Impact of Moisture Deficit on Physiological Quality of Maize Seeds

There is limited empirical information on the physiological basis of the development of seed quality despite the awareness that vigorous seeds provide a basis for solving cropestablishment problems. To address this problem, seeds of 16 maize (Zea mays L.) genotypes were planted in the dry season and the crop was grown entirely under irrigation. In one of the blocks, irrigation was suspended from five weeks after planting to harvest, whereas the control plot received irrigation from planting to physiological maturity. The seeds produced under the irrigated and moisture deficit conditions were harvested and subjected to seed viability and vigor tests as well as to seedling-evaluation tests. High-yielding genotypes did not necessarily produce seeds with high vigor. Moisture deficit resulted in 34% loss in germination potential, whereas vigor loss was between 40% and 220%, depending on the type of vigor test used. The seeds produced under moisture deficit had slow and non-uniform germination and seedling growth, with poor storage potential. Water availability to the crop affected seed vigor more than the genotypic effect, suggesting an inelastic limit to the extent that genotype can compensate for inadequacy of moisture of a maize plant