RESUMO
A field experiment was conducted during rabi 2022 at Zonal Agricultural and Horticultural Research Station, Brahmavara, Udupi, Keladi Shivappa Nayaka University of Agricultural and Horticultural Sciences, Shivamogga, on sandy loam soil to study the effect of different method of rice establishment and weed management options on yield and economics of paddy. The experiment was laid out in Factorial Randomized Complete Block Design with broadcasting and drum seeder method of establishment and five treatment combinations, replicated thrice. The study revealed that, the weed free treatment maintained by hand weeding recorded highest growth parameters and rice grain yield. The sequential application of pre-emergence herbicide pendimethalin 38.7 % CS @ 750 g a.i. ha-1 at 0-3 DAS (fb) early post-emergence application of bispyribac sodium 10 % SC @ 25 g a.i ha-1 at 13-15 DAS, recorded lowest total weed density (36.92, 31.73 and 40.45 No. m-2) at 15, 30 and 45 DAS, respectively and lower weed index (7.23%) under drum seeder method of establishment . The yield and yield attributing parameters like number of tillers (291.33 m-2), panicle length (19 cm), filled grains (89.33 panicle-1), grain yield (4221 kg ha-1) and straw yield (5387 kg ha-1) were observed in sequential application of pre-emergence herbicide pendimethalin 38.7 % CS @ 750 g a.i. ha-1 at 0-3 DAS (fb) early post-emergence application of bispyribac sodium 10 % SC @ 25 g a.i ha-1 at 13-15 DAS under the drum seeder method of establishment. The highest net return (? 82586 ha-1) and B:C ratio (2.81) was also recorded in the same treatment.
RESUMO
A field experiment was conducted to study the bio-efficacy of post emergent herbicides on weeds in direct seeded rice in medium black clay soil at Agricultural Research Station, Dhadesugur, University of Agricultural Sciences, Raichur, Karnataka during Kharif 2022. The experiment was laid out in Randomized complete block design with three replications. There were eight treatments consisting of five post emergent herbicides sprayed at 25 DAS, hand weeding at 20 and 40 DAS, weed free check and weedy check in direct seeded rice and the variety RNR 15048 was used in this trial. Application of cyhalofop butyl 5.1 % + penoxsulam 1.02 % OD @ 2000 ml ha-1 recorded significantly lower weed density, weed dry weight, weed index and higher weed control efficiency compared to all the other treatments. It also produced higher number of productive tillers (409.4 m-2), panicle weight (3.89 g), filled grains per panicle (243.1), lower number of unfilled grains per panicle (8.4), higher grain yield (6058 kg ha-1) and straw yield (6935 kg ha-1) in direct seeded rice. So it can be concluded that application of cyhalofop butyl 5.1 % + penoxsulam 1.02 % OD @ 2000 ml ha-1 at 25 DAS (weeds at 2-3 leaf stage) was most effective in managing the weeds with higher weed control efficiency. It also resulted in higher growth and yield components of direct seeded rice leading to higher grain yield.