A series of experiments were conducted to investigate aspects of seed quality.
A range of bread wheat genotypes important in South Australia were used for laboratory, greenhouse and field experiments. A preliminary set of field trials involving seed from eight different sources of each of eleven genotypes were evaluated at eight wheat growing locations in South Australia for two years.
Large seed, of course, contains more nutrients than small seed with which to nourish the embryo, but, mineral nutrient analyses of different seed sizes indicated that there were differences in nutrient concentration between seed sizes.
Again there were genotype differences and the patterns across genotypes varied for different minerals.
Two nutrients, zinc and manganese, were chosen for more detailed study because deficiencies of these nutrients are widespread in South Australia.
High levels of Zn and Mn in seed greatly improved crop growth especially in Zn and Mn deficient soils, in fact, seed high in Mn was more effective than Mn fertiliser in improving early growth and grain yield.It is concluded that sound healthy seed does vary in quality and this affects seedling vigour, crop establishment and grain yield.Seed source can affect genotype performance in evaluation trials.These results suggest that farmers would do well to manage their seed crops differently than grain crops especially by attempting to increase the levels of trace elements in the seed.The distribution of mineral nutrients within seed was examined in both high and low Zn content seeds of two genotypes and the remobilisation of nutrients was followed over the first twelve days after germination.Seeds from the outer florets of the middle spikelets of heads similarly had better quality than seeds from other positions.Wheat cultivar Machete accumulated more nutrients than other genotypes tested.Early vigour is achieved by sowing high quality seed and good management.Seed quality is a result of genotype and the growing environment of the mother plant from which it came.Using two dimensional spatial analysis techniques seed source was shown to be an important determinant of grain yield.Thus in genotype evaluation experiments, such as regional trials, where seed of genotypes may be derived from different sources changes in rank due to seed source could occur.