Influence of the Current State of Global Warming on Fruit Tree Growth in Japan

Abstract

To grasp the actual influence of global warming on fruit tree production in Japan, a questionnaire was sent to prefectural institutes for fruit tree research. All 47 prefectures responded. All prefectures replied that global warming had affected on at least one tree species. The impact had extended to almost all tree species. The tree species were classified in to two types by responses of fruit development to climate changes. One group was the earlier development type and the other was the prolonged development type. The former were tree species in which both flowering and maturation periods had accelerated; these included Japanese pears, peaches and Japanese apricots. The latter were tree species in which the flowering period had accelerated, while maturation period had not accelerated; this type included apples, Japanese persimmons, grapes and satsuma mandarins. Fruit qualities of the prolonged development type had clearly changed, for example coloring faintly, enlarging, reduction of acid, softening and spoiling rapidly. Freezing injury on evergreen fruit trees and figs had decreased, while it had increased on other fruit tree species. Late frost damage showed both increase and decrease by region.