Effect of cinnamic acid on germination, seed vigor, some physiological traits, seed yield and yield components of cowpea plants (Vigna unguiculata) from unaged and aged seeds

Low quality of seeds resulting from seed deterioration is of major concerns underlying reduction in both quality and quantity of production in agricultural sector. Therefore, applying compounds like CA to alleviate seed aging deleterious effects and eventually to ensure final crop yield is important. Effects of five different CA on germination percentage and seed vigor were assessed as a factorial based on completely randomized design in seed lab of plant physiology group in Wageningen University.  Effects of three different concentrations of CA on physiological traits, yield and yield components of cowpea plants from seeds with different primary qualities were assessed in a two-year field experiment as factorial based on completely randomized blocks in three replications. Results indicated that CA had no significant effect on germination of unaged seeds, but concentrations of 15 and 30 µM improved seed vigor. In aged seeds CA pretreatment induced a 13-percent (45 and 60 µM) and 38-peercent (45 µM) in germination and seed vigor, respectively. Assessed characteristics differently responded to CA application based on their primary seed quality. So that when the CA application improved a trait, the trait was reduced in plants of different seed primary quality. In total, CA foliar application in plants from aged seeds was more effective to enhance yield and yield components while the reverse result was obtained for plants from unaged seeds.In case of dry matter accumulation, aged seed pretreatment was more effective than foliar application while a reverse result was obtained for plants from unaged seeds.