Copyright is owned by the Author of the thesis. Permission is given for
a copy to be downloaded by an individual for the purpose of research and
private study only. The thesis may not be reproduced elsewhere without
the permission of the Author.
HORTI C U LTURAL AND PHYSIO LOGICAL ASPECTS OF VIGO U R
CO NTROL I N APRICOT
(Prunus armeniaca L.) UNDER ORCHARD A N D
CO NTROLLE D ENVIRO NMENT CO NDITIONS
A thesis presented in partial fu lfilment
of the req uirements for the degree of
DOCTOR OF PHILOSOPHY ( Ph.D.)
in
Pomology and fruit tree physi o logy
at Massey University
New Zealand
KAZEM ARZANI
October 1 994
ii
ABSTRACT
In the absence of dwarfi ng rootstocks f or apricot, techni q ues whi c h reduce
vegetative g rowth are i mportant in the orchard management system . Studi es
were conducted in the o rchard and i n controlled environ ment (CE) room s i n
o rder to explore the horticultural and physi ologi cal responses of apri cot
(Prunus a rmeniaca
L.) to some vi gour control techni ques.
In the orchard i n the h u mi d cli mate of Palmerston North, New Zealand, f ive­
year-old vigorous 'Sundrop' apri cot trees on ' Golden Quee n ' peach seed l i n g s
t rai ned o n Tatu ra trelli s a t 1 000 o r 2000 tree ha· 1 we re used. The o bjectives
were : a). to eval uate the trees' responses to 0.5 and 1 .5 g. tree· 1 soil appli e d
Paclobutrazol ( P BZ) , dormant root-pruni ng and regu lated def icit i rrigation
( R D I ) ; b) . to identif y osmotic adj ustment in f ruits and leaves in response to
i nternal water stress. Two-year-old 'Trevatt' apricot in an aeroponi c sy stem in
C E rooms were used with the objecti ves: a). to exami n e the eff ects of root
cytoki ni n and endogenous ABA on shoot growth and whole plant physi ology;
b) . to study the mechani sm of adaptati on to hi gh water stress.
-�
In the orchard all treatments reduced vegetati ve growth. PBZ was more
eff ective than the other treatments, and the lower rate (0 .5 g . tree- 1 ) when
appli ed annually gave more unif orm growth reducti on . The root-pruni n g and
RDI had less eff ect, particularly i n the second season of study. The deep soi l ,
together with low temperature and evapo rati on , high rai nf all and h u m i d
conditions duri n g wi nter and early spri ng were li m iti ng f actors f o r R D I . T h e
i n h i bi tory eff ect of root-pruning was more persi stent o n wi der spaced trees. I n
close planted trees root length densi ty ( R L D ) declined with i ncreasi n g dept h ,
b ut roots were observed t o 1 . 6 m explored soi l depth . Root-pruni ng increased
R L D , but no treatments eff ect was observed on root weight densi ty ( RWD) i n
t h e explored soi l volume.
P BZ i ncreased d ry matter partiti oni ng i nto crop 1n both seasons on c lose
Abstract
iii
spaced trees, a n d fru it growth and final fruit size were increased without any
detrimental effect on fru it quality. In the second year PBZ advanced flowering
by 2-4 days, and increased fruit set, final fruit number, crop density and yield
effic iency. I n general RDI had no negative effects on flowe rin g , fruiting, yield
a n d final fruit size. I n the second year it generally en hanced floweri n g , fruit set
and fruit number. Root-pruning did not affect other flowering and yield
parameters, but reduced fru it size i n the first season. There was some
evidence of advanced fru it matu rity and i ncreased total soluble solids by a l l
applied treatments. Generally fruiting characteristics we re improved , a n d
vegetative g rowth red uced , more by PBZ than b y root-pruning a n d R D I .
P B Z t reated trees had the same water status as controls. Their net C 02
assimilation rate (A) and stomatal conductance (g5) were improved , and fro m
later stage I a n d during stages 1 1 and I l l of fruit g rowth fru it carbohydrates were
i n c reased . R D I and root-prun ing increased net C02 assimi lation rate (A) and
stomatal conductance (g5) on some occasions. Root-pruned trees developed
an increased internal water deficit in the leaves and fruits especially at the
t i m e of highest water demand during fru it stage I l l . There was evidence on
occasions i n RDI and root-prun ing of osmotic adj ustment in leaves and f (u its
m aintaining turgor (\f' P ) .
A n aeroponic system with intermittent misting gave good control of plant water
stress. When water stress was developed g radually plants were able to
m ai ntain their t u rgor at h igh i nternal water deficit (-2.2 and -3.0 M Pa of \f' xylem
a n d \f/1 respectively) . Osmotic adjustment occu rred in both partially and fully
expanded l eaves of all treatments, BAP combined with water stress showed
b i gger osmotic adjustment. Water stress reduced vegetative growt h , a n d
i n c reased root :shoot ratio. Shoot tip ABA increased a s water stress i ncreased.
BAP reduced the growth inhibition and rise in shoot ABA of water stressed
p lants, maintained net C02 assimilation rate (A) and stomatal conductance
(g5), and increased root: shoot ratio.
In the Name of ALLAH the Most Merciful the Most Beneficent
I dedic ate this thesis to :
My pa rents Haj Mohammad Hassan a nd Haj Fatemeh Arzani for their
patience a nd moral support; my wife Fatemeh Arzani for her patience,
support a nd encouragement, a nd my children Ali, Mohsen and Mina Arzani.
ACKNOWLEDGMENTS
In the name of Alla h the most gracious and most merciful. First of all praise
to Allah for giving me the ability to learn. This study would not have been
possible without the help of Allah s. w. t.
I would like to ex pre ss my dee pe st g ratitude a nd sincere thanks to my
s u per visors Dr. David Wood and Dr . Ste phe n L awe s for the i r g u idance ,
e nco u rage me nt and criticism. I am g rate fu l a n d i nde bte d to the ir patie nce ,
e nth usiastic e nco u rage me nt and co mme nts and close super visio n thr o ug hout
t he cour se of this study. The y ne ve r g ot tire d answer i ng my q ue stions a n d I
was pr ovide d with frie nd ly answe rs at any ti me t h at I nee de d the i r he lp. I
wou ld like a lso to ex pre ss my th anks to D r. H ug o Vare la-Ai vare z my e o­
s u pe rvisor (Compute r Ce ntre , Masse y U niver sity) for his d iscussion i n p l a n n i ng
t he ex pe ri me nts, dat a analysis and re vie wi ng the m anu script.
I wish to ex pre ss my tha nks to P rof. David C h a l me rs fo r his co m me nts a n d
d iscussion d u ri ng the fir st ye ar o f orchard study ( a s a e o-super visor ) and also
his comme nts o n the contr o l e
l d e n vir o nme nt ex pe ri me nt. I wo u ld like to thank
Dr. Hosse i n Be hboudian for his co m me nts on t he water re lations study and
re vie wing chapter s 2 and 6 of this the sis. I wish to thank D r. D avid Wo olle y for
his comme nts at the time of pre par i ng the p roposal for the cont rol le d
e nvironme nt study, his sugge stions on ABA a n alysis, and his re vie w and
c o m me nts on chapte r 7 are ack n owle dge d . I wish also to thank Dr . Ke ith
H ug he s for his assistance in r oot core sampling in the o rchard stu dy and his
c o m me nts on pre se nti ng the re su lts of root study and re vie wi ng chapte r 4.
T hanks are ex te nde d to M r. Bru ce M ackay for a n swe ri ng my q ue stions and
his sugge stions reg ar d i ng statistical analysis.
