EFFECT OF RATE AND TIME OF NITROGEN APPLICATION ON THE GROWTH AND YIELD OF AUS RICE CV BR26

Abstract

field experiment was conducted at fi) Agronomy Field Laboratory, Department of Agronomy, Hajee Mohammad Danesh Science and Technology University, Dinajpur during the period from March to July 2007. The study was aimed at determining the effect of rate and time of nitrogen and their interaction on BR26 Aus rice. There were twenty treatment combinations consisting of five rates of nitrogen (0, 30, 60, 90, and 120 kg N/ha from Urea) and four levels of time of nitrogen application (T1, T2, T3 and T4), ‘replicated three times within a Randomized Block Design, The effect of nitrogen rate was significant for both the grain and straw yields. Nitrogen rate increased grain yield up to 60 kg/ha and no further response achieved. The rate of increase of yield was much higher (40%) at 30 kg/ha of nitrogen compared to the control (1.95 t/ha) and retarded (43%) at 90 kg N/ha. On the other hand, straw yield increased up to 90 kg N/ha and decreased at 120 kg N/ha. Of the yield components, effective tillers/hill, number of filled grains /panicle and 1000 grain weight increased significantly up to only 60 kg/ha of nitrogen. The increased in grain and straw yields due to nitrogen rate was supported through the increased in growth parameters as monitored in leaf area index (LAI), crop dry matter/m? and tillers/hill. Time of nitrogen application was not significant for grain yield but some differences among treatments were observed for filled grains/ panicle, straw yield and growth parameters like dry matter/m” and LAI \A significant interaction between rate and time of nitrogen application was obuarvedl in the application of 60 kg N/ha in three equal splits which produced the highest grain yield (3.64 t/ha). |