The research work was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during aman season from July to December, 2015 to study the effect of nitrogen fertilizer and weed management on the growth and yield of transplant aman rice cv. BRRI dhan46. The experiment consisted of four fertilizer treatments viz. 0 kg N ha −1 (N 0 ), 40 kg N ha −1 (N 1 ), 80 kg N ha −1 (N 2 ) and 120 kg N ha −1 (N 3 ) and four weeding treatments viz. one hand weeding at 20 DAT (W 1 ), two hand weedings at 20 and 35 DAT (W 2 ), three hand weedings at 20, 35 and 50 DAT (W 3 ), weeding by Japanese rice weeder twice at 20 and 35 DAT (W 4 ) and unweeded control (W 5 ). The experiment was laid out in randomized complete block design with three replications. The highest plant height (113.00 cm), number of total tillers hill −1 (8.74), number of effective tillers hill −1 (6.18), panicle length (21.98 cm), number of grains panicle −1 (114.20), grain yield (4.00 t ha −1 ), straw yield (5.25 t ha −1 ) and biological yield (9.25 t ha −1 ) were recorded in N 2 (80 kg N ha −1 ) treatment. The lowest plant height (106.00 cm), number of total tillers hill -1 (7.20), number of effective tillers hill −1 (5.00), panicle length (20.70 cm), number of grains panicle -1 (97.60), grain yield (3.52 t ha −1 ), straw yield (4.46 t ha −1 ) and biological yield (7.97 t ha −1 ) were recorded from N 0 (No nitrogen fertilizer control) treatment. On the other hand, the highest grain yield 4.23 t ha −1 was observed in three weedings condition because of the highest number of effective tillers hill −1 (6.81), number of grains panicle −1 (111.10). The highest straw yield (5.51 t ha −1 ) was also found in three weeding condition. The lowest grain yield (3.40 t ha −1 ) was recorded in W 5 (unweeded control) treatment. The lowest straw yield (4.31 t ha −1 ) was also observed in W 5 (unweeded control) treatment because of the smallest plant (106.97 cm) and lower number of total tillers hill −1 (7.20). Therefore, 80 kg N ha −1 along with three hand weedings at 20, 35 and 50 DAT may be used for obtaining the highest grain and straw yields of BRRI dhan46.

Sustainable agriculture requires the use of environmentally friendly management practices. Mulching is one of the most effective methods that can play a positive role in weed management, improving soil properties as well as increasing crop production. A field experiment was conducted at the research farm of National Maize Research Program (NMRP), Rampur, Chitwan, Nepal during winter season, 2016. The experiment was carried out in single factor randomized completely block design comprising of nine weed management methods with four replications. Data regarding the weed population, weed dry weight, yield attributes and yield were recorded during the study. Different weed management practices showed significant differences on weed dynamics and weed control efficiencies. Black polythene mulch and silver black mulch was found more effective to reduce total weed density and dry weight during whole crop season and remain comparable with other polythene mulch too. The effect of weed management practices observed on weed density and dry weight were reflected on grain yield. The highest grain yield was recorded in silver black plastic mulch (4537.50 kg ha-1) followed by black plastic mulch (4068.20 kg ha-1), clear plastic mulch (4065.22 kg ha-1), green plastic mulch (3834.84 kg ha-1) and weed free (3222.74 kg ha-1) which were comparable to each other. At tasseling-silking stage among plastic mulch treatment, the higher moisture conservation observed on the black plastic mulch followed by clear plastic mulch, green plastic mulch and silver black plastic mulch. While comparing of plastic mulch with dead mulch, moisture on dead mulch remain higher than plastic mulch after 90 DAS. Thus, in humid subtropical region of western Chitwan, Rampur, the maize can be successfully cultivated by using different color of polythene mulch.