Studies were undertaken by a number of collaborating institutions to investigate aspects of the role of genotype and interactions with pre-planting seed hydration (seed priming) on the weed competitiveness/tolerance of maize and rice. Laboratory experiments at the University of Wales confirmed that priming hastens time to germination of both crops. A series of field trials, carried out subsequently in Zimbabwe, investigated the effect of maize genotype and priming on crop yield across a gradient of weed pressure. This was achieved by allowing weeds to compete with the crop for varying periods. The dominant effect in all trials was time of weed removal. Priming had a significant, positive effect on yield in only one of four trials. Discussions with farmers indicated that primed seed is often used for gap-filling when emergence is poor or for planting onto residual moisture on vlei fields. It is rarely used or planting entire topland fields.
Riches, C. Cultivar competitiveness and interactions with on-farm seed priming for integrated weed management. Final Technical Report. Natural Resources Institute, University of Greenwich, UK (2001) 61 pp.