FLOWERING PATTERN AND FRUITFUL CAPACITY OF 'FINO DE JETE' CHERIMOYA SHOOTS

Abstract

Cherimoya is a subtropical fruit tree indigenous to the inter-Andean valleys between Peru and Ecuador. Cherimoya dichogamy and the lack of efficient pollinators in Spain hinder natural fruit set, making hand pollination unavoidable. Cherimoya flowers are formed on current season growth and on 1-year-old shoots of different vigour. Hand-pollination allows selection of the more convenient flowers to be pollinated in order to obtain high quality fruits. Here, we have determined the frequency, fertility and flowering dates and patterns of the different kinds of shoots (high, medium and low vigour) found in cherimoya trees as the first step to modifying current pruning procedures. The results show that adult vase-trained trees traditionally-pruned have an equilibrated proportion of vigorous, semi-vigorous, and weak shoots. However, the number of flowers formed and the distribution of flowers along the wood were significantly different among the different kinds of shoots. Vigorous shoots formed an average of 65 flowers; semi-vigorous shoots produced an average of 36 flowers, while weak wood formed only 17 flowers per shoot. Flowering pattern was also different. Basal nodes of vigorous shoots formed a high proportion of flowers, while apical nodes did so in weak shoots. The flowering season extended from May to August with peak flowering occurring in mid-June with no differences in flowering dates among shoots. Based on these results, we recommend pruning to focus on encouraging the production of vigorous and semi-vigorous shoots able to sustain a crop load of 400 fruits per tree and to develop sufficient pollen-donor flowers. Hand-pollination is advised for flowers formed in the basal-central nodes of these shoots. A higher number of flowers per node did not diminish their size.