PRODUCTIVITY OF MAIZE RELATED TO THE CONTENTS OF RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE OXYGENASE, PHOSPHOENOLPYRUVATE CARBOXYLASE, AND CHLOROPHYLL

Contents of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), phosphoenolpyruvate carboxylase (PEPC), and chlorophyll in whole leaves were measured, and the productivity of maize plants was analyzed in relation to the content of these photosynthetic components. Results were as follows. 1) A very high grain yield (1,140 gm(-2) on dry weight basis) was achieved using high-yielding variety and slow-release fertilizer. In this treatment, the total dry weight and the amount of nitrogen absorbed in plants were also highest, and the dry matter increasing rate and nitrogen accumulation rate remained high during the maturation stage compared to other treatments. 2) High-yielding variety accumulated a larger amount of chlorophyll than variety with standard yield. On the other hand, the amount of Rubisco was affected by the nitrogen application, and the amount of PEPC was almost the same in both high yielding and variety with standard yield regardless of nitrogen application rate. Thus, to achieve high yield, chlorophyll content is the most important factor. 3) Amount of Rubisco and chlorophyll were higher in the case of slow-release fertilizer application than in rapid-release fertilizer application.