I g re atly appre ciate the he lp from the staff of the P lant G rowth U nit , e spe cially
M r. Ray Johnstone a nd Mr . Cha rle s Forbe s. The assistance of Mr . De an
Peg ler t h roug hout the orchard , g lasshouse and contro l e
l d e nvir on me nt
ex pe rime nts is gr ate fu l ly re cog n ise d . Thanks to Mr. G i e
l s Russe l l for his
Acknowledgments
vi
ex ce l le nt he lp in monitor i ng the aer oponic and hydr opo nic syste ms u se d . I
wou ld also like to ex pre ss my th ank s to t he staff of the F ru it C rops U n it for
the i r manage me nt of the ex per ime nta l tree s a n d t he ir assi stanc�/ i n summe r
p ru n i ng and h ar ve sting . I thank the manage me nt a nd staff of the Cr own
Re se ar ch I n stitute (Hort+ Re se ar ch) for org anising the climate rooms, i n
particular Mr s. L iz H allig an , Mr s. Linda Robi n son a n d M r. Le n R u by ,
o pe rations te chnician. I gre atly appre ci ate the Ag Re se ar ch (C R I) providi ng me
with climatolog ical data of t he ex per i me ntal site .
I a m ve ry g rate fu l to the staff and postgr aduate stude nts of the Plant Scie nce
De p art me nt for the ir he lp and pr oviding a fr ie n dly e nvi ronme nt thr oug hout t h i s
study. I wou ld me ntion part icular ly the fr ie ndship of P a u l Aust i n and G u i l le rmo
C ru z- Castillo, and g rate fu l ly acknowle dge the te chnical assistance of Coli n
Tod, Chr is Rawling to n , Jonathan Dix o n and H ug h Ne i lso n whe n I was wo rki ng
i n t he labor ato ry. I gre atly appre ciate d the as� istance of M i ke C urr ie i n
synthe sising ABA-BSA conjug ate .
The pre se nce of all the other Ir anian postgr aduate stude nts a n d t he ir fami l ie s
i n Palme rston North m ade my family a n d I fee l at home . lt is my ple asure to
t h a n k and wish the m a happy and pr ospe ro u s future .
I g rate fu l ly acknowle dge t he U niver sity of Tar biat- Modarre s and the M i n ist ry
of C u lture a n d H ig her Education of Ir a n , for awar di ng me the sch olars h i p to
u n de rtake this study.
A nd l ast , but ce rtai n ly not le ast , my since re thank s are d ue to my wife
Fate me h Ar zani fo r he r patie nce , su ppo rt a n d e nco ur age me nt t h ro ug hout my
study and he r ex ce l le nt e ffort to e d ucate o ur chi ldre n . The p atie nce , of my
sons Ali a n d Mohse n and my daug hte r M i n a a n d the ir e ncou rage me nt a n d
u n der standing have e ncour age d me t o cope with difficu ltie s.
TA BLE OF CONTENTS
A BSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ii
ACKNOWL E D G M E NTS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
v
TABL E OF CO NTE NTS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
vii
L I ST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvi
L I ST OF F I G U RES
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
xvii
L I ST OF PL ATES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxii
. . . . . . . . . . . . . . . . . . . . . . . . .
G L OSSARY OF ABBREVIATIONS
C HAPTE R O N E : G E N E RAL I NTRODU CTI O N AND OBJECTIVES
. . .
1
. . . . . . . . . . . . . . . . . .
5
. . . . . . . . . . . . . . . . . . . .
5
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
C HAPTER TWO: REVIEW OF L ITERATURE
2 . 1 G E N E RAL OVE RVI EW OF APR ICOT
2 . 1 . 1 Classification
.
2 . 1 .2 History and o rigin
2 . 1 .3 Ge ographic
re g ions
xxiv
.
I
.
.
.
.
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
Climatic re q u i re me nts and production
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 . 1 .4 Rootstocks, G rowing Habit and Training syste ms
2 . 1 . 5 Some re ce nt studie s on apricot
.
. . . . . .
6
. . . . . . . . . . . . . . . . . . .
8
2 . 2 MANA G I N G THE G ROWTH OF FRU I T TREES
2 .2 . 1 ROOT-P RU N I N G
5
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
10
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12
2.2 . 1 . 1 Effe cts of root-pruning on g rowth of fruit tree s . . .
13
.
2.2. 1 . 1 . 1 Re sp onse of roots to pruning
.
. . . . . . . .
2.2 . 1 . 1 .2 Re sponse of shoots to root-pruning
2.2 . 1 . 1 .3
Root:shoot
e quilibrium
.
ratio
and
.
. . . .
13
15
functional
. . . . . . . . . . . . . . . . . . . . . . .
16
2.2 . 1 . 1 .4 The e ffe ct on trunk cross se ctional a re a
(TCSA)
2 .2 . 1 .2
Effe cts
of
.
. . . . . . . . . . . . . . . . . . . . . . . . . .
root-pru n i ng
on
18
physiological
proce sse s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
2.2. 1 .2 . 1 Accumulation of mine ral n utrie nts
. . . . .
19
. . . . . . . . . . . . . . . . . .
19
2.2. 1 . 2 .2 Wate r re lations
.
.
Table of Contents
viii
2.2. 1 .2.3
P h otosynth esis
partitioning
and
assi m i l ate
. . . . . . . . . . . . . . . . . . . . . . . . 20
2.2. 1 .2.4 Flower initiation and fruit development . . . 2 1
2.2. 1 .3 Practical use of root-prun ing techniques . . . . . . . . 2 1
2.2. 1 .3. 1 Time and type of root-pruning . . . . . . . . .
22
2.2. 1 .3.2 The effect of root-prun i ng on fruit quality
and c ropping . . . . . . . . . . . . . . . . . . . . . . . 23
2.2.2 PACLOBUTRAZOL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.2.2. 1 Effects of PBZ on growth of fruit t rees . . . . . . . . .
25
2.2.2. 1 . 1 Response of roots to PBZ . . . . . . . . . . . 25
2.2.2 . 1 .2 Response of shoots to PBZ . . . . . . . . . .
26
2.2.2 . 1 .3 The effect on trunk cross sectional a rea
(TCSA) . . . . . . . . . . . . . . . . . . . .
. . . . . .
28
2.2.2.2 Effects of PBZ on physiological p rocesses . . . . . .
28
.
2 .2.2.2 . 1 Accumulation of mineral nutrients . . . . . . 28
2.2.2.2.2 Water relations . . . . . . . . . . . . . . . . . . . 29
2.2.2.2.3
Photosy n t h es i s
partitioning
and
ass i m i l at e
. . . . . . . . . . . . . . . . . . . . . . . . 29
2.2 .2.2.4 Flower i n itiation and fru it development . . .
30
. . . . . . . . . . . . . . . . . . . . .
31
. . . . .
34
2.2.2.3 Practical use of PBZ
2.2.2.3. 1 Type and timebf P BZ application
2.2.2.3.2 The effect of PBZ on fruit quality and
cropping . . . . . . . . . . . . . . . . . . . . . . . . . .
35
2.2.3 WATER STRESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
37
2 .2.3 . 1 Effect of water stress on g rowth of fru it t rees . . . . 4 1
2.2.3 . 1 . 1 The effect of water stress o n roots . . . . .
41
2.2.3. 1 .2 The effect of water stress o n shoot
g rowth
. . . . . . . . . . . . . . . . . . . . . . . . . . .
44
2.2.3. 1 .3 The effect of water stress on tru n k c ross
sectional area (TCSA) . . . . . . . . . . . . . . . . 45
2 . 2.3.2
Effects
of
water
stress
on
physiological
Table of Contents
IX
proce sse s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
45
2.2.3.2. 1 Accumulation of m i ne ral nutrie nts . . . . . .
46
2 . 2 .3.2.2 W ate r re lations . . . . . . . . . . . . . . . . . . .
47
2 .2.3.2.3
Photosynthe s is
partition ing
and
assi m i l ate
. . . . . . . . . . . . . . . . . . . . . . . .
53
2 .2.3.2.4 Flowe r i n itiation and fruit de ve lopme nt . . .
56
2 .2.3.2.5
The
e ffe ct
of
wate r
stre ss
on
e ndoge nous ABA . . . . . . . . . . . . . . . . . . . .
