Effect of Osmopriming Duration on Germination, Emergence, and Early Growth of Cowpea (Vigna unguiculata (L.) Walp.) in the Sudan Savanna of Nigeria

Seed osmopriming could be a sustainable method to increase crop establishment, uniform emergence, and growth of plant on the field. Laboratory and field studies were carried out in 2010 cropping season at Usmanu Danfodiyo University, Sokoto, to study the effect of seed osmopriming duration on the germination, emergence, and growth of cowpea seeds. Treatments consisted of three osmopriming duration (soaking in 1% KNO3 salt for 6, 8, and 10 hrs), one hydroprimed control (10 hr), and an unprimed control. These five treatments were laid out in a completely randomized design (CRD) replicated four times. The results showed that osmopriming with KNO3 for different durations was at par but was superior to unprimed treatments in terms of seed germination, emergence, plant height, and dry matter accumulation at 3 weeks after sowing. From this study, it can therefore be concluded that seeds of cowpea could be primed (both hydro and osmopriming) for increased performance. However, osmopriming with KNO3 salt (soaked in 1% KNO3 salt solution and dried before sowing) for 6 hours could result in greater seed germination and seedling height than hydropriming.