The confectionary type sunflower is used for human consumption (nut meats) and bird feed while the oil type is utilized as oil for human consumption and meal in livestock feed. Sometimes the oil type is used in bird feed mixtures. No processing plants are located in Ohio at this time. The nearest ones are in Georgia, Missouri, Minnesota, and Canada. Many sunflower are exported in the hull to world markets.
The sunflower grows well under a wide range of soil and climatic conditions. It is presently grown from North Dakota and Minnesota south to Texas in the mid United States. In addition, sunflower is grown in Indiana, Ohio, Michigan, Pennsylvania, and Georgia. Varieties presently grown were developed for dry climates in the Dakotas, Minnesota and Texas; however, breeders are selecting and testing their varieties in other parts of the United States as the demand for this crop increases.
This crop is normally planted between May 15 and July 1 in Ohio depending upon the soil conditions or other management concerns. Tolerance to cold and high temperatures contributes to sunflower adaptation in different environments. Seed will germinate at 42 degrees Fahrenheit (F) but a 50 degree temperature is more satisfactory. Temperatures must be 26 degrees F or lower for several hours to kill mature plants. Climatic conditions during seed development affect fatty acid composition of the oil which determines its ultimate human use.
The sunflower plant is not highly drought tolerant; however it has an extensive, heavily branched tap root system which permits it to extract more soil moisture than corn roots. Short periods of drought may not greatly reduce seed yield because growth can proceed at night when transpiration is low. The critical yield period occurs 20 days before and after flowering.
Sunflower plants grow well in soils ranging in texture from sand to clay. Because present yield potential and price per hundredweight (cwt.) do not compare economically with good corn and soybean yields, single crop sunflower should be considered on soils whose average soybean yield is 20 bushel or less and corn 100 bushel or less per acre. Properly managed on these soils, sunflower should yield 1500 to 1800 pounds per acre. Sunflower price to Ohio producers ranges from $8.00 to $12.00 per cwt. Since some country elevators will not purchase sunflower grain, arrange for a market before the crop is planted. Your seed supplier or County Extension Agent, Agriculture may be able to suggest some markets available to you. Grade I must weigh 27 pounds per bushel, have 10 percent maximum moisture and not over 5 percent dehulled seeds.
Any conventional corn planter or precision drill can be used for planting. Use plastic plates with filler rings matching the seed size indicated on the bag for plate planters. Some farmers have experienced difficulty when the small seed sizes were too small for the drum being used on air planters. Sunflower should be planted in rows to permit cultivation. Tennessee reports little yield increase when planting sunflower in narrow rows while Minnesota reports 20-30 inch rows outyielded 30-60 inch rows by 10 percent.
The ideal population may vary some with variety but populations similar to corn are appropriate. Row width should not be a factor in determining population. Soil yield potential and variety selection are more important.
Soil temperatures should be 50 degrees F or above when the seed is planted. This will probably occur in late April or early May under Ohio conditions. The seedling sunflower plant will tolerate lower temperatures but plant growth is very slow. Planting after July 1 may result in lower grain yields if climatic conditions are not ideal. Row direction has little effect on grain yield; however, prevailing winds may tend to lodge plants if rows are planted across the wind. The sunflower is phototropic (head faces east in morning and west in evening) in its vegetative growth while most heads face east after the flowers are open.
Seed should be planted 1 to 2 inches deep depending on soil moisture conditions. A sunflower may take longer to emerge than grain crops because of slow moisture penetration through the hull.
Sunflower fertility programs should be similar to corn and soybeans in regard to phosphorus and potassium. Apply 50 pounds of phosphorus and 100 pounds of potassium per acre. DO NOT exceed 100 pounds nitrogen per acre. These recommendations assume the soil nutrient level is not excessively low.
Early weed control is important. Use light tillage to destroy germinated and emerged weeds prior to planting. Consider applying a herbicide such as Treflan, Amiben, or Tolban. Sunflower seedlings are strongly rooted; consequently they can be harrowed during the 4 to 6 leaf stage. Postemergence harrowing should be done across the rows on a warm, sunny day to get best weed kill, and little crop injury because the sunflower plants are less turgid. Cultivate, if needed, when plants are 8 to 12 inches tall. Cultivation should not be closer to the row than plant leaf spread. Deep cultivation when plants are 1 to l-1/2 feet tall may drastically reduce yields.
Sunflower plantings in Ohio have few insect or disease problems. Experience from the Dakotas and Minnesota indicates the prudent producer will watch his field for insects and take appropriate action if they are found. Many insects are attracted to the field during flowering; therefore, insects should be properly identified before indiscriminately spraying. Disease problems should be verified by the Plant Disease Clinic (take sample to your County Extension Agent) for proper identification and control recommendations.
Gramoxone Super, a harvest aid desiccant, should be considered to remove moisture from the plants and make maturity more uniform. This harvest aid should be applied when the bottom of heads and bracts become lemon yellow in color.
Any conventional grain combine can be used for harvesting with the addition of a sunflower head attachment. Long gathering pans extending ahead of the cutter bar are used to salvage shattered seed. Ten seeds per square foot equals a harvest loss of 100 pounds per acre. The price of these attachments vary depending upon the size of combine head and manufacturer. Harvesting may start when grain moisture reaches 18-20 percent. Some moisture testers will not check sunflower moisture; however, Dickey-John and Farmi offer a special chart and adapters for their machines.
Combine cylinder speed should be as slow as possible and still thresh seed from the head (300 to 400 RPM). Concaves are usually set wide open and fan air flow reduced approximately 50 percent.
Some drying or air movement will probably be required during storage. Natural air with no added heat should be sufficient under most Ohio conditions. Grain should be 12 percent moisture for temporary storage and 9 percent for long time storage. Harvesting at a high moisture content (18 to 20%) normally results in higher yields, less bird damage and less shattering or dropping of heads than when seeds are harvested at a lower moisture content.
Most oil type varieties presently available are the result of hybridization. This means insects are not required for pollinization of the flowers even though they may be helpful. If harmful insects, e.g., head moth do become a problem, fields can be sprayed to control this insect. Hybrids permit increased oil and grain yields in addition to increased disease resistance.
Birds can be a problem if sunflower fields are planted near a flyway or roost. Scaring devices such as gas guns and shooting can be used to protect production fields.
Prepared by:
Walter H. Schmidt
Northwest District Agronomist Emeritus
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
TDD No. 800-589-8292 (Ohio only) or 614-292-1868