Effects of seed priming and water potential on seed germination and emergence of wheat (Triticum aestivum L.) varieties in laboratory assays and in the field
Poor crop establishment is a major problem in wheat production due to low soil moisture. Two experiments were undertaken to determine the effects of seed priming on seed germination and seedling emergence of wheat varieties. The first experiment determined the effects of water potentials (0, -0.01, -0.1, -0.2, -0.5 and -1.5 MPa), seed hydro-priming treatments including non-primed, primed (without seed drying), primed and 12 h drying on seed germination of wheat varieties. The second experiment determined the optimum seed soaking duration in wheat for maximum emergence. The factors used were seed treatment (soaking for 0, 1, 2, 4, 8, 12, 16, 20 and 24 h and 12 h soaking and 12 h drying) and variety. In the first experiment, there was a significant (P < 0.01) interaction between seed treatment and water potentials. Seed germination percent for all the treatments decreased as water potentials decreased. The non-primed seeds had the greatest decrease in germination percent as water potential was lowered. At low water potentials (-0.2 and -0.5 MPa), priming improved the germination of all the varieties. In the second experiment, there was a significant (P < 0.05) seed treatment effect on wheat emergence. Priming resulted in an increased final percent emergence and lower time to 50% emergence when compared with the non-soaked seed. It was concluded that priming wheat seed up to 12 h may be recommended were soil water potential is low enough to limit emergence. Delay of planting after soaking for 12 h did not affect the final emergence.
Key words: Seed priming, wheat, water potential, germination rate.