Weed Growth and Yield of Transplant Aus Rice (cv. Binadhan-19) as Influenced by Spacing of Transplanting and Level of Nitrogen

Abstract

An experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh from April to August 2019 to find out the effect of spacing of transplanting and nitrogen level on weed growth and yield performance of aus rice (cv. Binadhan-19). Four spacings of transplanting (25 cm × 15 cm, 25 cm × 10 cm, 20 cm × 15 cm and 20 cm × 10 cm) and four levels of nitrogen (control, 50% of RD, 100% of RD, 150% of RD and application of USG) were used in this experiment. The experiment was laid out in a randomized complete block design (RCBD) with three replications. Nine weed species belonging to five families infested the experimental field. Among the nine species three were grasses, three were broad leaves and three were sedges. Paspalum scrobiculatum, Echinochloa crusgalli, Digitaria sanguinalis, Oxalis europaea, Monochoria vaginalis, Nymphaea nouchali, Cyperus difformis, Scirpus juncoides and Fimbristylis miliacea were the important weeds in the experimental plots. The highest weed density at 20 DAT (14.43) and 40 DAT (17.40) were obtained from spacing of 20 cm × 15 cm and 20 cm × 10 cm, respectively. Control treatment showed maximum weed densities (15.08 and 18.41, respectively) at both sampling dates. The highest weed density (16.67) was recorded from the treatment combination of 20 cm × 10 cm spacing with control treatment at 20 DAT and the highest weed density (19.66) was recorded from treatment combination of 20 cm × 10 cm spacing with 150% of RD of nitrogen at 40 DAT. Spacing of 20 cm × 10 cm gave the highest (3.54 t ha-1 ) grain yield compared to other spacings. The highest number of grains panicle-1 was found in 20 cm × 10 cm spacing compared to other spacings used in the study. The highest grain yield (3.89 t ha-1 ) was recorded from application of USG, which was significantly higher than other nitrogen levels. The 20 cm × 10 cm spacing produced the highest grain yield (4.41 t ha-1 ) with application of USG, whereas 20 cm × 15 cm with no nitrogen (control) treatment produced the lowest grain yield (2.39 t ha-1 ). So, it can be concluded that 20 cm × 10 cm spacing of transplanting with application of USG may be used for maximization of yield of Binadhan-19 in aus season.