Yield and Quality of Semidwarf and Standard‐Height Sunflower Hybrids Grown at Five Plant Populations1

Abstract

AbstractInformation on yield and agronomic performance of semidwarf sunflower (Helianthus annuus L.) is limited. The objectives of these field studies were: (i) to acquire information on seed yield and other agronomic characteristics of two semidwarf and two standard‐height sunflower hybrids; and (ii) to determine an optimum plant population for hybrids representing both plant types. Two experimental semidwarf (SD) and two standard‐height (SH) hybrids of similar maturity from Cargill and Sigco research breeding programs were grown at populations of 32 123,49 420,66 717,84 014, and 101 311 plants/ ha over a 3‐yr period (1982‐1984) under dryland conditions at Fargo, Carrington, and Prosper, ND. Yield differences were observed dependent on the hybrid but not on plant type. The Cargill SD and Cargill SH genotypes had similar but higher yields than both 894 SH, a commonly grown hybrid, and Sigco SD, which were not significantly different from each other. Yield differences among hybrids were the consequence of differences in seed weight and seed per head. Cargill SH had the highest oil percentage and test weight. It was concluded that the semidwarf hybrids did not possess any yield superiority when compared to the two standard‐height sunflower hybrids. A plant population of 32 123 plants/ha resulted in the highest yield for hybrids representing both plant types. Plant populations above 32 123 plants/ha decreased yield, seed weight, seed per head, and head diameter, but increased percent oil.