Climatic Constraints on Rice Production in Taiwan

Abstract

Two crops of rice can be cultured each year in Taiwan. The yield of the second rice crop is, on average, 25% lower than that of the first crop. Climatic constraints such as extreme temperatures, lower solar radiation, monsoons, and heavy rainfall, are the main factors causing the yield loss. Chilling injury at the seedling nursery stage and prolonged mei-yu at the reproductive stage frequently impair the growth and development of the first rice crop and hence influence yield performance. For the second rice crop, high temperatures during the early growth phase of the rice plants shortens the vegetative growth duration and consequently results in lower tiller numbers and biomass production. The occurrence of typhoons and the associated heavy rainfall can also cause significant damage to the crop. In addition, low temperature and low solar radiation after heading adversely affect the performance of seed-settling and 1, 000-grain weight, especially in the central and northern parts of Taiwan. For improvement, it is suggested new cultivars suitable for growth under the stress conditions be developed, and the cultural practices be improved to overcome the impacts caused by unfavorable climatic constraints.