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Preharvest Practices Affecting Postharvest Quality of

'Hayward' Kiwifruit

A thesis presented in partial fulfilment of the requirements for the degree of

DOCTOR OF PHILOSOPHY

In

Plant Physiology and Horticultural Science

Massey University, New Zealand

Katrina Norah Buxton

November 2005

Abstract

Repeat purchase of kiwifruit is primaril y driven by consumer judgement of internal fruit quality

attributes, including those affected by dry matter concentration (DMC) and mineral composition i n

fruit . Thi s research investigated mechanisms affecting carbohydrate, mineral and water

accumulation in 'Hayward' kiwifruit (A ctinidia deliciosa), and related these to specific

management practices. Canopy manipulation through pruning and treatments such as artificial

pollination, defoliation, girdling, thinning and application of the auxin transport inhibitor TIBA,

may affect fruit DMC and mineral composition.

Leaf photosynthesis and fruit dry matter concentrations (DMC) started to decline as leaf area i ndex

values increased above 3-4. In addition to reducing competition for carbohydrates between

vegetative and reproductive growth, leader pruning probably increased DMCs of fruit in the leader

zone by improving l ight interception. Photosynthesis was not affected by crop loads between 20-

60 fruit m-2, but was consistently h igher on non-terminating (long) shoots than on terminating

( short) shoots, as were fruit DMCs . Differences in photosynthetic rate of leaves on these two

shoot types were attributed to differences in shoot exposure to the sun, and also to the greater

demand for carbohydrate within long shoots.

Leaves subtending fruit may increase Ca, and to a lesser extent Mg, flow into fruit, however their

accumulation was not affected by leaves outside the fruiting shoot. Xylem sap Ca and Mg

concentrations were higher in shoots with a high rather than a low leaf: fruit (L:F) ratio and this

may, at least partially, relate to the increase in shoot transpiration that occurs as shoot L:F ratios

increase. Within vine variation i n fruit Ca concentrations may reflect variations in xylem sap flow

rates and Ca concentrations of xylem sap reaching fruit.

Calcium translocation may occur i ndependently of ion movement in the transpiration stream.

Timing and extent of vascular differentiation in flower and fruitlet pedicels, possibly regulated by

auxin, may influence fruit Ca accumulation. It i s l ikely that early differentiation of vascular tissue

in flower and fruitlet pedicels influenced cell division and subsequent (carbohydrate) sink strength

of frui t by determining availabil i ty of carbohydrate for partitioning into cel l wal ls .

While growers have the potential to induce minor changes in fruit DMC, further increases wi l l

depend on the separation of carbohydrate and water accumulation . Further research is required to

elucidate the mechanisms regulating phloem transport and unloading of sucrose in kiwifruit.

1Jl

Acknowledgements

I can't believe my thesis i s finished! It makes me very proud to think back four years, to when I

first started, and consider al l the things that I have accompl ished and my own personal

development during the course of my studies. This has definitely been one of the biggest and

hardest challenges I have ever taken on, and it never would have been accomplished without the

advice and support of the following people and organisations . It is my pleasure to acknowledge

these people.

Firstly, there are my supervisors Professor Errol Hewett and Dr Ian Ferguson for their patient

guidance and support throughout the course of my PhD. I recogni se and greatly appreciate all the

hours of time they have invested in me over the last four years, despite having hectic schedules of

their own.

I would also l ike to say a special thanks to Drs Sandy Lang and E lspeth MacRae, who 'got the ball

rol l ing' for me, and to Or Mike Clearwater for the considerable quantity of information, expertise

and feedback that he has provided me with over the l ast four years. Or Nihal Oe Si lva also

deserves a special mention for the statistical advice he has shared with me. In addition the

following people have all provided help and/or advice: Annette R ichardson, Or Jeremy Burdon,

Linda Boyd, Or Cristos Xiloyannis, Dr Mike Currie, Dr Bartelo Dichio, Or Ian Hal let, Or Nagin

Lal lu, Dr Kate Maguire, Dr Ken Marsh, Dr Oenny Meyer, Al istair Mowat, Steven Owen, Or

Kevin Patterson, Paul Sutherland, Dr Grant Thorp, Or Jens Wtinsche and the orchard management

team at Te Puke HortResearch .

