Effect of seed priming on agronomic performance and cost effectiveness of rainfed, dry-seeded nerica rice
Priming is a seed enhancement method that might improve seed performance under stress conditions such as drought, freshly harvested or aged seeds. A field experiment was conducted in randomized complete block design in 2009 and 2010 at the Research Farm of the University of Calabar, Calabar, Nigeria to evaluate the effect of a range of priming techniques on agronomic performance of New Rice for Africa (NERICA), and to quantify their benefits to farmers. Treatments were on-farm priming, hydropriming, Osmopriming, vitamin (Ascorbate) priming, hardening, osmohardening, and a non-primed control. Results of variance of analysis showed that seed priming had significant effect on germination, seedling emergence, days to heading, duration to plant maturity, number of tillers, number of fertile panicles and grain yield (p=0.05). However, plant height at maturity and weight of 1000 grains were not similarly affected. Ridicule protrusion (germination) and seedling emergence consistently occurred sooner in primed seeds compared to non-primed seeds, but differences existed between priming methods. The time to 50% germination was least in hardened, hydro-primed, on-farm-primed, and Ascorbate-primed seeds compared with other priming methods evaluated, and percentage seedling emergence followed the same pattern. Primed seeds gave plants that matured significantly earlier than the unprimed ones, with hardened, hydro-primed, and on-farm primed seeds not differing statistically significantly. The grain yield from hardened, hydro-primed, and on-farm primed seeds was highest and statistically similar, but higher than that of other priming methods studied. Based on net returns, the most cost- effective priming method for NERICA rice is hardening, followed closely by on-farm priming and hydropriming.
Keywords: NERICA rice, seed priming, germination, seedling emergence, Nigeria