56
. . . . . . . . . . . . . . .
58
2.2.3.3. 1 Time and type of i mpose d wate r stre ss . .
59
2 .2.3.3 Practical use of wate r stre ss
2 .2.3.3.2 The e ffe ct of water stre ss on fru it qual ity
and yie ld . . . . . . . . . . . . . . . . . . . . . . . . . .
61
C HAPTE R T H R E E: ORCHARD EXP E R I M E NTS
G E N ERAL MATE R IALS AND METHODS
. . . . . .
63
3 . 1 I NTRO D U CTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
63
3.2 P LANT MATE R IAL, C U LTU RAL AND TRA I N I N G SYSTEM S
63
3 . 3 EXP E R I M E NTAL SITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
64
3.4 ENVI RONMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
64
3 .4 . 1 Climate
. . . . . . . . . . .' . . . . . . . . . . . . . . . . . . . . . . . . . .
64
3.4 . 1 . 1 Rainfall and Pan Evaporation . . . . . . . . . . . . . . .
66
3 .4 . 1 .2 Te m pe ratu re
. . . . . . . . . . . . . . . . . . . . . . . . . . .
66
3 . 4 . 1 .3 Sunshine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
66
3.4. 1 .4 Re lative hum id ity . . . . . . . . . . . . . . . . . . . . . . . .
66
3 .4.2 Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
66
3 . 5 D u ration and layout of the ex pe ri me nts . . . . . . . . . . . . . . . . . . . . .
67
3 .5 . 1 Close s pace d e xpe ri me nt . . . . . . . . . . . . . . . . . . . . . . . .
67
3 .5 . 1 . 1 Ex pe ri me ntal layout . . . . . . . . . . . . . . . . . . . . . .
67
3 .5 . 1 .2 Root-pruning tre atme nt . . . . . . . . . . . . . . . . . . . .
67
. . . . . . . . . . . . . . . . . .
68
3.5. 1 .3. 1 Type of application . . . . . . . . . . . . . . . . .
68
3 . 5 . 1 .3 Paclobutrazol tre at me nts
Table of Contents
X
3 . 5 . 1 .3.2 Dose and time of application . . . . . . . . .
68
3. 5 . 1 .4 Wate r stre ss tre atme nt . . . . . . . . . . . . . . . . . . . . 68
3.5.2 Wide space d e xpe rime nt . . . . . . . . . . . . . . . . . . . . . . . . . 69
3 . 5 . 2 . 1 Expe ri me ntal layout . . . . . . . . . . . . . . . . . . . . . .
69
3. 5 .2.2 Root-pruning tre atme nt . . . . . . . . . . . . . . . . . . . . 73
3.5.2.3 Paclobutrazol tre atme nts
. . . . . . . . . . . . . . . . . .
73
3.5.2.4 Wate r stre ss tre atme nt . . . . . . . . . . . . . . . . . . . .
73
C H A PTER FOU R : EFFECTS OF TR EATM ENTS O N VEG ETATIVE
G ROWTH OF ' S U N D RO P' A P R I COT . . . . . . . . . .
74
4 . 1 I NTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
4.2 M ATERIAL S A N D M ETHODS . . . . . . . . . . . . . . . . . . . . . . . . . . .
75
4.2. 1 Me asure me nts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
75
4 . 2 . 1 . 1 Summe r pruning· . . . . . . . . . . . . . . . . . . . . . . . .
75
4.2. 1 .2 Se asonal g rowth patte rn . . . . . . . . . . . . . . . . . . . 76
4.2. 1 .2 . 1 Shoot growth . . . . . . . . . . . . . . . . . . . . . 76
4.2 . 1 .2.2 De structive shoot and fru it harve st . . . . .
76
4.2 . 1 .3 Tru nk cross se ctional are a (TCSA) . . . . . . . . . . .
78
4.2. 1 .4 L ig ht within the canopy . . . . . . . . . . . . . . . . . . . .
78
4.2 . 1 .5 Root core sam pling
. . . . . . . . . . . . . . . . . . . . . .
79
4 .2.2 STAT I STICAL ANALY S I S . . . . . . . . . . . . . . . . . . . . . . . .
84
4 . 3 R E SU L TS : CL OSE PL ANTED TREES . . . . . . . . . . . . . . . . . . . . . 8 5
4.3. 1 Summe r p runing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
85
4 . 3. 1 . 1 1 990- 1 99 1 se ason . . . . . . . . . . . . . . . . . . . . . . .
85
4.3. 1 .2 1 99 1- 1 992 se ason . . . . . . . . . . . . . . . . . . . . . . .
86
4.3.2 Se asonal g rowth patte rn . . . . . . . . . . . . . . . . . . . . . . . . .
92
4.3.2 . 1 Shoot g rowth . . . . . . . . . . . . . . . . . . . . . . . . . . .
92
4 .3.2. 1 . 1 1 990- 1 99 1 se ason . . . . . . . . . . . . . . . . .
92
4.3.2. 1 .2 1 99 1 - 1 992 se ason . . . . . . . . . . . . . . . . .
92
4.3. . 2.2 De structive shoot and fruit harve st . . . . . . . . . . . .
93
(
4.3.3 Trunk cross se ctional are a (TCSA)
. . . . . . . . . . . . . . . . .
96
xi
Table of Contents
. . . . . . . . . . . . . . . . . . . . . . . . .
96
. . . . . . . . . . . . . . . . . . . . . . . . . . .
99
4.3.4 Light within the canopy
4 .3.2 Root characte ristics
.
.
4.3. 2 . 1 Root-le ngth de nsity (RLD)
.
4.3.2.2 Root-we ight de nsity ( RWD) .
. . . . . . . . . . . . . . . .
.
.
.
.
.
.
.
.
.
.
4 .4 RESU LTS : WIDE P LANTED TREES ( 1 990- 1 991 S EASON)
4.4. 1 S u m me r pru ning
4.4.2 S hoot g rowth
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
4.4.3 T r u n k c ross se ctional are a (TCSA)
4 . 5 D I SC U SSION
.
.
.
.
.
.
.
.
.
.
.
.
4. 5 . 1 Tree re sponse to PBZ
.
.
.
.
. .
.
.
.
.
.
.
4.5.2 Tree re sponse to root-pruning
4.5.3 Tree re sponse to RDI
S U M MARY
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. .
.
. .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
99
1 03
1 08
1 08
1 09
1 09
. 111
.
.
.
.
111
1 14
. 1 16
.
1 19
C HAPTER FIVE: EFFECTS OF T R EATMENTS O N REPRO D U CT I V E
G ROWTH OF ' S U N D ROP' APRICOT
5 . 1 I NTROD U CTION . .
.
.
.
.
.
.
.
.
.
5.2 MATE R IALS AN D METHODS .
5 .2 . 1 Me asure me nts
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
1 21
. . 1 21
.
.
.
.
.
.
1 23
1 23
5.2. 1 . 1 Flowe ring pe riod , flowe r and f; uit de n sity and fruit
se t
.
.
.
.
.
.
.
5 .2. 1 .2 F ru it g rowth
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. .
. . . . .
.
.
.
.
5 .2. 1 .2 . 1 Fruit vol ume -diame te r re lationship
5 . 2 . 1 .2.2 Se asonal fruit g rowth .
5.2. 1 .3 Y e
i ld and fruit quality
5 .2 . 1 .4 Partitioning inde x
5.2.2 STATIST ICAL ANALYSIS
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
5.3 RESU LTS: CLOSE PLANTED TREES
.
.
.
.
.
.
.
. .
.
.
.
.
.
.
. . . . .
.
.
.
.
.
.
.
.
.
.
. 1 23
. . . 1 23
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. . . . .
.
.
.
. .
.
.
.
.
.
1 23
. 1 24
.
.
.
.
.
. . .
.
.
.
