Monitoring multiyear individual tree flowering and yield reveals high variation among ‘Pinkerton’ avocado trees

Abstract

Most avocado cv. Pinkerton scions in Israel are grafted on seedling rootstocks, resulting in unstable yields. The objective of this study was to evaluate tree multiyear yield variation among ‘Pinkerton’ trees. We evaluated the flowering and yield variations among trees in two commercial avocado orchards, in Kibbutz Dan and Kibbutz Kfar-HaNassi, for 4 years. The multiyear average yield of the individual trees ranged from 9.5 to 73.7 kg tree−1 in Dan, and 1.7 to 53.8 kg tree−1 in Kfar-HaNassi, with coefficient of variation (CV) of 42% and 54%, respectively. Multiyear flowering intensity ranged from 2.7 to 4.9 and 2.41 to 5 (out of 5), with generally lower CV values of 14% and 26%, respectively. Multiyear alternate bearing index (ABI) ranged from 0.24 to 0.85 and 0.2 to 1, with CV of 25% and 32%, respectively. In Dan, the yield was negatively correlated with ABI. In Kfar-HaNassi, the yield was positively correlated with flowering intensity and negatively correlated with ABI. These results show that it may be important to monitor long-term individual tree yield, because removing low-yielding trees and selecting genetic material characterised by high yield and low ABI may be advantageous for establishing orchards with stable high yields.