Also I would l ike to thank the people I worked with a t Apata Centrepac Ltd and Satara Co­

operative Group Ltd, for assisting with the grading, packing and storage of fruit from my

experiments; Oave Jury and staff at Mul ler and Associates who worked with me on the experiment

reported in Chapter three; Growers B ruce Vanstone, Tom Newman, Howard Strahan and Oave

Burnside who provided experimental vines.

HortResearch has provided the required facil i ties to complete my research and staff there, many of

whom are mentioned above, have been particularly great to me over the last four years, not just

providing technical assistance and advice, but often friendship as wel l . Generous financial

assistance from the Tertiary Education Commission (formerly from the Foundation for Research,

Science and Technology) and ZESPRJTM International Ltd has not only ensured that this research

even 'got off the ground' , but has enabled me to present papers at several international conferences

(Appendix 1 ) . ZESPRJTM International Ltd also provided me with opportunities to interact with

growers and other industry personnel .

Lastly, I would l ike to thank my boyfriend Neil , friends and family for getting me through the

tough t imes and for their support and understanding when I could not always be as social as I

would have l iked. Plenty of t ime to make up for that now!

v

CONTENTS

ABSTRACT

ACKNOWLEDGEMENTS

CONTENTS

LIST OF FIGURES

LIST OF TABLES

LIST OF ABBREVIATIONS

CHAPTER 1 . General Introduction

1 . 1 . Internal quality in kiwifruit : importance of high Ca and OM concentrations

1 .2 .

1 .3 .

l A.

1 .5 .

1 .6 .

1 . 1 . 1 . Fruit DMC and taste

1 . 1 .2. Postharvest quality and fruit mineral and DM concentrations

1 . 1 .3 . Factors affecting fruit variabil i ty

Carbohydrate, mineral nutrient and water accumulation in kiwifruit

1 .2. 1 . Fruit growth

1 .2.2. Phloem transport and carbohydrate accumulation

1 .2.3. Xylem transport, water and mineral accumulation

1 .2.4. Fruit DMC and its relationship to Ca

Canopy management and fruit quality

1 .3. 1 . Vine description

1 .3.2. Canopy management

Fruit water loss and kiwifruit internal quality

1 .4. 1 . Fruit skin structure and water loss

1 .4.2. Fruit surface area and water loss

Vascular tissues and their development in the fruit stalk

1 .5 . 1 . Effects of vascular capacity on carbohydrate and mineral accumulation

1 .5 .2. Xylem morphology

1 .5 .3. Hydraulic conductance

1 .5 .4. Phloem morphology

1 .5 .5 . Vascular development in the frui t stalk

1 .5 .6. Factors affect ing vascular development

Auxins and fruit quality

1 .6. 1 . Auxins and vascular differentiation

1 .6.2. Auxins and cell division and elongation

1 .6.3. Auxins and carbohydrate accumulation within the fruit

1 .6.4. Auxin application and the effect of seeds

1 .6 .5 . Effect of auxin transport inhibitors on mineral and carbohydrate accumulation

iii

V

vii

xiii

xix

xxii i

1

5

7

1 0

1 0

1 1

1 3

1 9

2 1

2 1

23

30

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35

35

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39

39

42

43

44

45

45

46

48

V1l

1 .7 . Problem Statement and Objectives

1 . 7 . 1 . Statement of the problem

1 . 7 .2 . Objectives

CHAPTER 2. General Methods

2. l .

2 .2 .

2.3 .

2.4.

2 .5 .

2.6.

2.7.

Chemicals

Fruit selection

Field preparation of fruit and fruit stalks for assessment

Secondary vascular measurements

Mineral analysis

Dry matter concentration

Xylem functionality

2 .7 . 1 .

2 .7.2 .

