Cultivars and method of application influences the effect of silicon on incidence and damage of phloem feeders, induction of defense reaction, attraction of natural enemies and yield in black gram (Vigna mungo L.)

Abstract

Silicon, a quasi-essential nutrient element, is well known for imparting tolerance to various biotic and abiotic stresses in crops. The present studies were carried out to evaluate the effect of silicon with two methods of application viz., soil drenching and foliar application against phloem feeders under field conditions for two seasons on two different black gram cultivars. Among the cultivars, Vikral responded better to silicon treatment (orthosilicic acid) than Pratap Urd 1 with reference to in reduction of population of phloem feeders and enhancement of defence enzyme activity, silicon uptake, total sugars and total phenols and yield in both the seasons. Among the application methods, soil drenching (2 mLL− 1 of OSA) proved to be the superior method of administration to record significantly low population of phloem feeders, increased activity of defence enzymes and total sugars, total phenols content, improved activity of coccinellids and yield in both the seasons. However, it holds good with foliar application (2 mLL− 1 of OSA) method. Both silicon application methods of OSA were significantly superior than insecticidal check and untreated control treatments. Deposition of Si was the highest in the leaves of black gram (1.541%) when OSA was administered through soil than foliar (1.451%) and untreated control (0.891% endogenously available Si). Highest benefit: cost ratio recorded in soil drenching of OSA @ 2 mLL− 1 (1.88 and 1.93) surpassed BC ratio of recommended insecticidal check (1.65 and 1.72) during winter and summer seasons, respectively. Both the application methods of OSA proved significantly superior over insecticidal check with respect to management of phloem feeders in black gram including enhanced grain yield, coccinellids activity and induced biochemical defence as well as lowest cost of cultivation, which can be easily incorporated with other practices for eco-friendly, sustainable management of phloem feeders in black gram.