The influence of sowing date and biostimulants foliar spray on yield and yield components of chickpea ( Cicer arietinum L.)

Abstract

Abstract Chickpea ( Cicer arietinum L.) is a key rainfed crop in western Iran, whose productivity depends heavily on optimal sowing dates and biostimulant use. This study evaluated the effects of sowing date and foliar application of biostimulants on seed yield and yield components of desi chickpea. The study employed a factorial randomized complete block design with three replications across two locations in Kermanshah Province, Iran, in 2024–2025. Treatments consisted of three sowing dates (February 19, March 5, and March 21) and four foliar biostimulants applications (control, seaweed extract, amino acid, and a growth‐promoting biofertilizer). The highest number of pods per plant (33.41) and the greatest 100‐seed weight (17.08 g) were obtained from the March 5 sowing date at the Kermanshah site. Foliar application of seaweed extracts increased pods per plant and 100‐seed weight by 87.36% and 61.41%, respectively, compared with the control at Salas‐e Babajani. The maximum seed yield (1216.67 kg ha − 1 ) and aboveground biomass (2892.33 kg ha − 1 ) were achieved with the combination of the March 5 sowing date and seaweed extract application at Kermanshah, representing 3.28‐ and 3.64‐fold increases, respectively, relative to the late sowing (March 21) control treatment at the Salas‐e Babajani site. The highest seed protein content (25.70%) resulted from amino acid application at Salas‐e Babajani on February 19. Seaweed extract applied on March 5 at Kermanshah also resulted in high protein content (23.76%). Optimizing sowing dates combined with these foliar biostimulants can substantially enhance chickpea yield and seed quality under western Iran's rainfed conditions.