Effect of Seed Inoculation, Weed Management and Foliar Nutrition in Rice Fallow Blackgram for Higher Productivity in Cauvery Delta Zone of Tamil Nadu

Field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai during 2021-22, 2022-23 and 2023-24 to find out suitable bio inoculant, weed management practice and foliar nutrition for Rice fallow blackgram.

The experiments were carried out by using RCBD (Factorial) with three replications. The treatments viz., Seed inoculation [A₁-Control (no seed inoculation), A₂-Rhizobium + PSB (local), A₃-LSMR 1 + RB 3 microbial consortia], Weed management [B₁-Weedy check, B₂-Propaquizafop 2.50 % + imazethapyr 3.75 % ME @ 125 g ha^-1 at 15-20 DAS, B₃-Fomesafen @ 220 g ha^-1 + fluzifop-p-butyl @ 220 g ha^-1 at 15-20 DAS] and Foliar nutrition [C₁-Water spray at flower initiation and pod initiation stage, C₂-Nano urea spray @ 0.25 % at flower initiation and pod initiation stage, C₃-19:19:19 NPK @ 2 % at flower initiation and pod initiation stage].

The lower weed density, weed dry weight and higher weed control efficiency was recorded with application of early post emergence herbicide fomesafen + fluzifop-b-butyl @ 220 g ha^-1 at 15-20 DAS. Seed inoculation with LSMR1 + RB3 microbial consortia, application of fomesafen + fluzifop-b-butyl @ 220 g ha^-1 at 15-20 DAS and foliar nutrition with 19:19:19 NPK @ 2 % at flower initiation and pod initiation stage had taller plants, higher pods plant^-1, more seeds pod^-1 and test weight which led to higher grain yield. Due to increase in blackgram yield, the same treatment achieved higher gross return, net return and benefit cost ratio.