The effect of a water deficit on fruit tree phenology, fruit production, fruit quality and storability of various apple cultivars

This study aimed to investigate the outcomes of before and after-harvest water deficits on apple production in a pre- and postharvest context. More specifically, the impact of water stress on bud break, flower quality, yield and postharvest storability. Cultivars which exhibited water stress related disorders during the recent drought were selected.

Fuji’, ‘Cripps Pink’ and ‘Golden Delicious’ trees were exposed to before and after-harvest water stress conditions to evaluate the effects of such conditions on phenology and fruit storability. After-harvest stress was implemented by covering treatment plots with sails and removing irrigation. Before-harvest water stress was implemented by reducing the amount of water to trees in replicate plots to 40% of the normal rate.

Deficit irrigation during the growing season resulted in smaller and firmer fruit with higher TSS levels at harvest and after storage. Removing irrigation after harvest did not significantly impact fruit quality at harvest and after storage in the following season.

Creating a water deficit did not influence budbreak progression. No clear trend was noted regarding flower quality. However, two of the four orchards that received before harvest deficit irrigation, exhibited significantly more flowers per cluster for the stressed trees compared to the unstressed trees. Before harvest water deficit irrigation had a significant impact on fruit maturity and post storage quality by firmer and smaller fruit with higher TSS levels.  The same was not necessarily noted in the after-harvest water stress treatments.

Should water shortages or drought conditions occur, the impact of removing irrigation after harvest is less compared to deficit irrigation during the season. Fruit size were smaller in stressed trees and with the exception of IB in ‘Cripps Pink’, there were no other quality issues.