Indian mustard yield (Brassica juncea L.) in response to salicylic acid and clopyralid under rainfed and supplementary irrigation conditions

In order to evaluate the impact of salicylic acid on yield and yield component of Indian mustard under irrigation and non- irrigation and different doses of clopyralid, a field experiments was laid out in randomized complete block design with split-split plot arrangements having three replications were conducted at the research farm of East Azerbaijan Agricultural Research Center in 2019 and 2020. Irrigation levels (non-irrigation and supplementary irrigation) were assigned to main plots, salicylic acid levels (control without salicylic acid, priming of Indian mustard seeds with salicylic acid and foliar application with salicylic acid) were assigned to sub plots and different levels of clopyralid ((0 (weed free control), 0 (weed infested control), 0.4, 0.8 and 1.6 L.ha-1)) were allocated to sub-sub plots. The results showed that the application of clopyralid 0.4 L.ha-1 in non-irrigation condition resulted in highest number of pods per plant, number of seeds per pod, 1000 grains weight, and grain yield, and in this regard there was not statistically significant difference with weed free control. Maximum reduction in the number of pods per plant, number of seeds per pod, 1000 grains weight, and grain yield of this crop is related to treated plants with clopyralid 1.6 L.ha-1 and weed infested control under supplementary irrigation condition. Seed pretreatment with salicylic acid reduced the negative effects of clopyralid herbicide on Indian mustard plants grown from these seeds and increased the number of pods per plant, number of seeds per pod, 1000 grains weight, biological yield, grain yield, and harvest index.