Cultural practices to overcome dormancy in temperate fruit trees in tropical and subtropical zones

摘要

The cultivation of temperate fruit trees in tropical and subtropical zones has to tackle several problems, mainly related to the endo-dormancy of the buds. One way is by utilizing suitable cultivars with low winter-chilling requirements. In some casesthere is a tendency in existing early-ripening cultivars to have low chilling requirements, but their quality is poor. During the last few years, breeders have combined the low chilling requirement, early-flowering and earliness with an improvement in quality. In some species the selection of suitable rootstocks has reduced the chilling requirement of the scion by decreasing its vigour. However, in many tropical and subtropical zones the application of some cultural practices is necessary to improve the production and the quality. The practices aim to induce leaf-fall, early dormancy and reduce the vigour of the shoots. Cultural practices such as withholding irrigation water, defoliation, use of certain methods of pruning and growing the trees with training forms have shown good results. The application of cultural practices can be a valuable strategy both to improve the production of the temperate fruits in tropical and subtropical zones and to reduce possible damage to the environment by spraying chemicals in order to break dormancy.