5.3. 1 Flowe ri n g pe riod , fruit se t, flowe r and fruit de nsity
5.3.2 Se asonal fruit g rowth
.
1 25
1 26
1 29
. 1 30
1 30
1 30
5.3.2 . 1 Se ason 1 990- 1 9 9 1 . . . . . . . . . . . . . . . . . . . . . . . 1 35
xii
Table of Contents
5.3.2.2 Se ason 1 99 1 -1 992 . . . . . . . . . . . . . . . . . . . . . . . 1 36
5 . 3.3 Y ie ld and fru it qual ity
.
.
.
.
. .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
1 43
5.3.3. 1 Se ason 1 990- 1 99 1 . . . . . . . . . . . . . . . . . . . . . . . 1 43
5.3.3.2 Se ason 1 99 1 - 1 992 . . . . . . . . . . . . . . . . . . . . . . . 1 44
5 .3.4 Part itioning inde x .
.
.
.
.
.
.
.
5 . 4 RESU LTS: W I D E P LA NTED TREES
5.4. 1 Fruit g rowth
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
5.4.2 Y ie ld and fru it quality (1 99 1 data on ly)
5 . 5 D I SCU SSION .
.
.
.
. .
.
.
.
.
.
.
5.5. 1 Tree re sp onse to PBZ
.
.
.
.
.
.
.
.
.
.
S U M MARY
C HAPTER
.
.
.
.
SIX:
.
.
.
.
.
.
.
.
.
.
.
E FFECTS
.
.
.
.
.
.
.
.
.
.
.
.
.
5.5.2 Tree re sp on se to root-p run ing
5.5.3 Tree re sp onse to RDI
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
OF
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
TREATM E NTS
.
.
.
ON
.
.
.
.
.
.
.
.
.
.
6 .2 MATE R IALS AND M ETHODS
6.2 . 1 Me asure me nts
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
6 . 2 . 1 . 1 C l i matic conditions
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
6.2. 1 .2 Soil moisture me asure me nts .
6.2. 1 .3 Xyle m wate r p ote ntial (\fxylem)
.
.
.
.
.
.
.
.
.
.
.
.
.
1 45
1 54
1 54
1 55
1 63
1 65
1 68
1 69
1 70
WAT E R
RELATIONS O F ' SU NDROP' APRI COT
6 . 1 I NTRODUCTION
.
.
.
.
6.2. 1 .4 Le af p hotosynthe sis and stomatal conductance
.
�
.
.
1 72
1 72
1 75
1 75
1 75
1 75
1 77
1 78
6.2. 1 .5 Le af and fruit wate r p ote ntial, p re ss u re p ote ntial,
osmotic p ote ntial and le af re lative wate r conte nt
6.2. 1 .6 Fruit carbohydrate s
6.2.2 STATIST I CAL ANALYS I S
.
.
6.3 RESULTS: CLOSE SPAC ED TREES
6.3. 1 Climatic d ata
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. .
.
.
.
.
1 78
. 1 82
.
.
.
.
.
.
.
.
.
.
.
1 87
1 87
1 87
6.3. 1 . 1 Se ason 1 990- 1 99 1 . . . . . . . . . . . . . . . . . . . . . . . 1 88
6.3. 1 .2 Se ason 1 99 1 - 1 992
.
.
.
.
.
.
.
.
�·
.
.
.
.
.
.
.
.
.
.
.
.
.
1 88
Table of Contents
xiii
6.3.2 Soil moisture . . . .
.
.
. .
.
. . . . . . . . . . .
.
. . . . . . . . . . . . 1 93
6.3.2 . 1 Season 1 990- 1 991 . . . . . . . . . . . . . . . . . . . . . . . 1 93
6.3.2.2 Season 1 99 1 - 1 992 . . . . . . . . . . . . . . . . . . . . . . . 1 94
6.3.3 Xylem water potential
.
.
. . . . . . . . . . . . . . . . . . . . . . . . . 1 94
6.3.3 . 1 Season 1 990- 1 991
. . . . . . . . . . . . . . . . . . . . . . 1 94
6.3.3.2 Season 1 99 1 - 1 992 . . . . . . . . . . . . . . . . . . . . . . . 1 97
6.3.3.2 . 1 D i u rnal patte rn of xylem water potential . . 1 97
6.3.4 Net C02 assim ilation rate (A) and stomatal conductance
(g5)
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
1 98
6.3.4 . 1 Season 1 990-1 99 1 . . . . . . . . . . . . . . . . . . . . . . . 1 98
6.3.4.2 Season 1 99 1 - 1 992 . . . . . . . . . . . . . . . . . . . . . . . 1 98
6.3.4.2 . 1 Diurnal pattern of net C02 assim ilation
rate and stomatal cond uctance . . . . . . . . . . 1 98
6.3.5 Osmotic adjustment (Season 1 99 1- 1 992 only) . . . . . . . . . 206
6.3.5 . 1 Osmotic adj ustment of leaf . . . . . . . . . . . . . . . . . 206
6.3.5.2 Osmotic adjustment of fruit
. . . . . . . . . . . . . . . . 206
6.3.6 F ruit simple carbohyd rates (CHO) . . . . .
.
. . . . . . . .
.
. . . 212
6 .4 R E S U LTS: WI D E S PACED TREES (SEASON 1 990- 1 99 1 ON LY)
6.4. 1 Soil m oist u re . . . . .
.
. 215
. . . . . . . . . . . . . . . . . . . . . . . . . . . 215
6.4.2 Xylem water potential . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1 6
6.4.3 NetC 02 assim ilation rate (A) and stomatal conductance
(95)
•
•
•
•
•
•
•
•
•
•
•
•
6.5 D I SC U SSION . . . . . . . . . . .
•
.
.
.
•
•
•
•
•
•
. . . . . .
•
.
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
216
. . . . . . . . . . . . . . . . . . . 220
6.5. 1 Tree response to PBZ . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
6.5.2 Tree response to root-pruning . . . . . . . . . . . . . . . . . . . . . 2 2 1
6.5.3 Tree response t o RDI . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
S U M MARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
CHAPTER SEVEN : THE EFFECTS OF WATE R STRESS A N D
CYTOKI N I N O N VEGETATIVE G ROWTH,
WATER RELATIONS AND ENDO G E N O U S
Table of Contents
xiv
ABSC I S IC AC I D LEVEL OF 'TREVATI'
APRI COT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
7 . 1 I NTROD UCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
7.2 MATERIALS AND M ETHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 34
7.2. 1 Preliminary study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 34
7.2.2 Plant material (Main experiment) . . . . . . . . . . . . . . . . . . . 239
7.2.3 Experimental site and enviro nmental co nd itio ns
. . . . . . . . 240
7.2.4 Specificatio n of the aero po nic tanks and o pe ratio n of the
system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
7.2.5 Experimental l ayo ut and treatments applicatio n . . . . . . . . . 246
7 .2.5. 1 Co ntro l and 6-benzylamino pu rine (BAP) . . . . . . . . 247
7.2.5.2 WS ,WSb and BAP+WS . . . . . . . . . . . . . . . . . . . 247
7.2.6 Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
7.2. 6 . 1 Environmental co nditio ns . . . . . . . . . . . . . . . . . . 248
7.2.6.2 Xylem wate r po tential ('¥xylem) . . . . . . . . . . . . . . . 248
7.2.6.2 Shoo t g ro wth . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
7.2.6.3 Leaf pho to synthesis and sto matal co nd uctance . . 248
7.2.6.5 Destructive harvesting . . . . ., . . . . . . . . . . . . . . . 248
7.2.6.6 Leaf water po tential, pressu re po tential and
o smo tic po tential . . . . . . . . . . . . . . . . . . . . . . . . . 25 1
7.2.6.7 Leaf carbo hyd rates . . . . . . . . . . . . . . . . . . . . . . . 252
7.2.6.8 P reparatio n o f samples fo r minera l element
analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
7.2.6 .8. 1 Analysis o f K, Ca and Mg . . . . . . . . . . . . 254
7.2.6.8.2 Analysis of N and P . . . . . . . . . . . . . . . . 255
7.2.6.9 ABA analysis in shoo t tip using ELISA metho d . . . 255
7.2.6.9 . 1
Sampling
analysis
and
procedu re
prio r
to
. . . . . . . . . . . . . . . . . . . . . . . . . . 255
7.2.6.9.2 P reparatio n of purificatio n columns . . . . . 256
7.2.6.9.3 Purificatio n of sample extracts . . . . . . . . 256
7.2.6.9.4 ELISA assay material . . . . . . . . . . . . . . . 258
Table of Contents
XV
7.2.6.9.5 ELI SA assay pro cedure
7.2.6.9.6
Estimating
samples
7.3 STATI STICAL ANALYSIS
7.4 RESULTS
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. .