Dye infiltration

Determining xylem functional ity

2 .8 . Harvest dates

2.9. Fruit storage assessment

2. 1 0. Data handl ing and statistics

2 . 1 0. 1 . Data handling

2 . 1 0.2 . Experimental design and statistical analysis

CHAPTER 3. Kiwifruit Pruning Systems and Fruit Quality

3 . l .

3 .2 .

3 .3 .

3.4.

3 .5 .

vii i

Introduction

Materials and methods

3.2 . 1 Experimental design

3.2 .2 Pruning strategies

3.2 .3 . Seasonal analyses

3 .2 .4. Experimental problems

3 .2 .5 . S tatistical analysis

Results

3 .3 . 1 . Canopy attributes

3.3 .2 . Yield components

3 .3 .3 . Fruit data

3 .3.4. Storage and sensory data

Discussion

3.4. 1 .

3 .4.2.

Fruit quality: physical attributes

Fruit quality as perceived by the consumer

Conclusions

49

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60

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60

63

63

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72

72

72

73

74

80

83

83

87

89

CHAPTER 4. Crop Load Effects on Photosynthesis and Transpiration and

Subsequent Effects on Fruit Quality

4. 1 . Introduction

4.2. Materials and methods

4.2. 1 . 2002/2003 Season

4.2 .2 . 200312004 Season

4.2 .3 . Statistical analysi s

4.3 . Results

4.3 .1. Canopy density

4.3 .2 . Fruit and fruit stalk data

4.3 .3 . Photosynthesis and stomatal conductance

4.3.4. Storage trial results

4.4. Discussion

4.4. 1 . Crop load effects on photosynthesis and stomatal conductance

4.4.2. Crop load effects on fruit properties

4.4.3. Crop load effects on postharvest fruit quality

4.5 . Conclusions

CHAPTER 5: Carbohydrate and Mineral Accumulation in Long, Non­

Terminating and Short, Terminating Shoots: Effects of Girdling

and Defoliation

5 . 1 . Introduction

5 .2 . Materials and methods

5 .2 . 1 . Experimental design and treatments

5 .2 .2 . Harvest procedure

5 .2 .3 . Xylem functionality

5 .2 .4 . Statistical analysis

5 .3 . Results

5 .3. 1 . December harvest results

5 .3 .2 . January harvest results

5 .3 .3 . April harvest results

5 .4 . Discussion

5.4. 1 . M inerals

5.4.2. Fruit weight and dry matter concentration

5 .5 . Conclusions

91 9 1

93

93

95

96

96

96

98

lIO

1 1 4

1 1 7

1 1 7

1 2 1

1 24

1 25

127

1 27

1 29

1 29

1 30

1 30

1 3 1

1 3 1

1 3 1

1 33

1 35

1 37

1 37

1 42

1 44

IX

CHAPTER 6: Fruit Transpiration, Skin Permeance, Minerals and Carbohydrate

Accumulation

6. l .

6 .2 .

6.3.

6.4.

6.5.

Introduction

Materials and methods

6.2. 1 . The effect of fruit transpiration on mineral and carbohydrate accumulation in

frui t from long , non-terminating and short, termi nating shoots

6.2.2. Effect of shoot type on fruit permeance

Results

6.3. 1 . The effect of fruit transpiration on mineral and carbohydrate accumulation in

fru it from long, non-terminating and short, terminating shoots

6.3.2. Effect of shoot type on fruit permeance

Discussion

6.4. 1 .

6.4.2.

Mineral accumulation and fru i t transpiration

Shoot type effects

6.4.3 . Mineral accumulation and fruit permeance

Conclusions

CHAPTER 7: Seasonal Trends in Vascular Development of Fruit Stalks From

Long, Non-Terminating and Short, Terminating Shoots

7. 1 .

7.2.

7 .3 .

7.4.

Introduction

Materials and methods

7.2. 1 . Experimental design

7.2 .2 . Statistical analysis

Results and discussion

7.3. 1 . Flower and fruit stalk growth

7 .3 .2 . Vascular development in the fruit stal k

7 .3 .3 . Spatial distrihution of phloem and xylem tissues within the fruit stalk

Conclusions

CHAPTER 8: TIBA and Fruit Seed Number Influences Mineral and

Carbohydrate Accumulation in Kiwifruit: A Potential Role for

Auxins

8. l .

