Promising Bioregulators for Higher Water Productivity and Oil Quality of Chia under Deficit Irrigation in Semiarid Regions

Abstract

Appropriate water management practices are essential for the successful cultivation of chia in water-scarce situations of semiarid regions. This is highly essential when new crops such as chia are introduced for ensuring diversity and water saving. Therefore, field trials (2020–21 and 2021–22) were conducted to understand the impact of deficit irrigation and bioregulators (BRs) on the seed yield, water productivity, and oil quality of chia. The effect of foliar application of BRs such as thiourea (TU; 400 ppm), salicylic acid (SA; 1.0 mM), potassium nitrate (KN; 0.15%), potassium silicate (KS; 100 ppm), kaolin (KO; 5%), and sodium benzoate (SB; 200 ppm) were monitored at different levels of irrigation: 100 (I100), 75 (I75), 50 (I50), and 25 (I25) percent of cumulative pan evaporation (CPE). Deficit irrigation at I25, I50, and I75 led to 55.3, 20.1, and 3.3% reductions in seed yield; 42.5, 22.5, and 4.2% in oil yield; and 58.9, 24.5, and 5.7% in omega–3 yield, respectively, relative to I100. Bioregulators could reduce the adverse impact of water deficit stress on seed, oil, and omega–3 yield. However, their beneficial effect was more conspicuous under mild water stress (I75), as revealed by higher seed yield (4.3–6.9%), oil yield (4.4–7.1%), and omega–3 yield (4.7–8.5%) over control (I100 + no BRs). Further, BRs (KN, TU, and SA) maintained oil quality in terms of linolenic acid and polyunsaturated fatty acid contents, even under mild stress (I75). Foliar application of KN, TU, and SA could save water to an extent of 36–40%. Therefore, the adverse impact of deficit irrigation on seed, oil, and omega–3 yields of chia could be minimized using BRs such as KN, TU, and SA, which can also contribute to improved water productivity.

Effect of Deficit Irrigation and Intercrop Competition on Productivity, Water Use Efficiency and Oil Quality of Chia in Semi-Arid Regions

“…Further, being a precursor of jasmonic acid, omega-3 must have been consumed in the stress-signaling process, as reported by Sánchez-Martín et al [52] under water stress. A possible association between high canopy temperature and more saturated fatty acids such as fatty acid deterioration was also reported [53] in soybean and chia crop [31]. The data generated in the present experiment suggest that chia + fenugreek intercropping can produce quality oil in terms of oil content in seeds and omega-3 as well as in chia monocropping (Table 4).…”

“…Details of irrigation days, the actual quantity applied, and rainfall during the crop growth period are given in Table 1. Irrigation was applied to the crops treatment wise when CPE reached 100% and 50% of ETo equivalent, and irrigation time was calculated using the following formula [31].…”

Effect of Foliar Application with Putrescine and Benzyladenine on Vegetative Growth, Yield and Its Components and Seed Oil Contents of Chia (Salvia Hispanica L.) Plants Grown under Water Stress Conditions

“…Concerning the interaction effect between different foliar spray treatments and different water levels in Table ( Harisha et al, (2023) showed that deficit irrigation at 25, 50 and 75% ETo led to reductions in oil yield and in omega-3 yield in chia plant.…”