Productivity and Prolificacy in a Diallel Series of Market Sweet Corn Hybrids1

Abstract

The purpose of this research was to investigate the inheritance of prolificacy in a diallel series of sweet corn hybrids (Zea mays L.) and to determine the association of prolificacy with other attributes of productivity. Sweet corn has tended to be more prolific than dent corn. However, it is difficult for multiple‐eared hybrids to meet uniformity requirements for maturity, color, and kernel size because lower ears usually lag behind upper ears in development. Characters studied in addition to ears per plant (prolificacy) were percentage of usable ears, days to 90% silk, and performance rating (grade). General combining ability effects were highly significant for all characters, indicating the importance of additive gene action. Specific combining ability effects were highly significant for prolificacy, days to silk, and grade, emphasizing the importance of testing a wide range of hybrid combinations. Prolificacy was negatively associated with percentage of usable ears. Hybrids that initiated many ears had a comparatively low proportion that reached usable status. In view of this inverse relationship, selection against prolificacy is advisable in germplasm for market hybrids where productivity is measured in terms of usable ears per unit area. Use of a diallel series is well suited for evaluation purposes because all sweet corn hybrids are single hybrids involving only two parents.