Effect of micronutrients, rhizobium, salicylic acid, and effective microorganisms in plant growth and yield characteristics of green gram [Vigna radiata (L.) Wilczek] in Rupandehi, Nepal

Nepal has a very diverse topography and ecosystem, with mountains in the north and lush plains in the south. Despite the diverse ecology, the production of green gram is still in its minority. This experiment was conducted to assess the effect of micronutrients (Zn, B, Mo, Co, and Mn), rhizobium, effective micro-organisms, and salicylic acid in plant growth, yield, and yield attributes of green gram [Vigna radiata (L.) Wilczek] in Rupandehi district of Nepal in March 2021. Pratikshya variety of green gram was used as a test crop. Different levels of ZnSO4 and Borax, Ammonium Molybdate, Cobalt Nitrate, MnSO4, effective microorganism, Mixture, Salicylic acid, and Rhizobia along with control constituted treatments. Various application methods were used for applying treatments including soil incorporation, seed priming, inoculation, and foliar application. The results revealed that leaf area index, number of branches, number of pods per plant, and yield were significantly different (P < 0.05). Among various treatments, the mixture was found most effective in the case of grain yield (1048.1 kg ha(-1)), stover yield (2472.7 kg ha(-1)), biological yield (3520.8 kg ha(-1)), harvest index (31.2%), and the number of primary branches (4.9). Likewise, the number of secondary branches (6.86) was better with Borax@10 kg ha(-1). There was no significant difference in the plant height, number of pods per plant, pod length, pod weight, number of grains per pod, and test weight between different treatments. ZnSO4 @ 25 kg ha(-1) was found to have an impact on the number of mature, immature, and total pods per plant. Overall, the study concluded that the mixture of all micronutrients performed better in terms of grain yield while zinc sulphate had great potential for plant growth parameters which could improve the farmers' livelihood. It is recommended to conduct multi-location trials in a larger domain.