7.4. 1 Xylem wate r po tential (\.f'xylem )
7 .4.2 Shoo t g ro wth . . .
.
.
.
.
.
.
ABA
. . .
.
.
.
.
.
.
.
.
.
.
•
•
. .
.
.
.
. . . . . . .
.
.
.
.
.
co ntent
.
.
.
.
.
.
.
.
.
•
.
.
.
.
.
.
.
•
.
.
.
.
.
.
.
.
. . .
. .
.
.
.
.
.
in
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
•
.
.
.
.
. 259
plant
.
. . .
.
. .
. .
.
. .
•
.
.
. . 260
.
.
.
.
•
. . . .
.
.
.
260
264
264
266
7.4.3 Net C02 assi milatio n rate (A) and sto matal co nductance
(g5)
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
7.4.4 Dry matter partitio n ing (destructive harvest) . . . . . . . .
7.4.4. 1 Roo t to shoo t ratio
.
. . . . . . .. . . . . . .
.
.
.
.
•
.
.
.
.
.
.
.
.
7 .4.5 W ater po tent ial (\.f'1 ) , turgo r po tential (\.f'p) and o s mo tic
po tential {\.f's) . . .
.
.
.
. . . . . . . . . . . .
.
.
. .
.
. . . . .
7.4. 5 . 1 Fully expanded leaves (mature leaves)
.
.
.
7.4.5.2 Partially expanded leaves (yo un g leaves) . . .
7.4.6 Leaf simple carbo hyd rates (CHO) .
7.4.7 Minerals analyses
.
.
. .
.
. . .
.
. .
.
.
.
.
.
. . . .
. . . . . .
.
.
.
. .
.
.
. . .
.
.
.
.
.
.
.
.
.
.
•
•
268
. . 268
.
. 271
. . 27 1
.
. 277
. . 277
.
. 277
. . 279
7 .4.8 ABA determinatio n in shoo t tip and partially expanded
leaves using E L I SA
7.5 D I SC USSION
S ummary
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. . . .
.
.
.
.
. .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
..
.
.
.
.
.
.
. .
.
.
.
. .
.
.
.
.
C HAPTER E I G HT: G E N ERAL D I SCUSSION AND CONCLUSION
8 . 1 P ractical and beneficial aspects of co ntro lling vigo u r .
8 .2 Physio lo g ical aspects of co ntro l ling vigo u r . .
.
.
. . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
REFE RENCES ...
.
.
.
.
.
.
.. .
.
.
.
.
.
.
.
.
.
.
.
.
.
. . .
.
.
.
.
.
. .
.
.
. . .
. . .
.
.
.
.
.
.
.
.
.
.
. .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
283
. 283
.
295
297
. . 299
.
8.3 So me po ssible directio ns fo r future research related to this study .
APPEN DICES
.
.
. .
.
.
. 306
.
.
.
.
.
.
.
31 3
315
317
LIST OF TA B LE S
Tab le 2 . 1 Eco no m ic e valuatio n o f paclo butrazo l in a pe ach o rchard . . .
32
Tab le 2.2 Summary of co ntributing facto rs that infl ue nce wate r
mo ve me nt fro m so il to plant . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Table 4. 1 . The arrange me nt fo r dividing e xplo re d so il vo l u me s into
s u b-vo l ume s fo r mo n ito ring RLD and RWD in roo t study . . . . . .
85
Tab le 4.2. The e ffe ct of tre atme nts o n trunk c ro ss se ctio n al a re a
(TCSA) o f 'Sundro p' aprico t during 1 990- 1 991 and
1 99 1 - 1 992 se aso ns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
97
Table 4 . 3 . Roo t le ngth de nsity (RLD) and roo t we ight de nsity (RWD)
fo r the who le so il vo l u me . . . . . . .
.
.
. . . . . . . . . . . . . . . . . . . . 1 04
Tab le 5 . 1 . The to tal n umbe r o f fru its re co rde d 59 days afte r full
b loo m on clo se space d tree s in 1 990- 1 991 and 1 99 1 - 1 992 . . . . 1 32
Tab le 5 . 2 . Fruit n umbe r, yie ld and fruit size o f harve ste d fruit in 1 99 1 . . 1 49
Table 5.3. Fruit numbe r, yie ld and fru it size o f harve ste d fruit in 1 992 . . 1 50
Table 5 .4. Fruit co lo u r ( H ue angle ) re co rde d in 1 99 1 and 1 992 . . . . . . 1 5 1
Table 5 . 5 . Fruit co lo u r (lightne ss) re co rde d in 1 99 1 and 1 992 . . . . . . . 1 52
Table 5 . 6 . To tal so luble so lids o f fru its at harve st in 1 99 1 and 1 992 . . . 1 53
Table 5 . 7. The to tal n umbe r o f fruit o n wide plante d tree s
re co rde d 59 days afte r fu l l bloo m in 1 99 1 and 1 992
. . . . . . . . . 1 56
Table 5 . 8 . Fruit numbe r, yie ld and fru it size o f harve ste d fruit
o n wide space d t ree s in 1 99 1
. . . . . . . . . . . . . . . . . . . . . . . . . 1 58
Table 5 . 9 . Fruit co lo u r ( H ue angle and Li ghtne ss) fro m wide
space d tree s re co rde d at harve st i n 1 99 1 and 1 992
. . . . . . . . . 1 61
Table 5 . 1 0. To tal so luble so l ids of fruits o n wide space d
t ree s at harve st i n 1 99 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 62
Table 6. 1 . The cate go risatio n o f so i l vo lume in mo n ito ring so i l
mo isture d u ring the o rchard e xpe rime nt d u ring the
1 990- 1 99 1 and 1 99 1 - 1 992 se aso ns . . . . . . . . . . . .
.
. . . . . . . . 1 87
Table 7 . 1 . The e ffe ct o f t re atme nts o n a). Ne t C02 assimilatio n rate (A)
and b) . Sto matal co nd uctance (g5) o f ' Tre vatt' aprico t in
the ae ro po n ic syste m and co ntro lle d e nviro nme nt co nditio ns . . . 269
L I ST OF FIGUR ES
Figure 2 . 1 Schematic diagra m of the develo pment of p lant water
deficit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1
Figure 2 . 2 Reg u lated deficit i rrigation (RDI) applied d u ring
pi t hardening of yo ung high-density peach t rees . . . . . . . . . . . . 60
Figure 2.3 The period of accumulatio n o f shoo t and fruit
g rowth of 'Golden Queen' peach and 'Bartlett' pear . . . . . . . . . .
