Salicylic acid foliar spray promotes yield, yield components, and physiological characteristics in foxtail millet under drought stress

Drought is one of the major factors affecting plants' growth and development. , The application of plant hormones like salicylic acid (SA) is known to increase a crop's resistance to drought stress (DS) and help plants grow under drought conditions. Therefore, the present study aimed to evaluate the effect of salicylic acid foliar spray (SAFS) on yield and yield components of foxtail millet under different levels of DS. The present study reports the effect of SA foliar spray on yield and its components in foxtail millet Basten cultivar under drought stress conditions with three irrigation levels (45%, 65%, and 85% humidity of field capacity) as the main factor and four SA levels (0 to 2 mM) as the subplot. The results revealed that the fresh forage yield (36.76 ton/ha) and plant height (89.6 cm) were obtained from control and three mM SAFS treatments. The highest stem yield (6.971 ton/ha), leaf yield (4.947 ton/ha), grain yield (2.568 ton/ha), panicle length (18.7 cm), seed number per panicle (3670), 1000-seed weight (3.64 g) and several leaves per plant (11.43) were obtained by foliar spraying of 1.0 mM SA under normal conditions. The maximum harvest index (61.66%) was obtained under moderate stress conditions and 1.0 mM SA foliar spray. The highest levels of chlorophyll a, b, and total chlorophyll were 6.35, 4.02, and 10.37 mg/WW, respectively, from the treatment without drought stress and the application of 1.0 mM SA. The results showed that spraying 1.0 and 3 mM SA under stress and normal conditions improved yield components in foxtail millet Basten cultivar in Sistan weather conditions.