[Chardonnay Fruitfulness As Influenced By Vine Carbohydrate Partitioning]

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Abstract

Effects of pruning on yield, three basic measures of fruit composition and cane carbohydrate concentration in Vitis Vinifera cv. Pinot Noir vines were investigated in a cool climate wine area of Tasmania (Australia) from 2008 to 2010. Four pruning treatments comprising of 10, 20, 30, and 40 nodes per vine were imposed on 8-year-old vines. Bunch number, bunch weight, berry number, and berry weight were measured. Cane samples were collected in the second year for tissue carbohydrate analysis. Fruit was analysed for pH, skin colour and sugar level. For each of the yield components measured there was a significant year effect but no interaction between year and pruning treatment. In each of the three years pruning to a higher bud number decreased the number of bunches per bud but no other yield component. Pruning treatment significantly affected starch content of the winter canes but not soluble carbohydrate levels. Pruning affected both pH and colour of fruit but not sugar concentration.

Table of Contents

ACKNOWLEDGEMENT2

DECLARATION3

ABSTRACT4

LIST OF FIGURES7

INTRODUCTION8

Layers of cells9

Endodermis9

Cuticle / waxy10

Bunch size10

e- Berry size11

Chemical characteristics of Grape11

PLANT SELECTION AND PLANTING18

Pruning19

Fertilization20

Weed Control20

Harvest21

Tasmanian wine regions21

The Annual growth cycle in grapevines24

Bud break25

FIG 1: BUD BREAK25

Flowering25

FIG 2: FLOWERING26

Fruit set26

FIG 3: FRUIT SET27

Veraison (Colouring)27

FIG 4: VERAISON28

Harvesting28

FIG 5: HARVESTING28

Managing Grapevine Growth A-Training and Trellising28

Four-arm Kniffin30

High-wire cordon system30

Temperture Response30

a-Temperture effect on flowering30

b- Temperture on fruit set31

Yield Prediction31

Climate Change32

Pruning33

Canopy Management and Fruit Thinning33

Carbohydrate storage39

REFERENCES41

List of figures

FIG 1: Bud Break20

FIG 2: Flowering21

FIG 3: Fruit Set22

FIG 4: Veraison23

FIG 5: Harvesting24

Chardonnay Fruitfulness As Influenced by Vine Carbohydrate Partitioning

Introduction

The yield of vines is dependent, in part, on the number of buds left on the vine at pruning. After budburst, bunch number on the developing shoots determines potential crop, and leaf area determines how much crop can be ripened. Lighter pruning, in general, increases yield but it may also be associated with negative effects on fruit quality such as lower total soluble solids and modified pH and intractable acidity (Archer, 1989, 74-77). Higher bud numbers left at pruning do not always give a linear yield response, and the vine tends to compensate by reducing the number of buds producing shoots, the number of bunches per shoot and average bunch weight.

Not all reports indicate higher yields following lighter pruning, and similarly, some high-yielding cultivars have been reported to compensate for heavy pruning by increasing the numbers of fruitful basal buds that burst. From the considerable literature on pruning levels and yield in other cultivars, it is clear that different cultivars respond differently to different levels of pruning, within the same vine management ...