Genetic Improvement in Grain Yield of Commercial Maize Hybrids Grown in Ontario from 1959 to 1988

摘要: The optimum plant density for total grain yield increased from old to more recent hybrids, but the increase in did not continue hybrids 1970s era of 1980s era. Approximately one-third genetic gain machine-harvestable can be attributed reduced stem lodging. A comparison oldest and most indicates that approximately 15% harvest index. Consequently, dry matter accumulation 85%