Pollen load affects fruit set, size, and shape in cherimoya

Cherimoya (Annona cherimola Mill.) is a subtropical fruit crop that exhibits protogyny dichogamy and for which the original pollinators are not present in the main producing countries. Under such circumstances the achievement of profitable yields depends on hand pollination. The present work explores the effects of the amount of pollen applied on pollen–pistil interaction and on fruit set, size, shape and growth. Pollen dilution with Lycopodium spores reduced fruit set and size and favoured the appearance of misshapen fruits, whereas the application of double amount of pollen did not improve fruit size and increased fruit set only the first year. Pollen load did not affect fruit growth model, which always followed a double sigmoid pattern. Nevertheless, the slopes of the curves during the two rapid growth phases were higher when a larger amount of pollen grains was applied. Seed index (seed number per 100 g of fresh fruit weight) rose slightly as pollination level increased.