Valtcho D. Zheljazkov1, Brady Vick2, Brian Baldwin3, Normie Buehring, M. Wayne Ebelhar, Tess Astatkie4, Thomas Horgan5, and Billy Johnson6. (1) North Mississippi Res & Ext Center, Mississippi State, 5421 Highway 145 S, Verona, MS 38879, (2) USDA-ARS, P.O. Box 5677, Fargo, ND 58105, (3) Box 9555, Mississippi State University, Mississippi State University, Dep. of Plant & Soil Sciences, Mississippi State, MS 39762, (4) Department of Engineering, Nova Scotia Agricultural College, 50 Pictou Road, Truro, NS B2N 5E3, Canada, (5) North Mississippi Research and Extension Center, Mississippi State University, 5421 Highway 145 South, Verona, MS 38879, (6) Coastal Plain Experiment Station, Mississippi State University, 51 Coastal Plain Road, Newton
Sunflower (Helianthus annuus L.) is not a commonly grown crop in southeastern US. However, recent research has demonstrated the potential for sunflower to be grown as a cash crop in the region. Field experiment was conducted in 2007 to evaluate the effect of N (0, 67, 134, and 202 kg ha-1), seeding date (May, June, and July), and hybrid (DKF3875, DKF2990, DKF3510 and DKF3901) on seed yield, oil content, and oil composition of sunflower grown at five locations in Mississippi (Newton, Starkville, Stoneville, and two locations in Verona). Overall, the first seeding date was the most successful and resulted in relatively good seed yields from all sunflower varieties in all locations. Yields and oil content and composition from the second seeding date were acceptable. Due to the drought conditions in early summer, the third seeding date did not establish in some locations, and the yields were low. Oil content and composition was mostly affected by hybrid and seeding date than by the N application rate. In general, higher N rates resulted in lower seed oil concentration but in increased seed yields. The results from this study indicated that the tested sunflower hybrids can be a viable crop in most parts of Mississippi for production of cooking oil or biodiesel. Further research may be needed to establish the optimal seeding rate for various sunflower hybrids and for a better weed control in sunflower in southeastern US.