Differences in Crop Growth Rate , Chlorophyll Content Index and Nitrate Reductase in Source N of Sweet Corn

Abstract

A research to assess the interaction of nitrogen sources and doses of N in the growth and production as well as physiological effects of corn plants has been conducted in the Faculty of Animal and Agricultural Sciences, Diponegoro University, Indonesia. The research uses two sources of nitrogen namely NO3- (potassium nitrate) and NH4+ (ammonium sulfate), and doses of N (0, 50, 100 and 150 kg N/ha). The results showed that the dose of N fertilizer significantly effected on plant height, CCI, NR, CGR and weight of corn cobs. The interaction between the source of N and the dose of fertilizer N significantly effected on CCI, NR, and CGR, however, it had no significant effect on plant height and weight of corn cobs. The dose of N as much as 150 kg per ha resulted in plant height, CCI, NR, CGR and the highest cobs, respectively 82.33cm, 2.43, 84.3 umol, 18.87 g/day and 3538.2 g per plot. Keywords: sweet corn, chlorophyll content index, NR, CGR, corncob