8 .2 .

8 .3 .

x

Introduction

Materials and methods

8.2. 1 . TIBA and frui t qual ity

8.2.2. TIBA plus girdling or defoliation and fruit quality

8.2 .3 . Seeds and frui t qual ity

Results

147

1 47

1 49

1 49

1 5 1

1 56

1 56

1 60

1 63

1 63

1 65

1 68

1 68

171

1 71

1 72

1 72

1 72

1 73

1 73

1 74

1 79

1 8 1

185

1 85

1 89

1 89

1 9 1

1 93

1 96

8.4.

8 .5 .

8.3. 1 .

8 .3 .2 .

8 .3 .3.

TIBA and frui t qual i ty

Effects of TIBA plus girdl ing or defoliation on fruit quality

Seeds and fruit qual ity

Discussion

8 .4. 1 .

8 .4.2.

8 .4.3.

8.4.4.

Mineral ion accumulation

Fresh and dry weight accumulation

Girdling and defol iation in relation to TIBA effects on fruit quality

TIBA and fruit qual i ty in storage

Conclusions

CHAPTER 9: Non-destructive Measurement of Mineral Concentrations in Xylem

Sap of Different Kiwifruit Shoot Types Using Spittlebugs

9. 1 .

9 .2 .

9.3 .

9.4.

9.5.

Introduction

Materials and methods

9.2 . 1 .

9 .2 .2 .

9.2.3 .

9.2.4.

9 .2 .5 .

9 .2 .6.

9 .2 .7 .

9 .2 .8 .

Results

9.3 . 1 .

9 .3 .2 .

9 .3 .3 .

9 .3 .4.

9.3.5.

Plant material

Bug collection and xylem sap feeding

Collection of excreta sap

Excreta sap analysis

Spittlebug excreta sap and xylem sap composition

Vacuum-extraction of xylem sap

Axi llary shoot attributes

Statistical analysis

Bug feeding patterns

Excreta sap ion composition

The effect of axi l lary shoot-type on xylem sap composition

Ion concentrations gradients down a cane

Calibration solution results

Discussion

9.4. 1 .

9.4.2.

Xylem sap mineral composition

Insect feeding patterns

9.4 .3 . Spatial variation in xylem sap mineral ion concentrations: evidence that

minerals are partit ioned on a demand basi s

Conclusions

CHAPTER 10: General Discussion

1 0. 1 . Thesis objective

1 0.2 . Factors affecting Ca and carbohydrate accumulation in kiwi fruit

1 0.3 . Factors affecting fruit DM, Mg, K and P concentrations

1 96

208

2 1 7

22 1

2 21

224

227

227

228

231

23 1

232

232

233

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235

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240

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249

249

250

257

XI

1 0.4. Potential to manipulate fruit DM and Ca concentrations to benefit fruit quality 258

1 0.5 . Directions for future research 26 ]

1 0.6. Conclusions 263

REFERENCES

APPENDIX I. International Conference and Industry Presentations

APPENDIX 11. Chemicals Utilised in Fruit Assessment

XII

265

287

288

List of Figures

Chapter 1 :

1 . 1 . Average DMC of fruit from 24 different orchards within New Zealand, as

measured in 2004 and 2005.

1 .2 . Fresh and dry weight accumulation i n 'Hayward' kiwifruit .

1 .3 . Starch and soluble sugar accumulation in ' Hayward' kiwifruit .

l A. Soluble sugar accumulation in 'Hayward' fruit .

1 .5 . Mineral accumulation in different organs within kiwifruit vines.

1 .6 . Fruit Ca contents and concentrations in 'Hayward' kiwifrui t

1 .7 . Fruit P, Mg and K contents and concentrations i n 'Hayward' kiwifrui t .

1 .8 . Seasonal changes in DMC in ' Hayward' kiwifruit .