60
Figu re 3 . 1 The means of 30 yea rs ( 1 964- 1 994) mo nthly cl imatic
data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Fig u re 4.1 The dry weight o f shoot reg ro wth removed i n summer
p runing on close planted trees in 1 990- 1 99 1 and 1 99 1 - 1 992
seaso ns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 8
Fig u re 4.2 The effect o f treatment o n distribut ion o f summer
reg rowth and mean sho ot length (227 dafb) in 1 990- 1 991
season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Figu re 4.3 The d ry weight of shoot regrowth remo ved i n
different canopy zo n es in summer pruning i n 1 990- 1 991
and 1 99 1 - 1 992 seasons
.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Fig u re 4 .4 The effect o f treatments o n mean sho ot length
(2 1 3 dafb) , and d istribution of prunings preharvest
( 1 0 1 dafb) and postharvest (2 1 3 dafb) in 1 99 1 - 1 992
seaso n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1
Fig u re 4.5 The effect o f different vi gour co ntro l techn iq ues
o n cumulative shoo t g rowth in 1 990- 1 99 1 and 1 99 1 - 1 992
seasons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
94
Fig u re 4.6 The pattern of n ew g rowth (shoo ts and fruits)
throughout the 1 99 1 - 1 992 seaso n, determined by
destructive harvests
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
95
Fig u re 4.7 The relative light intensity i n different reg io ns
down the canopy i n 1 99 1 - 1 992 seaso n . . . . . . . . . . . . . . . . . . .
Fig u re 4 . 8 Coo rd inates o f fine ro ot (< 1 . 5 m m diam . ) samples
classified by RLD (0, <0.2 and >0.2 cm/m 3 of so il) . . . . . . . . .
.
98
. 1 00
List of Figures
xviii
Fig u re 4.9 Pro po rtio n o f samples with in selected regio n s o f
the roo t system wh ich co ntained fine roo t (<1 .5 m m diam . ) ,
based o n R L D data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0 1
Figure 4 . 1 0 Effect o f treatments o n cumulative pro po rtio ns o f
sample co res by RLD (cm. cm-3 ) . . . . . . . . . . . . . . . . . . . . . . 1 02
.
Figure 4 . 1 1 Coo rdinates o f woo dy roo t (> 1 . 5 m m diam.) samples
c lassified by RWD (0, < 1 .5 and > 1 .5 gram/cm 3 of so il) . . . . . . . . 1 05
Figure 4 . 1 2 Pro po rtio n o f samples within selected regio ns o f
the roo t system wh ich co ntained woo dy roo t ( > 1 .5 m m diam . ) ,
based o n RWD data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 06
Figure 4. 1 3 Effect o f treatments o n cumulative pro po rtio ns o f
sample cor es by RWD (g. cm-3 ) o f woo dy roo ts . . . . . . . . . . . . . 1 07
Figu re 4. 1 4 The effect o f treatment o n shoo t length (middle
cano py zo ne) and pruning on wide planted trees in
1 990- 1 99 1 seaso n
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
F i g u re 5 . 1 I nfluence o f fi rst seaso n treatments o n seco nd seaso n
flo wering and fru iting o f clo se spaced ' Sundro p' aprico t . . . . . . . 1 3 1
Figure 5.2 Relat io nships between a) . fru it diameter and measured
fru it vo l u me , and b). fruit diameter and measured fruit
fresh weight . . . . . . . . .
.
. . . . .
.
. . . . . . . . .
.
. . . .
.
. . . . . . . 1 33
Figure 5.3 Relatio nships between a) . measured fru it vo lume and
predicted fru it vo l um e and b). measured fru it fresh weight
and predicted fruit fresh weight . . . . . . . . .
.
. . .
.
. . .
.
. . . .
.
. 1 34
Figu re 5 .4 C u m u l ative increase in fru it diameter in 1 990- 1 99 1
and 1 99 1 - 1 992 seaso ns
.
.
.
.
. . .
.
.
.
. . . . . . . . . .
.
. . . . . . . . 1 38
Figure 5.5 I nfl uence o f treatments o n fruit vo lume in 1 990- 1 991
seaso n . . . . . . . . . .
.
.
.
. . . . . . . .
.
.
.
. . . . . . . . . . . . . . . . . . 1 39
Fig u re 5 .6 I nfluence o f treatments o n fruit vo lume in 1 99 1 - 1 992
seaso n . . . . . . . . . . . . . .
.
. .
.
. . . . .
.
.
.
.
. . . . . . . . . . . . . . . 1 40
Figu re 5.7 Seaso nal changes in fru it size o n the upper and
lo wer cano py zo nes in 1 990-1 991 seaso n
. . . . . . . . . . . . . . .
.
141
List of Figures
xix
Figu re 5 . 8 The influence o f treatments o n fruit dry weight and
p ro portio n reco rded fru it ha rvest .
.
. . . .
.
. . . .
.
. . . .
.
. . . . .
.
. 1 42
Figu re 5 . 9 The influence o f t reatme nts o n yield parameters
i n 1 990- 1 99 1 seaso n . .
.
.
.
. . .
.
. .
.
.
.
. . . .
.
.
.
. . .
.
.
.
. . .
.
.
1 46
Fig u re 5 . 1 0 The infl uence o f treatments o n yield parameters
i n 1 99 1 - 1 992 seaso n .
.
.
.
.
.
. . . . . . . .
.
. .
.
.
.
.
. . . . .
.
. .
.
.
. 1 47
Figu re 5 . 1 1 The effect o f treatments o n partitio n ing index ( P-index)
and annual increase in trunk cro ss sectio nal area
. . . . . . . . . . 1 48
Figu re 5 . 1 2 Seaso na l changes in fruit size o n wide planted
t rees in 1 990- 1 99 1 seaso n
. . . .
.
. . . . . . . . . .
.
.
.
.
. . . . .
.
.
.
1 57
Figu re 5 . 1 3 The influence o f t reatments o n fru it weight and
p ro po rtio n of wide planted trees reco rded at fru it
harvest fro m middle cano py zo ne . . .
.
.
. .
.
.
.
.
.
. .
.
. .
.
. .
.
.
.
1 58
Figure 5 . 1 4 The infl uence o f t reatments o n yield parameters
o f wide planted trees in 1 990- 1 99 1 seaso n . .
.
.
.
.
. . . . . .
Fig u re 6 . 1 The mo nthly climatic data fo r the 1 990- 1 99 1 seaso n . .
.
.
.
.
.
.
.
1 60
. 1 89
Figu re 6.2 Daily rainfal l and pan evapo ratio n during 1 990- 1 99 1
seaso n . . . .
.
.
.
. .
.
.
.
.
.
. . .
.
.
.
.
. . . .
.
. . . . . . .
.
.
. . . .
Figure 6.3 The mo nthly climatic data fo r the 1 99 1 - 1 992 seaso n . .
.
.
.
.
.
.
.
1 90
1 91
Figure 6.4 Daily rainfall and pan evapo ratio n during 1 99 1 - 1 992
seaso n . . . .
.
. .
.
. . .
.
. .
.
. . . . . . . . . . . . . .
.
.
.
.
. . . .
.
.
.
.
.
1 92
Figu re 6.5 The influence o f t reatments o n so il water co ntent (mm)
of clo se spaced 'Sundro p' du ring 1 990- 1 99 1 seaso n .
.
. . . . .
.
. 1 95
Figu re 6 . 6 The influence o f treatments o n so il water co ntent
(mm) o f c lo se spaced 'Sundro p' d u ring 1 99 1 - 1 992 seaso n .
.
. . . 1 96
Figu re 6.7 The i nfluence o f treatments o n xylem water po tential
(\f'xylem ) in 1 990- 1 99 1 seaso n . . . . . . . . . . . . .
.
.
.
. . . . . .
.
.
. . 1 99
F i g u re 6.8 The influence o f treatments o n xylem water po tential
(\f'xylem ) in 1 99 1 - 1 992 seaso n .
.
.
. .
.
.
.
. . . . . .
.
. . . .
.
.
. .
.
.
.
200
F igu re 6.9 The influence o f t reatments o n diurnal pattern s o f
xylem wate r po tential (\f' xylem) in 1 99 1 - 1 992 seaso n .
.
.
.
. .
.
. .
.
201
List of Figures
XX
Fig u re 6 . 1 0 The i nfluence o f treatments o n sto matal
co nductance (g5) and net C02 assimilatio n rate (A) in
1 990- 1 99 1 seaso n
. .
