Current situation and challenges of cultivating banana and other tropical fruits in the subtropics

The production of bananas and other tropical fruit crops in the subtropics is highly influenced by climate. In the case of bananas, climate causes undesirable physiological phenomena and long cropping cycles, despite which yields obtained in the subtropics can be excellent. True tropical fruits like rambutan, mangosteen or durian, highly demanding both in temperature and humidity requirements, cannot be economically cultivated in the subtropics, but others like mango, litchi or avocado, have become important commercial crops in many subtropical countries through many years of research and grower efforts. Many other tropical fruits may perform well in the subtropics, but considerable research and development must still be conducted before they can become important commercial crops. Management of pests is generally easier and cheaper compared with the tropics due to the constraints of low temperatures and humidity on pathogen activity. This has important relevance for organic cultivation, which can add value to the production of tropical fruits in the subtropics. Since tropical trees produce fewer annual flushes per year in subtropical climates, tree growth control is easier and suitable pruning techniques allow their cultivation at high density, facilitating high initial yields with optimal management. Proximity to the market is an additional advantage, not only for cost reasons, but also due to a reduced carbon footprint. Special problems and challenges for tropical fruit cultivation in the subtropics include the growing importance of Fusarium wilt and weevil borer on banana in cooler climates, and the impact of low temperatures in relation to flowering, pollination, fruit set, fruit quality and yield in many tropical tree crops. The actual importance of and future prospects for, developing banana and other relevant tropical fruits in the subtropics, is analysed in this paper