Abstract
SUMMARY: The effect of seed protein content on grain yield has been studied in varieties of spring barley, oats and wheat grown under differing cultural conditions. Grain yield was affected by seed protein content in one experiment where very low yields were attained, but the effects were inconsistent. No effect was observed in two other experiments made in a glasshouse and the field. In a growth-room experiment, seed with high protein content produced more vigorous seedlings than low-protein seed; these differences were accentuated by increasing seedling age at very low nutrient levels, but decreased with seedling age at normal nutrient levels. It is concluded from the results that variations in seed protein content are unlikely to have a significant effect on yield under practical conditions.