1 .9 . Kiwifruit vine trained on pergola trel l i s .

1 . 1 0. A kiwifruit stalk and cross-section of the stalk of a mature fruit.

Chapter 2:

2. 1 .

2 .2 .

Wind tunnel design for measuring xylem functional ity.

A transverse kiwifruit section i l lustrating the stained and unstained ventromedian

carpel lary (VMC) bundles .

Chapter 3:

3 . 1 .

3 .2 .

Design of the pruning systems experiment .

A digi tal hemispherical photo taken from underneath the canopy of a k iwifruit

vme .

3 . 3 . Flowering and yield in monitored leader and conventionally pruned (LP and CP)

3 04.

3 .5 .

3 .6.

3 .7 .

vines, as measured over three seasons.

Yield per area in LP and CP vines.

DMC of fruit from LP and CP vines, as measured over three seasons.

Relationship between crop load and fruit DMC with canopy openness and LAI

values i l lustrated.

Relationship between crop load and frui t DW per m2•

3 .8 . Fruit Ca, Mg, K and P concentrations i n LP and CP vines, as measured over three

seasons.

7

J O

1 2

1 2

1 6

1 7

1 8

20

2 1

40

57

58

65

70

74

75

76

77

78

79

X\lI

Chapter 4:

4. 1 .

4 .2 .

Canopy l ight transmission in high and low crop load, pruned and unpruned vines.

Canopy openness and LAI, as measured at three different crop loads .

4 .3 . Canopy openness and LAI in high and low crop load, pruned and unpruned

VInes.

4.4. Fresh weight and DMC of fruit harvested from pruned and unpruned long, non­

termjnating ( long) and short, terminating ( short) shoots.

4 .5 .

4 .6 .

Fresh weight and DMC of fruit from long and short shoots, as measured at three

different crop loads.

Relationship between crop load and fruit dry weight.

4 .7 . Potassium, P, Ca and Mg concentrations in fruit from high and low crop load,

pruned and unpruned vines.

4 .8 . Potassium, P, Ca and Mg concentrations in fruit harvested from pruned and

unpruned long and short shoots from high and low crop load vines .

4 .9 . Xylem and phloem area and estimated secondary xylem conductance i n the stalks

of fruit from high and low crop load pruned and unpruned vines.

4. 1 0. Phloem and xylem area in stalks of fruit from pruned and unpruned long and

short shoots .

4 . 1 1 . Estimated secondary xylem conductance in talks of fruit from pruned and

97

97

98

99

1 00

1 0 1

1 02

1 03

1 05

1 06

unpruned long and short shoots. 1 07

4. 1 2 . Relationship between fruit fresh weight, dry weight, DMC and fruit stalk phloem

and xylem area. 1 08

4 . 1 3 . Relationship between fruit Ca, Mg, K and P and fruit stalk xylem area. 1 09

4 . 1 4. Relationship between estimated fruit stalk secondary xylem conductance and

fruit Ca concentration. 1 09

4 . 1 5 . Relationship between leaf stomatal conductance and net assimi lation rate. 1 1 0

4 . 1 6. Photosynthesis and stomatal conductance in leaves from high crop load, pruned

and unpruned vines and low crop load, pruned and unpruned vines.

4. 1 7 . Photosynthesis and stomatal conductance in leaves from long, pruned and

unpruned shoots and short pruned and unpruned shoots.

4 . 1 8 . Relationship between leaf photosynthetic rates, canopy openness and LAI.

4 . 1 9. Relationship between leaf stomatal conductance and fruit Ca, Mg, K and P

concentrations.

4 .20. Relationship between leaf photosynthetic rates and fruit DMC in short and long

shoots.

xiv

1 1 1

1 1 2

1 1 3

1 1 4

1 1 5

4.2 1 . Fruit firmness and ripe soluble sol ids concentration in high and low crop load,

pruned and unpruned vines after 24 weeks at I -3°C. 1 1 6

4 .22 . Relationship between LTB incidence and blemish incidence . 1 1 6

Chapter 5:

5 . 1 . Xylem functional ity of VMC bundles in kiwifruit fol lowing spring defol iation of

long and short shoots, as measured on 2 1 December 200 I .

