3 Steps for Successful Variable Rate Seeding in Sunflowers

Like any crop, sunflowers can respond well to variable rate populations, provided you have enough variability in your fields. The trick, of course, is finding the right balance of plants per acre so you maximize yield potential.

The strategy for using variable rate seeding in sunflowers is similar to that of corn. If you’ve invested in equipment to plant other crops at variable populations, you probably already have what you need to do the same with sunflowers. Here are three steps to take if you’re looking to implement variable rate seeding on your sunflower acres.

1. Create Management Zones for Your Sunflower Acres

The best way to begin is to consult your local agronomist to help map out your fields and separate them into at least two or three different management zones. Together, you can analyze yield maps and historical satellite or aerial imagery to identify correlations and patterns. In areas of extreme variability, you might also consider mapping your fields with an electrical conductivity sensor, which measures the electrical current conducted by soil.

Your agronomist can input all of this information into a precision ag application such as the R7^® Tool to generate data on field performance potential for every acre, enabling them to recommend seeding prescriptions for each zone. Typically, this will mean increasing populations in the more productive areas of your fields and decreasing them in zones with lower performance, like hilltops.

A difference between using variable rate seeding in corn and sunflowers is that population swings are not as extreme from zone to zone with sunflowers. In my experience helping farmers fine-tune their seeding rates in southwestern North Dakota, they’ve had the most success when planting a maximum of 26,000 seeds per acre in the most productive areas of their fields. In the lowest-producing zones, getting down to populations around 18,000 seeds per acre has provided some great results. Whether you have two zones or five, staying within this range maximizes yield potential in each zone without compromising head size and stalk strength. Every field is different, so you need to put in the work to determine the best rates for your acres and continue to refine them.

2. Select the Right Sunflower Variety

Another important piece to consider is variety selection. For the best results, you’ll want to choose a product that won’t get too tall, and you’ll also want a product that has a good disease package. Choosing a variety that is prone to infections from diseases like Phomopsis, stalk rot or Sclerotinia can make your variable rate seeding experience an unpleasant endeavor.

In addition to optimizing overall yield potential, an added benefit of variable rate seeding is that it can help you achieve more uniform plant drydown across your fields. If stands in lower-producing areas of a field are overpopulated, there’s a good chance they will have smaller stalks and heads that dry down rapidly. But if the best-performing areas of a field are underpopulated, the plants will probably have larger stalks and heads that have much higher moisture levels. If you have both scenarios in the same field, harvest can become quite a challenge; however, planting the right populations across a field with variability can help prevent this from occurring.

3. Practice Variable Rate Fertility

Once you start planting your crop at different seeding rates, you should also consider variable rate fertility treatments. Fertility should be managed in the same way as population — apply more nutrients on the highest-producing zones and less on the less productive zones. Some farmers might get the added bonus of reducing their input costs by utilizing variable rate practices, while others will find that the costs stay the same because they end up redistributing seed and nitrogen to other areas of their field. Either way, the main objective of supplying the correct amount of seed and nitrogen to the right acres is to help optimize yield potential and overall profit potential.

If you’re planting sunflowers this spring and you’re curious about employing variable rate practices in your operation, contact your local WinField United retailer.

All photos are either the property of WinField United or used with permission.

© 2020 WinField United. Important: Before use always read and follow label instructions. Crop performance is dependent on several factors many of which are beyond the control of WinField United, including without limitation, soil type, pest pressures, agronomic practices, and weather conditions. Growers are encouraged to consider data from multiple locations, over multiple years, and be mindful of how such agronomic conditions could impact results. R7^® and WinField^® are trademarks of WinField United.