The effects of training systems and crop load on stored starch in young stone fruit trees

The effects of training system and crop load on stored starch as part of non-structural carbohydrates (NSCs) in stone fruit trees is important for understanding their carbohydrate economy. NSCs are important energy storage compounds in plants during flowering and fruit set and when carbon assimilation is reduced due to biotic and abiotic stress such as low nutrient and water supply. There is limited knowledge on the effects of crop load on starch accumulation in peach and nectarine as influenced by training system. Our field experiment aimed to understand starch content in wood of young stone fruit trees as affected by training system and crop load. Starch content was measured in wood sampled from 3-year-old peach and nectarine trees that were trained to a Tatura trellis or as double vertical axis with two main branches during spring (after shuck fall), summer and winter. Starch concentration was obtained by enzymatic digestion of powdered wood and subsequent colorimetric quantification. Results indicate that trees trained to Tatura trellis had higher stored starch concentration than double vertical axis trees. 'August Flame' peach had less fluctuation during the year than 'Autumn Bright' nectarine.