Pollination, initial fruit set and fruit drop in apples: analysis using mathematical models

Abstract

SummaryThe pollination model takes account of the effective pollination period (EPP) of the flowers, ovule fertility, insect visiting rate and the probability that insects will be carrying compatible pollen. In the fruit drop model it is assumed that the probability that a fruitlet will drop increases as the number of fertilized ovules it contains decreases; there is also a term for stress. The results indicate that the best strategy for ensuring adequate pollination is that which leads to a high insect visiting rate (e.g. many hives in orchards). Increasing the probability that insects will be carrying compatible pollen also increases the likelihood of successful pollination, but this is a ‘limiting returns’ relationship. Variations in the EPP cause relatively small differences in pollination and fruit set. The models can be used to explore a number of facets of pollination and fruit drop in apples.