.
. . . . . . . . . .
.
.
. . . . . . . . . .
.
.
. .
.
.
. . 202
Figure 6. 1 1 The influence o f treatments o n sto matal
co nductance (g5) and net C02 assimilatio n rate (A) i n
1 99 1 - 1 992 seaso n
.
.
.
.
.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Fig u re 6. 1 2 The influence o f treatments o n d i u rnal patterns o f
n et C02 assimilatio n rate (A) o f clo se spaced t rees in
1 99 1 - 1 992 seaso n
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 04
F i g u re 6. 1 3 The influence o f treatments o n d i u rnal patterns
o f sto matal co nductance (g5 ) of clo se spaced t rees in
1 99 1 - 1 992 seaso n
. . . . . . . . . . . . . . . . .
.
. . . . . . . . . . . . . . . 2 05
F i g u re 6 . 1 4 The influence o f treatments o n p redawn leaf water
relatio ns of clo se spaced trees i n 1 99 1 - 1 992 seaso n . . . . . . . . . 2 07
Figu re 6. 1 5 The i nfl uence o f treatments o n m idday leaf water
relatio ns o f clo se spaced trees in 1 99 1 - 1 992 seaso n . . . . . . . . . 208
Fig u re 6. 1 6 The changes o f relati ve water co ntent, o smo tic
po tential and meas u red simple carbo hydrates d u ring
1 99 1 - 1 992 seaso n
.
.
.
.
.
. . . . . . .
.
. . . . . . . . . . .
.
. . . . . . .
.
209
Fig u re 6. 1 7 The i nfluence of treatments o n p redawn fru it water
relatio ns o f clo se s paced trees in 1 99 1 - 1 992 seaso n .
.
. . . . . . . 210
Fig u re 6. 1 8 The influence o f treatments o n m idday fru it water
relatio ns of clo se spaced trees in 1 99 1 - 1 992 seaso n
.
. . . . . . . . 21 1
Fig u re 6. 1 9 The influence of treatments o n seaso nal co ncentratio n
o f fruit simple carbo hyd rates d u ring 1 99 1 - 1 992 seaso n . . . . . .
.
213
Figure 6.20 The i nfluence o f treatments o n seaso nal patterns o f
co ncentratio n o f fruit simple carbo hydrates during
1 99 1 - 1 992 seaso n
. . . .
.
. . .
.
.
. . . . . . . . .
.
.
. .
.
. .
.
. . . . . . 214
Fig u re 6.21 The influence o f treatments o n so il water co ntent ( m m)
o f wide spaced ' Su nd ro p' d u ri ng 1 990- 1 99 1 seaso n . . . . .
F i g u re 6.22 The influence o f treatments o n xylem water po tential
.
. . . 217
List of Figures
xxi
(\}1xylem ) i n wide spaced trees in 1 990- 1 991 seaso n . . . . . . . . . . 2 1 8
Figure 6 . 23 The influence o f treatments o n sto matal
co nductance (g5 ) and net C0 2 assimilatio n rate (A) o f
wide planted 'Sundro p' in 1 990- 1 99 1 seaso n
. . . . . .. . . ... . . 2 1 9
Figure 7. 1 Clim atic enviro nment o f climate roo ms d u ring
experiment . . . . .. . ... . .. . . . . . . .... . .. . . . . . . ... . . . . 243
Figure 7.2 Typical standard curves used fo r dete rminatio n o f
abscisic acid (ABA) in the plant extract samples using E L I SA
. . 263
Figure 7.3 a). Xylem water po tential respo nse o f ' Trevatt' a prico t
to different treatments. b) . misting o ff-ti me and o n-time
(min utes) o n water stress t reatments . . . . . . . . . . . . . . . . .. . . 265
Figu re 7.4 The effect of d ifferent treatments o n shoo t g ro wth
o f 'Trevatt' aprico t . . . . . . . . . . . . . . . . . .. . . . . . . .. . .... . . 267
Figure 7.5 The infl uence o f treatments o n distributio n of plant
d ry weight of 'Trevatt' apricot at vario us dates . . . . . . . . . . . . . . 272
Figure 7.6 The effect o f t reatments o n plant parameters o f
' Trevatt' aprico t g ro wn i n a n aero po nic system . . . . . . . . . . . .. 273
Fig u re 7.7 The effect of t reatments on dry matter partitio n ing
in ' Trevatt' aprico t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
Figure 7.8 The effect o f treatments o n leaf water status o f
'Trevatt' aprico t
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . .. 278
Figu re 7 . 9 The effect of treatments o n fully expanded leaf
s i mple carbo hyd rates o f ' Trevatt' aprico t , by type
. . . . . . ... . . 280
Figu re 7. 1 0 The influence o f treatments on simple carbo hyd rates
o f 'Trevatt' aprico t, by treatment . . . . . . . . . . . . . . . . . . . . . . . . 2 8 1
Fig u re 7 . 1 1 The influe nce o f treatments o n m ajo r elements o f
fu lly expanded 'Trevatt' ap rico t leaves . . . . . . . . ... . . . . . . . . 282
Fig u re 7. 1 2 The i nfluence of t reatments on endo geno us abscisic
acid (ABA) o f terminal buds and two adjacent partially
expanded leaves i n ' Trevatt' aprico t ... . .. . . . . . . . .. . .. . . . 284
LIST OF PLATES
P late 2. 1 Huge apricot seedlings cv. 'Mech Mech' in a Tun isian
oasis in North Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
P late 3 . 1 'Sundrop' apricot trees in the close planted experiment
t rained to a Tatura trellis system
. . . . . . . . . . . . . . . . . . . . . .
70
P late 3.2 Application of treatm ents in orchard experim ent . . . . . . . . . . 7 1
P late 3.3 Root-pruning
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
P late 4 . 1 A close planted 'Sundrop' apricot t ree after destructive
shoot and fruit harvest, 1 99 1 - 1 992 season . . . . . . . . . . . . . . . . 77
P late 4.2 Root core sampling from close planted t rees a). S electing
position; b) . Driving tube i nto the soil . . . . . . . . . . . . . . . . . . . .
81
P late 4.3 Root core sampling from close planted t rees. a) . Root
core extraction; b) . Sectioning the soil column . . . . . . . . . . . . . .
