Das, SwarnalataDas, Manali2017-08-032017-08-032017-08TH- 4793http://krishikosh.egranth.ac.in/handle/1/5810027256Cowpea (Vigna unguiculata (L.) Walp.) is an important legume vegetable crop of India. Its quick growth and rapid ground cover have made cowpea an essential component of sustainable subsistence agriculture in marginal lands. The present investigation was undertaken to study the effect of storage duration on primed cowpea seeds in addition to priming response of cowpea seeds to halo, hormonal and hydro priming. The experiment was conducted at the Department of Seed Science and Technology, college of Agriculture, Orissa University of Agriculture and Technology, Bhubaneswar. The experiment was conducted in a completely randomised design with four replications. Fresh seeds and 18 months old cowpea seeds were primed with potassium chloride (KCl, 1%), potassium nitrate (KNO3, 1%), gibberellic acid (GA3, 50ppm), salicylic acid (50ppm) and deionised water for 6 hours. Primed seeds were stored upto 45 days under normal room temperature. Seed samples from the respective treatments were drawn at 15 days intervals and subjected to test the physiological and biochemical parameters. Observations were recorded on germination %, root length, shoot length, seedling length, shoot:root length ratio, seedling dry weight, SV-I, SV-II, electrical conductivity, alpha amylase and total dehydrogenase activity. In case of old cowpea seeds all the priming treatments produced higher germination than non primed seeds and the increase in germination count was 31.0 %, 17.9 %, 6.6 %, 15.1 % and 35.8 % when seeds treated with KCl, KNO3, Salicylic Acid, GA3and hydro priming respectively; the halo priming agent KCl recorded the highest SV-I value (3313.49); hydro priming exhibited the highest SV-II value (4161.95); non primed seeds recorded the highest EC value (0.801 dS/m) and hydro priming recorded the lowest value (0.597 dS/m); alpha amylase activity was more pronounced in seeds primed with KCl (0.446); the highest dehydrogenase activity was observed in seeds treated with deionised water (383.4 μg/ 20 ml/hr). In case of fresh seeds KNO3 showed the highest germination count (89.5 %); seeds treated with KNO3 produced the highest SV-I value (4416.60); seeds treated with deionised water produced the highest SV-II value (4645.80); salicylic acid recorded the highest EC value (0.651 dS/m); alpha amylase activity was more pronounced in seeds primed with KCl (0.462); the highest dehydrogenase activity was observed in seeds treated with KCl (590.0 μg/ 20 ml/hr).With the increase in post-priming storage duration all the physiological parameters started decline both in old and fresh primed and non primed seeds. But the primed seeds showed better quality parameters as compared to non primed seeds at different storage durations. The efficacy of priming treatments in old seeds was judged by calculating germination response index (GRI), vigour response index (VRI) and biochemical response index (BRI). Hydro priming and KCl have high GRI, VRI and BRI values as compared to other treatments and salicylic acid has the lowest GRI, VRI and BRI values. Hydro priming has the highest SQI value (25) followed by KCl (24) and GA3 (22). This result indicates that hydro priming is the best priming treatment followed by KCl and GA3. Old cow pea seeds primed with KCl and deionised water could be stored in ambient environment up to 50 days as per the prediction model. From the present investigation it may be concluded that hydro priming and the halo priming agent KCl (1 %) could improve the seed quality parameters of old cowpea seeds to a satisfactory levelennullThesis