Distribution of photosynthate in rice plants : 1. Distribution of dry matter between ear and shoot of several varieties grown under different time of cultivation.

Abstract

In a field experiment long-term varieties yielded greater total dry weight than short-term varieties but had similar dry weight of ear and grain yield to short-term varieties except a few treatments, and the dry weight ratio of ear to shoot or grain yield to total dry weight was greater for short-term varieties than for long-term varieties at maturity. A positive correlation coefficient was found between the dry weight ratio of ear to shoot at maturity and the ratio of dry weight produced after ear emergence to dry weight at ear emergence, number of spikelets per unit dry weight at ear emergence, RGR. or NAR. during ripening stage. A negative correlation coefficient was found between the dry weight ratio of ear to shoot at maturity and dry weight at ear emergence or number of days from transplanting to ear emergence. These facts might be ascribed to that the weight of ear was determined by the amount of dry matter produced after ear emergence or the number of spikelets and that there was no definite relation between dry weight produced after ear emergence or number of spikelets and dry weight at ear emergence, in case of varieties and transplanting dates being different.