The Response of Grain and Oil Production and Water Productivity of Sesame to Limited Irrigation Under the Conditions of Vermicompost Application

A field experiment was carried out at the research field of Payame Noor university of Shadegan, Khuzestan province during 2021-2022 growing season to evaluate the grain and oil production of sesame under deficit irrigation in response to vermicompost application. The experiment was conducted as split-plot in three replications, where irrigation treatments (I1: full root zone irrigation and I2: partial root zone irrigation) were allocated to main plots and vermicompost (0.0, 5.0, 10.0, 15.0 and 20.0 t ha-1) were assigned as sub plots. Results indicated that oil percentage, grain and oil yield of sesame were reduced 3.0%, 17.7% and 23.9% under partial root zone irrigation, respectively. Significant reduction (P≤0.01) of grain number and grain weight under partial root zone irrigation (30% and 11.2%, respectively) showed that grain yield of sesame was affected by both components of grain yield. However, grain number was more sensitive to water shortage compared with grain weight. Water consumption in the limited irrigation treatment was reduced by 49.2%, and this caused the water productivity for seed and oil production to increase by 61.7% and 49%, respectively, compared to the full irrigation of the root system. The use of vermicompost fertilizer led to the improvement of sesame grain and oil yield and their related traits, so that with the consumption of 20 t ha-1 of fertilizer, the grain and oil yield increased from 791 to 1248 kg ha-1 (57.8% increase) and 374 to 657 kg ha-1 (75.7% increase), respectively. Therefore, the use of vermicompost fertilizer can help to improve the yield of sesame seeds and oil under limited irrigation conditions.