Vol. 11, Issue 11 (2022)

Field studies were conducted at the IRS of Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj (Allahabad, Uttar Pradesh, India) for two consecutive seasons; November 2020 to April 2021 and November 2021 to April 2022 to investigate the effect of irrigation scheduling based on water limiting conditions on crop growth, yield and yield response factor for mustard (varuna T-59). Treatments consisted of five irrigation schedules viz., the I1 (irrigation at zero percent water stress of 60 mm designed depth of irrigation), I2 (irrigation at 20% water stress of 60 mm designed depth of irrigation), I3 (irrigation at 40% water stress of 60 mm as designed depth of irrigation), I4 (irrigation at 60% water stress of 60 mm as designed depth of irrigation) and I5 (Irrigation at 80% water stress of 60 mm as design depth of irrigation water).

The experiment was conducted in Random block design with three replications. All the growth, yield attributes and yield parameters were increased significantly with I3 treatment (irrigation at 40% water stress of 60 mm as designed depth of irrigation) which was significantly superior over rest of treatments. For calculation of yield response factor dependent variable, actual crop yield and independent variable including climate data were obtained from Metrological department of SHUATS (Prayagraj, UP) between 2020-2022. Potential evapotranspiration calculated by Penman-Monteith method. Actual evapotranspiration (ETa) based on irrigation scheduling was calculated at the field. Yield response factor (Ky) was obtained for five water limiting conditions viz., irrigation at 0%, 20%, 40%, 60%, 80% water stress of 60 mm as design depth of irrigation i.e. 60mm, 48 mm, 36 mm, 24 mm and 12mm depth of water respectively. The yield response factor (KY) was obtained by relative yield decreases to relative crop water use deficit (water stress) by regression analysis. The relative yield decreases of the mustard crop with increases in evapotranspiration deficit (water stress). It shows the response of yield with respect to the decreases in water consumptions. Yield response factor for mustard crop was determined as 1.23, 0.70, 0.29, 0.60, 0.75 for treatments I1, I2, I3, I4 and I5 (average of both year 2020-21 and 2021- 22). The yield response factors developed in this study could be used in irrigation design and scheduling for mustard in the study area.