 1985who observed significant decrease
5.0 the fenestral length and width showed in the morphometric characters of M.
significant decrease compared to neutral incognita when the soil pH was changed
pH 7.0. The fenestral length/width ratio from 7.0 to 5.0.
obtained from pH 7.0, 5.0 and 9.0 were
1.82, 1.96 and 1.87 respectively and were
REFFERENCES
non-significant (Table 3).
Cyst width at both pH 9.0 and 5.0 decreased
significantly over pH 7.0. The cyst length/
width was obtained maximum at pH 9.0
(1.30) followed by pH 7.0 (1.28) and pH
5.0 (1.24). At pH 5.0 this ratio significantly
decreased over pH 7.0 (Table 3).
(iii) Larval Measurement-The larval Jonathan,E.I. & Vadivelu,S. (1990). Effects of
soil pH on the incidence of Meloidogyne
length from pH 5.0 decreased significantly
incognita in bhindi. International Nematol.
over pH 7.0 and was statistically at par
Network newsl. 7 : 13-14.
with pH 9.0. The body width was almost
equal in the larvae measured. The stylet Koshy,P.K; Swarup, G. & Sethi, C.L. (1970).
Heterodera zeae n. sp. (Nematoda :
length at pH 5.0 statistically decreased
Heteroderidae). A cyst forming nematode
over pH 7.0 however at pH 9.0 it was at par
from Zea mays. Nematologica. 16 : 511with pH 7.0. The hyaline tail terminus
516.
length was decreased significantly at both
pH 9.0 and 5.0 over pH 7.0. The maximum Sabeb. S. & Saxena, S.K (1988). Etlect of pH
on the morphometrics of Meloidogyne
tail length also significantly decreased at
incognita. International Nematol. Network
both pH 9.0 and 5.0 in comprasion to
newsl. 5 : 10-11.
neutral pH level.
Sheila, Hakim, Veena Pant & Saxena, S.K
Results on morphometries revealed
that cyst measurements i.v. cyst length,
cyst width, fenestrallength, fenestral width
(1985). Effect of different pH levels on root
knot development and morphometrics of
Meloidogyne incognita. IndianJ Nematol.
15: 60-61.
Accepted for publication, May, 1998