On-farm seed priming with water is a low-cost, low-risk technology that is easily adopted by
resource-poor farmers. It increases the yield of tropical and subtropical annual crops in marginal areas by a
combination of better crop establishment and improved individual plant performance. The effects of seed priming,
i.e. soaking seeds overnight in water before sowing, on plant growth and development are consequences of faster
germination, emergence, and more vigorous early growth. Results from in-vitro, on-station and on-farmexperiments
are discussed.
Recent work has tested opportunities for resource-poor farmers to use seed priming as a vehicle for applying
biofertilisers (Rhizobia). Preliminary results from field experiments suggest that these interventions are very
effective over and above the already demonstrated benefits of priming with water alone. In a pot experiment
using chickpea, combining a Rhizobium inoculation with seed priming significantly increased nodulation but had
little effect on yield. Nevertheless, the results confirmed that Rhizobium inoculation is compatible with on-farm
seed priming.
Observations in the field have shown that some primed crops show enhanced resistance to disease, either as a
consequence of increased vigour, altered phenology, or due to some more fundamental mechanism associated with
exposure of seeds to anaerobic conditions during priming. Priming seeds of a highly susceptible cultivar of pearl
millet in water for 8 h before sowing significantly reduced the incidence of downy mildew in artificially infected
seedlings from 80% to less than 60%
