Production factors in the tropics.

Abstract

During the period when there is a closed green crop canopy and the plants remain vegetative, comprising about 40% of the total life cycle, annual crop plants accumulate about 80% of their ultimate dry weight. It is argued that the optimum life period of annual crops in the tropics from the standpoint of seed yields never exceeds about 7 months, which is the approximate length of the growing season in the temperate zone. Average daily radiation during the growing season in the temperate zone is about 1.5 times as much as that in the tropics. In some tropical crop plants, e.g. rice, high temperatures tend to reduce the total amount of carbohydrate translocated into the grain. Soil conditions and temperature both tend to be more favourable in the temperate zone. Highest actual and potential yields in the tropics are obtained with perennial crops.-R.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)