82
P late 4.4 Washing out root sam ples using a semi-automated root
washi n g machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
83
P late 5. 1 . Non-destructive fruit growth measurement on close
spaced 'Sundrop' apricot trees d u ring 1 990- 1 99 1 season . . . . . . 1 27
P late 5.2. Wide planted 'Sundrop' trees at the tim e of fru it harvest . . . . 1 28
Plate 6. 1 I nstalling alum in um tubes for recording soil m oistu re . . . . . . . 1 76
P late 6.2 a) . Recording soil moisture using a neutron hydroprobe;
b). Using a stream of nitrogen gas to rem ove ethanol from
fru it extracts for carboh yd rate determination . . . . . . . . . . . . . . . 1 84
P late 6.3 a) . Fi ltering fruit carbohyd rate sam ples using Nylon
M em b rane Filter prior to i nj ection into high pressu re liquid
ch romatog raphy system; b) . H PLC . . . . . . . . . . . . . . . . . . . . . . 1 85
Plate 6.4 a) . R ecording '¥1 and '¥5 of sam ples using Wescor H R-33T . . 1 86
Plate 7. 1 P reliminary study with 'Sundrop' apricot seedlings i n an
aeropon ic system u nder g lasshouse conditions . . . . . . . . . . . . . 236
P late 7.2 a) . Visual checking of 'Sundrop' seedlings g rown i n a
hydroponic system in the prelim inary study with differen t BAP
levels; b). After 4 weeks treatm ent, control and 5 ppm BAP . . . . 237
P late 7.3 a) . 'Sundrop' apricot seed lings as used for p reliminary
List of Plates
xxiii
studies; b) . After 4 weeks treatm ent, control and 25 ppm BAP . . 238
Plate 7.4 Two-years-old 'Trevatt' apricot with plum rootstock in the
aeroponic tanks in the controlled envi ronm ent room s . . . . . . . . . 241
Plate 7.5 ' Trevatt' apricot (control) in an aeroponic system in
controlled environm ent conditions, 84 days after establishm ent
(57 dats) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Plate 7.6 Xylem water potential (\}'xylem) m easu rem ent to check and
adjust the level of water stress on ' Trevatt' apricot . . . . . . . . . . . 249
Plate 7. 7 The response of trees was checked frequently by visual ly
inspecting the shoots and root system
. . . . . . . . . . . . . . . . . . . 250
Plate 7.8 Sam pling shoot tip and adjacent partially expanded leaves
for ABA analysis, and fully expanded leaves for sim ple
ca rbohyd rates and m ineral analysis of 'Trevatt' apricot
Plate 7.9 a) . Measu rem ents of \}' 1 and
\}' s
. . . . . . . 253
of partially expanded leaves
and m at u re leaves usi ng the dew point m ethod. b) . P reparation
of PVP and Sephadex col um ns for ABA analysis
. . . . . . . . . . . 261
Plate 7 . 1 0 a) . Sephadex colum ns after pu rification of sam ple
extracts for ABA analysis (insert: Sep-Pak cartridge colum n) ;
b) . Measurem ent of sam ple absorbance at 41 0 nm using
Dynatech M icroplate Reader Model, MR 5000/7000
. . . . . . . . . 262
Plate 7. 1 1 Final destructive harvest (57 dats) of aeropon ical ly g rown
'Trevatt'. a). BAP+WS and b) . BAP treatm ents . . . . . . . . . . . . . 2 75
Plate 7. 1 2 Final destructive harvest. a) . control and b) . WS t reatm ents . 276
Plate 8. 1 Mature sweet cherry orchards in two different clim ates and
planting system s. a) . A high density o rchard using P BZ as a
vigour control tech nique (South I slan d , New Zealand) . b).
: Km east of Teh ran) . . 304
Typical I ran ian wide planted orchard (::::50
G LOSSARY OF ABBR EVIATI O N S
A
2
net C02 assim i lation rate ().l.m ol m · s· 1 )
ABA
abscisic acid
a.i.
active i ngredient
BAP
6-benzylam inop u rine
BAP+WS
6-benzylam inopurine with water stress induced by interm ittent
m isting
BSA
bovine serum album in
CE
controlled environm ent
CD
2
crop density (fru it n um ber cm· TCSA)
CHO
carbohyd rate
CV.
cu ltivar
Cu lta�
Paclobutrazol form u lation
dafb
days after fu l l bloom
dae
days after establishm ent
dats
days afte r treatm ent started
DW
Dry weight
DWI
DWI I
DWI I I
stage I of fru it g rowth based on dry weight
stage 11 of fruit g rowth based on dry weight
stage I l l of fruit g rowth based on dry weight
EC
electrical conductivity (m S)
ELl S A
enzym e linked imm unosorbent assay
Eps
Epan
ETcrop
ET
FC
FGR
FT1
FT2
evaporation over the planting sq uare
pan evaporation
crop water req u i rem ent (mm day- 1 )
evapotranspiration
field capacity
fruit g rowth rate (mm , g. or cm 3 day- 1 )
fruit size at tim e 2 (mm , cm 3 or g.)
fru it size at tim e 1 (mm ,
FW.
initial fresh weight (g) ,
GA
g ibbe rellic acid
3
r.-.,--
o r g.)
Abbreviations
GLM
XXV
General Linear Mode l
gs
2
stom atal conductance (m m ol m· s· 1 )
H- PBZ
high rate of Paclobut razol ( 1 .5 g tree - 1 )
H P LC
high per form ance l iquid chrom atog raphy
IAA
indole-3-acetic acid
IC l
Im perial Chem ical Ind ustries Ltd
2
water flux density (g m · s- 1 )
J
.
L
LAR
Q
l ightness ( refers to colou r)
total root length (cm ) ( refers to root study)
leaf area ratio ( ratio of total leaf area to whole plant d ry weight,
2
m g· 1 )
L-P BZ
low rate of Paclobutrazol (0.5 g t ree- 1 )
M Ab
Monoclonal antibody
M Pa
m ega pascal ( 1 Mpa
NF
NFT
NZ
n molcho
=
1 0 bar)
total n um ber of fru its at the tim e of fruit harvest
n utrient film technique
m oles of sol ute ( refers to Van't Hoff's equation)
N ew Zealand
PBZ
Paclobutrazol
P.E.
pan evaporation
PEG
polyethyle ne glycol
P-index
2
partitioning index (kg yield cm · TCSA ye ar" 1 )
PNP
p -n it rophenyl phospr. ate
P P3 33
paclobutrazol
PPF D
2
photosynthetic photon fl ux density (J.lm ol m · s· 1 )
PVP
I nsoluble Polyvinylpyrrolidone
R
the u n ive rsal gas constant ( refers to Van't Hoff's eq uation)
r
d istance from tree ( refers to root study)
RCBD
RDI
r
resistance to d iffusion of water between \f'w 1 and \f' w 2
random ized com plete block design
reg u late d deficit i rrigation
Abbreviations
R dwt
xx vi
d ry we ight o f fine o r woo dy roo ts (g)
Re lative hum idity (%)
RH
roo t-le ngth de nsity (cm o f roo ts cm-3 of so il)
R LD
RM
re pe ate d me asu re me nt analysis
R PM
re vo lutio ns minute_,
RWD
roo t-we ight de nsity (g o f roo ts cm-3 o f so il)
re lative wate r co nte nt (%)
R WC
S avant
auto matic Spee dvac co nce ntrato r
TSS
to tal so l uble so lids
T
fruit te m pe ratu re in °K ( re fe rs to Van't Ho ff's e quatio n)
TBS
buffe r co ntaining Tris, MgCI2 and N aCI
TBST
wash ing buffe r TBS co ntain ing 0. 05% (v/v) Twee n 20, and 0 . 1 %
(w/v) BSA
T2
time 2 (day)
T,
time 1 (day)
TCSA
2
tru n k cro ss se ctio nal are a ( cm )
TCSA GR
2
g ro wth rate o f trunk cro ss se ctio nal are a (cm ye a r" 1 )
TCS� 2
TY
&
t1
TCSA re co rde d at time 2 (t2) and time 1 (t, )
to tal harve ste d fruit tree_, (g.)
TW
t u rgid we ight (g)
V
vo l u me of so lve nt in litre s ( re fe rs to Van't Ho ff' s e quatio n)
so i l sample vo lume (cm 3 ) ( re fe rs to roo t study)
vo
V
o smo tic vo l u me at fu l l turgo r
VPD
vapo u r pre ssure de ficit (mb)
WS
wate r stre ss induce d by inte rm itte nt m isting
WSb
wate r stre ss induce d with inte rmitte nt m isting (see 7.2.5.2)
2
yie ld e fficie ncy (g. o f fruit cm- TCSA)
YE
'Pcho
z
'1',
de pth to m idpo int o f sample ( re fe rs to roo t study)
o smo tic pre ssure (M Pa) o f e ach individual re co rde d carbo hyd rate
( re fe rs to Van't Ho ff' s e quatio n)
fru it wate r po te ntial
Abbreviations
xxvii
'¥ 9
g ravitational potential
'l'91ucose
osm otic pressu re of g lucose (the partial contribution
glucose in osm otic adjustm ent)
'¥ 1
'I'm
'l'P
'I's
'I'so
'I'w
.6. 'I'w
'I'xy lem
e
leaf water potential
m atric potential
tu rgor or pressu re potential
osm otic potential
osm otic potential at fu ll turgor
water potential
water potential difference between two points ('I'w1 - 'I'w2 )
xylem water potential
angle relative to row direction ( refers to root study)
of