Author(s): M. SENTHIVELU, D. KUMARESAN AND P. JAYAMANI

Abstract: To evolve agronomic and economically viable weed management methods for maximum weed control efficiency vis-à-vis the higher productivity of irrigated upland greengram, field experiments were conducted during the consecutive years of kharif 2015 and 2016 at Millet Breeding Station, Tamil Nadu Agricultural University, Coimbatore. The field experiments were laid out in Randomized Complete Block Design (RCBD) and replicated thrice with following weed control and weedy check treatments viz., T1-Pendimethalin 30EC @1.0kg a.i. ha-1at 3 DAS,T2-Pendimethalin + Imazethapyr (ready-mix) 32EC @ 1.0kg a.i. ha-1at 3 DAS, T3- T1 + Quizalofop-ethyl 5EC @ 50g a.i. ha-1at 15-20 DAS, T4- T2 + Quizalofop-ethyl 5EC @50g a.i. ha-1at 15-20 DAS, T5- T1 + Imazethapyr 10SL @40g a.i. ha-1at 15-20 DAS, T6- T1 + Hand weeding at 30 DAS, T7- T2 + Hand weeding at30 DAS, T8 - Hand weeding at 20 and 40 DAS and T9 - Weedy check. Among the various weed control methods attempted under field experiments, the least weed count of 4.11 Nos. m-2and weed dry weight of 36.5kg ha-1 at harvest stage was recorded in hand weeding twice at 20 and 40 DAS, and it was on par with the weed control methods of pendimethalin + imazethapyr (ready-mix) 32EC @ 1.0kg a.i. ha-1at 3 DAS + hand weeding at 30 DAS followed by pendimethalin @1.0 kg ha-1+ hand weeding at 30 DAS and significantly lesser than all the other weed control treatments.The maximum efficiency of weed control (87%) at harvest stage and consequently the higher grain yield (1247 kg ha-1) and gross return (` 60783 ha-1) was recorded in hand weeding twice at 20 and 40 DAS, whereas the higher net return (` 31202 ha-1) and benefit: cost ratio (2.13) was accounted in integrated weed control practice of pendimethalin + imazethapyr (ready-mix) @ 1.0kg a.i. ha-1 +hand weeding at 30 DAS, and it was on par with hand weeding twiceat 20 and 40 DAS, and pendimethalin @1.0kgha-1+ hand weeding at 30 DAS. It was concluded from the two years of experimental results that, weed control methods comprising of application of either pendimethalin + imazethapyr (ready-mix) 32EC @ 1.0kg ha-1or pendimethalin 30EC @1.0kg a.i. ha-1at 3 DAS followed by hand weeding at 30 DAS was the efficient and economically viable weed management practice for irrigated upland greengram. It was also concluded that under non-availability of labour for adopting hand weeding practice, pre-emergence application of pendimethalin + imazethapyr (ready-mix) 32EC @ 1.0kg ha-1 at 3 DAS followed by early post-emergence application of quizalofop-ethyl 50g ha- 1 at 15-20 DAS could be adopted as an alternate weed control methods for maximizing the productivity of irrigated greengram.

DOI: 10.22271/09746315.2020.v16.i2.1314

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