July has arrived and our field season is in full swing! At Cherry Research Farm in Goldsboro, NC and Oxford Tobacco Research Station in Oxford, NC we have three studies focusing on best management practices for organic high-oleic sunflower.
The majority of U.S. sunflower is grown in the High Plains, mainly in North Dakota and South Dakota, but the Southern Piedmont has a compatible climate and many compatible rotations for sunflower production. This is especially true for organic systems.
Sunflower is a relatively low-input crop and nitrogen has been demonstrated to be a major limiting nutrient in sunflower production. While supplying enough nitrogen is key; overapplication of nitrogen has been connected to reductions in yield through lodging and increased disease susceptibility (Best Practices for Sunflower Production, Chapter 7: Fertilizing Sunflower, South Dakota State University). Overapplication of nitrogen has also been associated with decreased oil content which may hurt producers who could get a premium for higher concentrations of oil. Our nitrogen rate study in Goldsboro and Oxford is comparing a split application of 0, 50, 100, 150, 200, and 250 lbs N/acre as well as treatments of Crimson Clover and Hairy Vetch as green manure.
In this year's variety trial we are evaluating six different varieties; CP455E, N4H470 CLP, N4H521 CL, Hornet, P42N21, P51W21 at two planting dates; early May and mid June. At the end of the season we'll compare yield, oil-content and quality, as well as resistance to sunflower moths for each variety at these two planting dates.
Our density study will compare yield and oil quality of planting populations of 7,000, 10,000,13,000, 16,000, and 19,000 plants/acre.
We look forward to sharing the results of these three studies and giving updates throughout the season.
If you are interested in hearing more about this work; we'll be having our 2023 Organic Commodities Field Day in Goldsboro, NC on July 18th from 8:30 AM-12 PM. To register visit our Eventbrite page 2023 Organic Commodities Field Day.
