A field experiment was conducted during rainy (Kharif) seasons of 2019 and 2020 to assess the efficacy of the sequential application of pre- and post-emergence herbicides for managing complex weed flora in line sown sesame (Sesamum indicum L.) at Agriculture Research Sub-Station, Sumerpur, Pali. There were nine weed control treatments replicated thrice in a randomized complete block design. Hand weeding twice recorded the highest values of growth parameters and seed yield (1.25 t/ha) which was at par with pre-emergence application (PE) of pendimethalin 750 g/ha followed by (fb) quizalofop-p-ethyl 40 g/ha at 20 days after seeding (DAS). The uncontrolled weeds in weedy check caused 50% sesame seed yield reduction. The post-emergence application (PoE) of quizalofop-p-ethyl 40 g/ha at 20 DAS and sequential application of pre-emergence application (PE) of pendimethalin 750 g/ha PE followed by (fb) quizalofop-p-ethyl 40 g/ha at 20 DAS recorded the highest weed control efficiency, sesame seed yield, net return and benefit cost ratio and were observed to be superior than the recommended practice of pendimethalin 1000 g/ha PE fb hand weeding at 25 DAS.

An investigation was carried out to evaluate the effect of weed management on yield, yield attributes and eco- nomics of direct seeded rice (Oryza sativa L.) and herb of grace or brahmi [Bacopa monnieri (L.) Pennell] inter- cropping system at Pantnagar, Uttarakhand, during rainy seasons of 2015 and 2016. The lowest weed density, dry weight and the highest weed-control efficiency were recorded with pendimethalin followed by (fb) cyhalofop- butyl fb 1 hand-weeding 45 days after sowing (DAS) or days after planting (DAP) in 2 : 1 row ratio. Dry-herbage yield of brahmi (2.07 and 2.35 t/ha) and grain yield (5.30 and 6.56 t/ha) were highest in sole direct-seeded rice (pendimethalin fb cyhalofop-butyl fb 1 hand-weeding at 45 DAS/DAP) and sole brahmi (3 hand-weedings 30, 45 and 60 DAP). The highest land-equivalent ratio was found with pendimethalin fb cyhalofop-butyl fb 1 hand-weed- ing at 45 DAS or DAP in alternate row ratio (1 : 1) of direct-seeded rice and brahmi during both the years. The higher net returns and benefit: cost ratio were found with pendimethalin fb cyhalofop-butyl fb 1 hand-weeding at 45 DAP in alternate row ratio (1:1) of rice and brahmi intercropping system.

A field experiment was conducted in a factorial randomized block design during the rainy (kharif) season of 2013 at Pantnagar, Uttrakhand, to study the influence of different planting geometry and weed-management prac- tices on weed and crop dynamics in direct seeded aerobic rice (Oryza sativa L.). Continuous drilling at 20 cm with pendimethalin as pre-and bispyribac-Na as post emergence herbicide supplemented with 1 hand-weeding 45 days after sowing provided excellent results. Echinochloa colona (2.04 +0.71) recorded the maximum summed dominance ratio. Among the planting geometries, continuous drilling at 20 cm and among weed-control practices, pendimethalin (1,000 g a.i./ha) + bispyribac-Na (25 g a.i./ha) + 1-hand-weeding 45 days after sowing (DAS) pro- vided the higher weed-control efficiency (87.4%), productivity ( 4.79 t/ha) and net benefit ( 40,633/ha).

The efficacy of selected herbicides along with the planting geometry for weed control in direct seeded rice was evaluated under tropical conditions of Pantnagar during rainy season of 2013. Pendimethalin (1kg active ingredient (a.i.) ha-1 3 days after sowing) + bispyribac-Na (25g a.i. ha-1 28 days after sowing) + one hand weeding at 45 days after sowing and bispyribac-Na (25g a. i. ha-1 28 days after sowing) + one hand weeding at 45days after sowing had a mean grain yield of 47.95 and 37.68 while continuous drilling at 20cm and 20 x 10cm had a mean grain yield 34.72 and 34.14 qha-1 , respectively which is significantly superior than wider (25 x 25cm) spacing. Wider spacing (25 x 25cm) among planting geometry and weedy check among the weed control treatments resulted in higher uptake of nitrogen. Among the spacing, continuous drilling at 20cm and Pendimethalin (1kg a.i. ha-1) + bispyribac- Na (25g a.i. ha-1) + one hand weeding at 45 days after sowing among weed control practices proved most profitable with net returns of ` 40576 ha-1 and ` 40633 ha-1 and benefit:cost ratio of 1.7 and 1.8, respectively. It was revealed that all the weed control treatments were superior to weedy conditions.