Identifying the Optimum Planting Date and Density for Sunflowers in the Southern Great Plains.

In the Southern Great Plains, winter wheat (Triticum aestivum L.) has been grown continuously in many areas which has led to an increase in weed pressure and decreased profitability.   Sunflowers (Helianthus annuus L.) offer a viable rotation crop with the development of an in-state market.  The objective of this study was to determine the optimum planting date and density for sunflower production in Oklahoma.  Sunflowers were planted at two locations in OK with six different planting dates at five populations.  Dates ranged from early April through late July.  A seeding rate of 20,000 seeds per acre was used.  Yield was determined by combining the middle two rows of each plot.  A subsample was collected to determine moisture, test weight, and oil content.  Results have shown that optimum planting date for sunflowers has been from late April through early July, depending on weather conditions.  The results should provide useful, relevant information for producers in Oklahoma and the Southern Great Plains for an alternative rotation crop.