5 .2 . Xylem functional ity of VMC bundles in kiwifruit fol lowing spring and summer

defol iation of long and short shoots, as measured on 20 January 2002.

5 .3 . Xylem functional ity of VMC bundles in kiwifruit fol lowing spring and ummer

defoliation of long and short shoots, as measured on 27 Apri l 2002.

Chapter 6 :

6. 1 .

6 .2 .

6 .3 .

6.4.

6 .5 .

Fan treatment design .

Relationship between fruit weight and surface area.

Seasonal changes in permeance and surface area of fruit from long and short

shoots.

Relationship between permeance and surface area of fruit from long and short

shoots .

Trichome density in "Hayward' kiwifruit .

Chapter 7:

7. 1 . Flower and fruit stalk length and diameter development in sta lks from long and

short shoots.

7 .2 .

7 .3 .

7 .4.

Cross-sections of kiwifruit pedicels two and twenty-one weeks after anthesis .

Secondary phloem, xylem and pith development in flower and fruit stalks from

long and short shoots.

Seasonal changes in secondary xylem vessel number and estimated conductance

in stalks from flowers and fruit on long and short shoots.

7 .5 . Relationship between flower and fruit stalk diameter, phloem and xylem areas

7.6.

7 .7 .

and estimated secondary xylem conductance.

Spatial distribution in pith, xylem and phloem areas down a fruit stalk .

Spatial distribution in xylem vessel number and estimated conductance down a

fruit stalk.

1 33

1 34

1 36

1 50

1 54

1 6 1

1 62

1 62

1 73

1 74

1 75

1 76

1 78

1 79

1 80

xv

Chapter 8:

8. 1 .

8.2.

8.3.

8 .4.

Diagrammatic representation of one vine repl icate.

Relationship between actual and estimated fruit seed numbers and, between the

pol len solution concentration and estimated fruit seed numbers.

Vascular discolouration in TIDA-treated fruit.

Fruit fresh weight, DM and Ca concentrations, as mea ured on 7 January 2003

and 5 May 2003, fol lowing TIDA appl ication.

8 .5 . Xylem and phloem area, xylem vessel number and estimated conductance, as

measured on 10 January 2003, fol lowing TIDA application.

8.6. Fruit Ca, Mg, K and P concentrations, as measured on 1 0 January 2003,

following TIDA application.

8.7. Xylem and phloem area, xylem vessel number and estimated conductance, as

measured on 2 1 Apri l 2003, fol lowing TIDA application.

8 .8 . Fresh weight and DMC, as measured on 21 April 2003, following TIDA

8.9.

application .

Fruit Ca, Mg, K and P concentrations, as measured on 2 1 April 2003, following

TIDA application.

8. 1 0. Functional ity of the xylem vessels in the VMC bundles, as measured on 1 0- 1 1

January 2003, fol lowing TIDA appl ication.

8 . I I . Rel ationship between xylem and phloem area and fruit FW.

8. I 2 . Relationship between estimated secondary xylem conductance and fruit Ca, Mg,

1 92

1 95

1 96

200

20 1

202

203

204

205

206

206

K and P concentrations. 207

8. 1 3 . Calcium concentrations in TIDA-treated fruit from short control, defoliated and

gird led shoots. 2 I 1

8 . 1 4. DMC in TIDA-treated fruit from long control, defoliated and girdled shoots. 2 1 4

8. 1 5 . Relationship between estimated fruit seed number, FW, DW and fruit DMC. 2 1 7

8 . I 6. Relationship between estimated fruit seed number and fruit Ca, Mg, K and P

concentrations.

8 . I 7. Relationship between estimated fruit seed number, phloem and xylem areas, and

the phloem: xylem ratio.

8 . I 8. Relationship between the estimated fruit seed number and secondary xylem

vessel number and estimated conductance.

8 . I 9. Percentage of sma l l , medium and l arge diameter vessels contributing to the

estimated secondary xylem conductance in fruit with different seed numbers.

