Coleoptile length and seedling emergencc wcre studicd in barlcy, oats, and wheat, u'ith four varieties for each crop. Significant As moisture cbnditions dictate var*ying depths of seeding, these-rcsults suggest that coleoptile length be considered in barley breeding programs.

ABSTRACT

These results serve to emphasizi the necessity of using seed of comparable quality in yield trials.

The competitive effect on yield of plants grown from large and small seeds was demonstrated in both greenhouse and field tests. Plants from small seeds yielded approximately 77 per cent of those grown from large seeds in the greenhouse and 57 per cent in the field with inter-plant competition; with inter-row competition the percentages were 70 and 54 respectively; and, with no competition, 89 and 83 per cent respectively. It was further shown that increased competition favoured plants from large seeds. Superior production resulted mainly from a greater number of heads on plants grown from large seeds.Suggestions are made as to how problems arising from this source of non-genetic variation could be overcome in various stages of selection.

Field experiments with three seed sizes and three seeding rates of each of three barley varieties were conducted in 1959 and 1960 at Edmonton and Lacombe, Alberta. Data were obtained on emergence, culm counts, grain yields, and 1000-kernel weights. Although there was no effect of seed size on emergence, the culm counts and yields were highest for large seed and lowest for small seed over all rates, varieties, and tests. The differences between yields from large and small seed decreased slightly as the seeding rate increased, but the seeding-rate × seed-size interaction was not statistically significant. There were varietal differences in yield response to seeding rates. It was, therefore, concluded that seeding rates in test plots should conform to those used in farming practice. The rate of seeding had a significant influence on 1000-kernel weights. The lowest rate produced the heaviest kernels and the highest rate produced the lightest kernels in each of four tests. Tillering capacity alone was a poor indicator of resulting yields. Results from further experiments, involving four seed categories of nine varieties in two tests, corroborated the above findings.