Ten Sunflower Planting Pointers
Sunday, April 15, 2007
filed under: Planting Systems
1. Paying attention to planter calibration and planter speed can go a long way to achieving a successful, uniform sunflower stand. The lighter test weight of sunflower amplifies what is often a key factor with the problem of planter skips and doubles – speed, especially a problem with plate and finger-type planters.
2. Commercial seed companies have plate recommendations for all seed sizes. Some equipment dealerships evaluate seed-metering units (or even seed, to match up planter plates) in the shop.
3. Seed flowability can be an issue with treated seed. Take note on whether your operator’s manual specifies to use a lubricant with treated seed, and if so, whether it should be graphite or talc – they are not interchangeable. Generally, talc is used in vacuum and air planters, and graphite in finger pick-up planters. Check your manual to know for sure.
4. Variances in per-pound seed count and/or seed shape can result in significant seeding error if you don’t recalibrate. Recalibrate every time you switch to planting a different variety, and even different seed lots of the same variety.
5. It’s generally recommended that sunflower be planted at a depth of 1.5 to 2.5”. If you’re planting at the furthest end of that range or deeper, consider planting a smaller seed size and increasing the planted population.
6. Plant about 10-15% above the desired final population, going with a lower rate if using treated seed. Aim for a final population of about 20,000-22,000 plants/acre for oils, and for the confection in-shell market that stresses seed size, 17,000-19,000 plants/acre. For the de-hull market, target a final population of about 18,000-20,000 plants/acre, and the bird food market, consider a final population of 21,000-23,000 plants/per acre. Planting rates are generally on the lower end in the High Plains, particularly dryland and confection production.
7. Sunflower needs to have excellent seed to soil contact. Because sunflowers have a woody hull, closure of the furrow becomes more important than for corn and most other crops.
8. At planting, check to make sure you’re knifing into the soil. Hairpinning – pushing chaff or straw into the seed slot instead of slicing through it – tends to be more a problem with air drills, particularly when seeding into no-till. Hairpinning is more of a problem when residue is wet – resolving the issue may be a matter of waiting until standing stubble becomes dry, and slicing through becomes easy. In other cases, you may need to sharpen drill discs/blades, or adjust down pressure.
9. Fill the seed boxes, plant a short distance, then stop and check seeding depth, downpressure, seed-to-soil contact, uniformity in seeding depth and seed spacing, and furrow closure.
10. When planting sunflower late (generally after June 10 in the Northern Plains) or replanting, use an early-maturing hybrid. The fact that sunflower performs well at lower populations suggests that replant is an option that might be best left for extreme early stand losses, especially in the shorter growing season of the Northern Plains. Some agronomists advise replanting only if a stand falls below a threshold of about 12,000 to 15,000 plants, or more than 25% of your yield goal. Otherwise, you’d be losing two weeks of crop maturity, and the successful establishment of the replanted crop isn’t a guarantee either.