Effect of herbicide and nitrogen on yield of scented rice (Oryza sativa) under different rice cultures

Abstract

An experiment was conducted to find out the effect of herbicides and nitrogen on yield of scented rice (Oryzo sorivo L.) under different rice cultures. Under transplanted rice, weed population and their dry weight were significantly lower, whereas effective tilleres/m2, grains1 panicle and grain yield of rice were significantly higher than under direct-seeded puddled rice. Application of 120 kg Nlha significantly increased the yield attributes and yield as well as weed population and their dry weight compared with 60 kg Nlha. Under both transplanted and direct- seeded puddled rice cultures hand-weeding caused maximum decrease in weed population and their dry weight and increase in yield attributes and yield. However, effect of herbicide treatments was not alike. Herbicides were found more effective under transplanted rice. Butachlor (1 .O kglha), anilofos (0.5 kg/ha) and clorimuron ethyl (0.012 kgha) caused almost identical decrease in weed population and their dry weight and resulted in significant increase in yield attributes and yield of rice compared with weedy check. Chlorimuron ethyl was found more effective against broad- leaved weeds. Effect of herbicides under direct-seeded puddled rice was not as palpable as in transplanted rice. Neither herbicides nor nitrogen caused noticeable change in the grain-quality characters, viz. hulling, milling and head-rice recovery (%), grain length, breadth and length : breadth ratio, before and after cooking in any year.