SITUATION

FACTORS TO CONSIDER

• Crop rotation benefits
• Optimum planting date
• Double crop options
• Taproot system
• Drought and cold temperature tolerance
• Special production needs

ACTION PLAN

1. Know when to plant double crop sunflowers. Planting should begin as soon as wheat is harvested. Planting dates vary by location, from around late June in Oklahoma to mid-July across much of Kansas. Check with your local agronomist for specific planting dates.
2. Evaluate crop advantage. Sunflowers are less affected by drought-like conditions and are more cold tolerant than soybeans or grain sorghum. They also perform better on marginal soils as well as soils with pH over 8.
3. Understand the taproot advantage. The sunflower has an extensive taproot system. Taproots penetrate deeper than fibrous root systems of grass crops such as wheat, corn and grain sorghum. This allows a sunflower crop to utilize deep moisture and fertility that other crops cannot reach. If the soil profile is filled through irrigation or with natural moisture prior to planting, optimum yields can be achieved.
4. Use cold tolerance to produce more bushels. With any double crop system, it is a race for the second crop to reach maturity before it is shut down by freezing temperatures. Most crops stop development at 32 F or colder. However, sunflowers can tolerate temperatures as low as 27 F for several hours, allowing plants to utilize more weeks of growing season compared with other crops.
5. Manage double crop sunflowers. Insect pests are a major production consideration with any sunflower crop, but later planting can reduce insect pressure. Several cutworm species and wireworms that can attack seedlings are rarely a problem with late-planted sunflowers, as soils tend to be very warm and the surface dry. Stem weevils and sunflower head moths are also less of a problem. Late sunflowers miss the early moth flights and often need only one application, if any, for head moth control.

SUMMARY