Effect of Seed Hardening and Pelleting on Growth, Yield, Physiology and Resultant Seed Quality of Cowpea under Natural Saline Conditions

Background: Cowpea (Vigna unguiculata) is one of the most important legume crops cultivated throughout the world. Cowpea is used as food, feed, forage, fodder, green manuring and vegetable. It's seed is a nutritious component in the human diet, as well as for livestock. Seed hardening and pelleting are seed enhancement techniques used to improve seed germination and seedling vigour and growth by altering the physiological state of the seed. This alteration may improve the vigor or the physiology of the seed by enhancing uniformity of germination. Seed enhancement techniques like hardening and priming include use of chemicals that trigger systemic acquired resistance or improve stress tolerance whereas the pelleting treatments improve seed handling and planting. They also enhance nutrient availability or provide inoculates by delivering materials needed during sowing, germination and seedling establishment. Hence in order to study the combined effect of seed hardening and pelleting on growth, yield and resultant seed quality of cowpea under natural saline conditions, the present study was taken up. Methods: The present field and laboratory investigations were carried out to study the effect of seed hardening, seed pelleting and their combined effect on growth, physiology, yield and resultant seed quality of cowpea under natural saline conditions. The fresh seeds of cowpea seeds cv. CO (CP) 7 were hardened with KCl @ 1%, CaCl2 @ 1% and both KCl and CaCl2 @ 1% and then the hardened seeds were further pelleted with pungam leaf powder @ 100, 150 and 200 g kg(-1) of seed. Then the treated seeds were evaluated for their seed productivity and resultant seed qualities using untreated seeds as control. Observations on growth, leaf chlorophyll content, gas exchange parameters, yield and resultant seed quality parameters were recorded. Result: The experimental results revealed that among the treatments, seeds hardened with KCl @ 1% + CaCl2 @ 1% and pelleted with pungam leaf powder @ 200 g per kg recorded higher growth, yield parameters, leaf chlorophyll content, gas exchange parameters and resultant seed quality when compared to control and other treatments.