8.20. Concentrations of Ca, Mg, K and P in relation to estimated secondary xylem

conductance in fruit stalks.

XVI

2 1 8

2 1 9

2 1 9

220

220

8.21. Diagrammatic representation of the proposed effects of TmA on Ca and DM

concentrations in kiwifruit.

8 .22. Proposed rate of DW increase in fruit with low and h igh cel l numbers.

Chapter 9:

9 . 1 . Cages used to contain the spittlebugs whilst feeding on kiwifruit fruit stalks and

leaves .

9 .2 .

9.3.

9.4.

9.5 .

9 .6 .

Rate of excreta sap production throughout the day.

Seasonal changes in the volume of excreta sap produced per insect per day.

Relationship between Ca, Mg and K concentrations in the xylem sap.

Seasonal changes in excreta sap mineral ion concentrations .

Mean ratio of excreta sap ion concentrations verses that in the corresponding

cal ibration solution.

Chapter 10:

10.1. Diagrammatic representation of the factors that may affect carbohydrate, mineral

and water accumulation in 'Hayward ' kiwifruit.

222

225

233

237

238

239

240

242

251

XV I I

List of Tables

Chapter 1:

1 . 1 . Concentration of soluble and insoluble carbohydrates in kiwifruit .

1 .2 . Incidence of storage disorders in 'Hayward' kiwifrui t from s ix different growi ng

regions after 24 weeks storage at O°C.

1 .3 . Average fruit mineral and DM concentrations in 'Hayward' kiwifruit from s ix

different growing regions after 24 weeks storage at O°c.

1 .4.

1 .5 .

1 .6.

Vine characteristics affected by different orchard management strategies.

Cell types of the secondary xylem of kiwifrui t .

Cel l types of the secondary phloem of kiwifruit .

Chapter 3:

3 . 1 .

3 .2 .

3 .3 .

3 .4.

3 .5 .

Canopy l ight transmi ssion in the leader and fruiting zones of leader and

conventionally pruned (LP and CP) vines.

Canopy openness and leaf area index in LP and CP vines.

Fresh weight of fruit from the leader and fruit ing zones of LP and CP vines.

DMC in fruit from the leader and fruiting zones of LP and CP vines.

Ripe soluble solids content of fruit from the leader and fruiting zones of LP and

CP vines.

3 .6. Firmness of fruit from three different count sizes, from LP and CP vines after 26

3 .7 .

3 .8 .

weeks in storage at O°c.

Storage disorder incidence in fruit from three different count sizes from LP and

CP vines.

Attributes of LP and CP vines.

Chapter 4:

4 . 1 . Attributes of leaves, fruit stalks and fruit on long, non-terminating (long) and

short terminating (short) shoots.

3

5

8

9

37

39

7 3

7 3

7 5

76

8 1

82

83

85

1 0 1

XIX

Chapter 5:

5 . 1 . Several quality attributes of fruit from long and short axi l lary kiwifruit shoots, as

measured on 1 9 December 200 I , fol lowing shoot defol iation or girdl ing on 24

November 200 1 .

5 .2 . Several quality attributes of fruit from long and short axi l l ary kiwifruit shoots, as

measured on 25 January 2002, fol lowing shoot defol iation on 24 November 200 I

and 5 January 2002, or shoot girdl ing on 24 November 2002.

5 .3 . Several qual ity attributes of fruit from long and short axi l lary kiwifruit shoots, as

measured on 25 Apri l 2002, fol lowing shoot defol iation on 24 November 200 1

and 5 January 2002, or shoot girdl ing on 24 November 2002 and 1 February

2002.

Chapter 6:

6. 1 . Attributes of kiwifruit from long and short axi l lary shoots harvested 46 days after

ful l bloom (DAFB) fol lowing the appl ication of control, fan and bag treatments

at petal fal l .

6.2. Attributes of fruit stalks from fruit on long and short axi l lary shoots harvested 46

6.3.

DAFB fol lowing the application of control , fan and bag treatments at petal fal l .

