EFFECT OF PLANTING METHODS AND HERBICIDES ON THE YIELD AND YIELD ATTRIBUTES OF AMAN RICE cv. BRRI dhan33

Abstract

An experiment was carried out at the Agronomy Field Laboratory, Department of Agronomy, Hajee Mohammad Danesh Science and Technology University, Dinajpur during the aman season (July to December), 2011 to study the effect of planting methods and herbicides on the yield and yield attributes of aman rice cv. BRRI dhan33. The experiment was laid out in a split plotdesign with three replications accommodating planting methods in main plot and weed control measures in sub ploy Twelve species of weeds belonging to seven families prevailed in the experimental field were Echinochloa colonum L., Marsilea crenata L., Monochoria hastata L., Scirpus mucronatus L., Alternanthera sessilis R.Br., Ludwigia prostrata L. and Eclipta prostrata L. The effect of different planting methods and weed control measures on the weed density and weed dry weight and the yield and yield attributes were significant. Among the weed control measures application of pre-emergence herbicide (rifit) + one hand weeding at 42 DAS/DAT had the lowest weed density and weed dry weight. The highest weed density and weed dry weight was obtained from control (no hand weeding +no herbicide) treatment {7 he yield attributes were significantly influenced by planting methods and weed control measures/The total tillers m~’, effective tillers m?, grains panicle”, spikelets panicle’, 1000-grain weight (g), grain yield (t ha’'), straw yield (t ha’), biological yield (t ha’'), harvest index (%) were significantly higher in direct seeding by drum seeder than those of direct seeding by hand and transplanted rice. /The highest number of total tillers m”, effective tillers m?, grains panicle”, spikelets panicle’, 1000- grain weight, grain yield (3.55 t ha’), straw yield, biological yield were found when the test crop was weeded by application of pre-emergence herbicide(rifit) application + one hand weeding at 42 DAS/DAT/The treatment of control (no hand weeding + no herbicide) performed the lowest (1.933 t grain ha’'). In direct seeding by drum seeder, crop duration was shortened by 12 days compared to transplanting method. The relative profitability of direct seeding by drum seeder planted rice was Tk. 46257.9 ha’ over the transplanted rice because of higher grain yield in the former case. Direct seeding by drum seeder planted rice with application of pre-emergence herbicide (rifit) application + one hand weeding at 42 DAS/DAT appears to be a promising technology in controlling weeds in aman rice in aman season (cv. BRRI dhan33) and may be adopted in our country.