Effect of Chitosan on the Growth and Grain Yield of Rice Plant under Low - nitrogen Input Condition

Abstract

The experiment was carried out to determine the effect of chitosan (N-axetyl-β-D-glucosamin) on the growth and grain yield of the rice cultivar Khang Dan 18 in both summer and autumn cropping season in 2007. The plant was planted in single 0.071 m² pot. Each pot was applied with two nitrogen levels, viz.  0.36 g N (N1) and 0.50 g N (N2) with the same base of amount of 0.64 g P₂O₅ + 0.64 g K₂O per pot. The plants were sprayed with chitosan solution at the top-dressing stage (20 days after cultivation) with 4 concentrations: 0 ppm (control); 10 ppm; 20 ppm and 30 ppm. The results showed that with chitosan-treatment, both the growth duration and number of panicles per plant were not significantly effected whereas the plant height and leaf area were increased. Chitosan also increased chlorophyll contents, enhancing photosynthetic rate at both the panicle initiation and the heading stages. The yield components and grain yield of the plants were higher in chitosan treated plants than the control under low-nitrogen condition. It was found that chitosan concentration applied at 30 ppm manifested the highest yield (28.6 g grain/clump (N1) and 29.9 g grain/clump (N2)