To target high quality fruit, strategic cropload management practices are currently being investigated in designed field experiments at Agriculture Victoria, Tatura, in the stonefruit experimental field laboratory.

Manipulating fruit number per tree offers the ability to regulate available carbohydrates (assimilates), to maximize fruit size and fruit quality.

Cropload fruiting level treatment treatments being investigated are, high, medium and low cropload targets:

  • high treatment is minimally thinned fruit to levels to maximize competition between the fruit and available assimilate.
  • medium fruiting level is a moderately thin fruit to minimize competition between fruit and available assimilate, and
  • low thinning level treatment is heavily thinned fruit to eliminate competition between fruit and available assimilate.
2015/16 Investigations in the Stonefruit Field Laboratory for Experiments 3 - 10

Introduction

Introduction - Peach cv. August Flame on Vertical Leader tree training

Experiment 3

Introduction: Peach cv. August Flame on Tatura trellis tree training

Experiment 4

Introduction: Nectarine cv. Autumn Bright on Tatura Trellis tree training

Experiment 5

Introduction: Nectarine cv. Autumn Bright on Vertical Leader tree training

Experiment 6

Introduction: Apricot cv. Golden May on Vase and Tatura trellis tree training

Experiments 7 & 8

Introduction: Plum cv. Angeleno May on Vase and Tatura trellis tree training

Experiment 9 & 10

Table 1 Canopy crop-load experiments

Exp.FruitRoostockTreatmentTrainingDensityDate
planted
3Peach cv. August FlameNemaguardCrop Load (high, medium, low)Vertical Leader2222 trees/ha2013
4Peach cv. August FlameNemaguardCrop Load (high, medium, low)Tatura Trellis2222 trees/ha2013
5Nectarine cv. Autumn BrightNemaguardCrop Load (high, medium, low)Tatura Trellis2222 trees/ha2013
6Nectarine cv. Autumn BrightNemaguardCrop Load (high, medium, low)Vertical Leader2222 trees/ha2013
7Apricot cv. Golden MayMyrobalan H29CCrop Load (high, medium, low)Tatura Trellis2222 trees/ha2014
8Apricot cv. Golden MayMyrobalan H29CCrop Load (high, medium, low)Vase2222 trees/ha2014
9Plum cv. AngelenoMyrobalan H29CCrop Load (high, medium, low)Tatura Trellis2222 trees/ha2014
10Plum cv. AngelenoMyrobalan H29CCrop Load (high, medium, low)Vase2222 trees/ha2014

Results and Observations

Experiments 3 - 6 effects of low, medium & high crop load treatments on Fruit Weight and Brix

2017 Crop Load Management Results

Video discussion Dr Mark O'Connell discusses the results from the crop load management experiments (7min, 18 sec)

Time series videos

Every few weeks photos were taken of each experiment, and produced into a video to show the resulting growth of tree canopies and fruit development.

Time series videos experiments 3 to 8

Crop load and fruit position influence variability in nectarine quality

Crop load and fruit position

This study looks at the influence of crop load and fruit position on size and soluble solids concentration.

The effects of canopy architecture and crop load on non-structural carbohydrate in young stone fruit trees

Understanding the effects of canopy architecture and crop load on non-structural carbohydrate (NSC) in stonefruit trees is fundamental to boost early bearing and ensure consistent fruit size and quality.