Soil applied potassium enhanced the oil contents in hybrid mustard crop under water deficit condition

Mustard is an important oil seed crop and plays vital role in boosting the country economy especially in Pakistan. Unfortunately, under the sudden fluctuation in the climatic conditions, water stress is one of the most drastic factors restricting its production. To mitigate the water scarcity impact, soil applied potash has emerged as a sustainable approach in improving the crop oil production. For this purpose, two years filed trials were conducted at the Agronomic field research-area, Department of Agronomy, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Multan, Pakistan during two consecutive growing seasons 2017-18 and 2018-19. The Randomized Complete Block Design was used with two factorial arrangements having three replications. Different factors were Fa; irrigation water stress i.e. (no stress (control)), stress at vegetative stage (Sveg), stress at vegetative & reproductive stages (Sveg+rep)) and Fb; potash application i.e. (0, 30, 60 and 90 kg ha-1) at the time of sowing. Mustard hybrid (45S42) was used as a test specie. Observations shown that water stress at Sveg resulted in grain yield reduction (47%) as compared to control. In the case of potash fertilizer treatments particularly at 60 kg ha-1 was significantly alleviated the detrimental effect (15% in yield-related components) of water stress both in Sveg and Sveg+rep conditions as per control. Nevertheless, potash application at 60 kg ha-1 depicted increase of oil-contents (35%) as per with other treatments under the applied irrigation water stress at Sveg and Sveg+rep conditions during the both years of trials. Based on the results of economic analysis, potash application at 60 kg ha-1 is an easy, efficient, commercially feasible and cost-effective agronomic approach for compensating the adverse effects of water stress in mustard crop.
Key words: Hybrid mustard; Irrigation water stress; Oil contents; Potash