The shorter the rotation, the more important it becomes to select disease-resistant or tolerant varieties. If a field is already in row crop production, it is probably suitable for sunflower. The only situations likely to severely limit sunflower are poorly drained soils or soils that would prevent taproots from penetrating. Sunflower can tolerate pH values from 5.7 to 8.0. Choosing a variety Sunflower varieties have steadily improved over time.
Hybrids are the most common and normally have higher yields and higher oil percentage.
Most modern varieties are autogamous, able to produce seed without help from insect pollinators. Besides yield and oil percentage, traits to consider in variety selection include lodging and disease resistance, maturity, and seed size if the crop is for the snack food market. Field preparation Sunflower is more likely to be limited by nitrogen than any other nutrient. If nitrogen is limited, yields and oil percentage will be reduced. Research suggests sunflower is somewhat more sensitive to phosphorous than potassium.