EFFECTS OF SUPPLEMENTARY N ON THE QUALITY AND LEVELS OF GRAIN PROTEINS IN RICE

The effects of supplementary URAN-N (urea-ammonium-nitrate), applied e ither to the soil or as a foliar spray, on dry weight, crude protein l evel and main protein fractions of rice (Oryza sativa L.) grain were s tudied under greenhouse conditions. URAN (20 kg of N/ha) applied at di fferent times before, during and after anthesis, increased crude prote in levels in grains. Later URAN applications caused larger protein inc reases. No difference in crude protein level were observed between fol iar spray and soil applied URAN. A negative correlation was found betw een crude protein level and grain weights. The levels of albumin+globu lin were not affected by N applications. Glutelin was the fraction tha t contributed most to the protein increase in grains. A negative corre lation was found between the levels of prolamin and glutelin, showing that increases in protein levels due to supplementary N results in inc rease in the protein quality of rice grains.