Vol. 11, Issue 9 (2022)

Author(s):
AM Rathod, TU Patel, Rutul S Patel and Dhwani Bartwal

Abstract:
A field experiment was conducted at the College Farm, Navsari Agricultural University, Navsari (Gujarat) during summer seasons of 2019-20 and 2020-21. The experiment was laid out in split-plot design and replicated four time. Three crop establishment methods were assigned to main plots viz. S₁- Direct Seeded Rice, S₂- Conventional Transplanted Rice, S₃- Sprouted Seed (Line sowing) whereas five weed management practices in sub-plots within each main plot viz. W₁- Weedy check (Control), W₂- 2 HW at 20 and 40 DAS/T, W₃- Pretilachlor 50% EC 1000 g ai/ha (Pre) fb Bispyribac sodium 10% SC 25 g ai/ha at 30 DAS/T, W₄- Pyrazosulfuron-ethyl 10% WP 15 g ai/ha (Pre) fb Bispyribac sodium 10% SC 25 g ai/ha at 30 DAS/T and W₅- Pretilachlor 50% EC 1000 g ai/ha (Pre) fb Chlorimuron ethyl + Metsulfuron methyl 20% WP 4 g ai/ha at 30 DAS/T were evaluated on rice cv. NAUR-1. The total weed density (grasses, broad leaved weeds and sedges) and weed dry biomass at 20 and 40 DAS/T were significantly reduced under Conventional transplanted rice (S₂) than other establishment methods of rice (S₁- Direct seeded rice and S3- Sprouted seed line sowing). The Conventional transplanted rice (S₂) had also inferior weed seed counts after crop harvesting on top layer of soil than as compared to remaining establishment methods of rice. Among weed management practices, the total weed density was enhanced at 40 DAS/T over their intensity at 20 DAS/T under Weedy check (W₁), while it declined at 40 DAS/T with application of Pretilachlor 50% EC 1000 g ai/ha (Pre) fb Bispyribac sodium 10% SC 25 g ai/ha at 30 DAS/T (W₃), Pretilachlor 50% EC 1000 g ai/ha (Pre) fb Chlorimuron ethyl + Metsulfuron-methyl 20% WP 4 g ai/ha at 30 DAS/T (W₅) and Pyrazosulfuron-ethyl 10% WP 15 g ai/ha (Pre) fb Bispyribac sodium 10% SC 25 g ai/ha at 30 DAS/T (W₄). The higher weed seed count/kg of top layer soil was obtained extensively under weedy check (W₁) than other four weed management practices.