Attributes of kiwifruit from long and short axi l lary shoots harvested 1 44 DAFB

fol lowing the appl ication of control , fan and bag treatments at petal fal l .

6.4. Attributes of fruit stalks from fruit on long and short axi l l ary shoots harvested

1 44 DAFB fol lowing the application of control, fan and bag treatments at petal

1 32

1 34

1 35

1 57

1 58

1 59

fal l . 1 60

Chapter 7:

7. 1 . Percentage of small , medium and l arge secondary xylem vessel s and their

contribution to the total estimated secondary xylem conductance in fruit stalks

from long and short shoots.

Chapter 8:

8 . 1 .

xx

Several fruit qual ity attributes, measured on 7 January 2003, fol lowing

appl ication of TIBA, at 50 and 1 00 mg L- 1 on 5 December 2002, 8 DAFB .

1 77

1 98

8.2 . Several fruit quality attributes, measured on 5 May 2003, fol lowing application

of TmA, at 50 and lOO mg L-1 on 5 December 2002, 8 DAFB .

8 .3 . Several fruit quality attributes, measured on 14 January 2003, following TmA

application to fruit on girdled, defoliated or control (untreated) long and short

axi l lary shoots.

8 .4. Several fruit quality attributes, measured on 30 April 2003, fol lowing TmA

application to fruit on girdled, defoliated or control long and short axil l ary

shoots.

8 .5 . Xylem functionality and corresponding frui t fresh weights in untreated and

TmA-treated fruit from long and short control , defoliated or girdled shoots.

8 .6. Postharvest attributes of untreated and TmA-treated fruit from long and short

control , defoliated and girdled axil lary shoots, as measured after 24 weeks in

storage at O°e.

Chapter 9:

9. 1 .

9 .2 .

Attributes of long and short axi l l ary shoots .

Mineral concentration gradient in sap down a cane.

Chapter 10:

1 0. 1 . Evidence that auxin may indirectly affect carbohydrate and Ca accumulation in

kiwi fruit by regulating vascular differentiation in f1ower/ fruit stalks and/or fruit

cell division.

1 99

209

2 1 2

2 1 5

2 1 6

24 1

242

254

XXI

List of Abbreviations

ABA

ANOVA

AuG

BER

CME

CP

CPPU

CSA

DAFB

DM

DMC

DPFB

DW

FB

FW FZ

GLA

GLM

Gs

HP

HUP

IAA

Kh LAI

L:F

LP

LSD

LTB

LUP

LwP

LZ

NAA

NPA

NPQ

absci sic acid

analysis of variance

autumn girdling

water activity

blossom end rot

chloroflurenolmethylester

conventional ly-pruned

N 1 -(2-chloro-4-pyridyl )-N3-phenylurea

cross-sectional area

days after ful l bloom

dry matter

dry matter concentration

days prior to ful l bloom

dry weight

fu l l bloom

fresh weight

fruiting zone

gap l ight analyser

general l inear model

stomatal conductance

high crop load, pruned (vines)

high crop load, unpruned (vines)

indole-3-acetic acid

hydraul ic conductivity

leaf area index

leaf: fruit (ratio)

leader-pruned

least significant difference

low temperature breakdown

low crop load, unpruned (vines)

low crop load, pruned (vines)

leader zone

napthalene acetic acid

I -N-napthylphthalamic acid

non-photochemical quenching

XXIII

PAR

PC

PGR

PIX

Pn

RH

rSSC

SA

SB

SE

SLW

SmD

SpD

SpG

SSC

TlBA

VMC

VPD

WAFB

XXIV

photosynthetically active radiat ion

personal computer

plant growth regulator

1 , I -dimethyl-piperidinium

Net photosynthesis

relative humidity

ripe soluble solids concentration

surface area

short-base (proximal cane end)

short-end (distal cane end)

specific leaf weight

summer defoliation

spring defol iation

spring gird l ing

soluble solids content

2,3,S-tri iodobenzoic acid

ventromedian carpellary (vascular bundle)

vapour pressure deficit

weeks after full bloom