With the 2025 sunflower crop now almost entirely harvested, many growers will be storing at least a portion on the farm. Here are some basic storage reminders, courtesy of the High Plains Sunflower Production Handbook.
While these recommendations were developed for High Plains sunflower producers, much of the commentary is applicable for Northern Plains growers as well. “Thank You” to Ken Hellevang, NDSU retired extension engineer and emeritus professor, for reviewing this article and suggesting several updates.
Clean the storage facility. Thoroughly clean the facility, aeration fan, ducts and handling system by removing trash and old grain which can harbor in-sects or fungi. Seal cracks and crevices that allow insects, fungi or moisture to enter the storage.
Consider using an approved bin treatment for insects. Treat the inside of the facility and beneath the plenum floor with a residual spray for insect control. Use only approved chemicals, follow label instructions, and make sure the chemical is registered for sunflower.
Clean sunflower. Sunflower stored with excessive trash, florets, broken seeds or other foreign material is more susceptible to fungi and insect problems. This trash is normally at higher moisture content and will cause heating. Cleaning the seeds also will improve the airflow through the sunflower.
Store at safe moisture content. Sunflower should be stored at 10% or less moisture if marketing within six months after harvest. Sunflower held through the spring or summer should be stored at 8% or less for oilseed and 10% or less for nonoil seed.
Don’t peak sunflower in the top of the bin. Peaking results in uneven airflow through a bin and inadequate cooling in the top of the bin. The peaked portion of the bin is an ideal place for insects and fungi to survive during storage and cause excessive damage.
Aeration systems are a key to stored sunflower management. Remember, an aeration fan is used to cool sunflower; not for drying or moisture removal. The target storage temperature is 40 degrees Fahrenheit or cooler. Fans should be operated when the outside air temperature is 15 to 20 degrees Fahrenheit less than the seed temperature. If the seed temperature is below the targeted storage temperature at harvest, the aeration fans still should run 24 to 48 hours to equalize the temperature and moisture inside the storage structure. Fans should be turned off during rainy or damp weather. A fan should be covered after it is turned off. Spring rewarming of sunflower is not necessary. In most bins, two to three days will be required to cool sunflower.
Check the seed. Sunflower should be sampled at least every two weeks after harvest or until seed temperatures are at winter storage levels. Then sample the sunflower every three to four weeks during winter and bi-weekly through the spring and summer. Many storage problems will appear during the first six weeks of storage or in the spring and summer as weather conditions begin to change.
Check the sunflower, not the bin! When sampling, probe the sunflower seed pile and be observant for temperature, moisture, insect, fungi and odor differences from the previous inspection. If the probe is hot, immediate action is necessary. Remember to feel, smell or walk around the bin and probe the sunflower and not just peer through a roof opening and assume there is no storage problem. Always write down the results of your inspection for future reference.
Act quickly to stabilize problems. If a problem is detected, try to stabilize it with aeration. If this fails, move the sunflower to market immediately, as the problems will only increase. Although some cooperators experience problems when storing sunflower, most are able to store seed successfully with good management. Growers who adequately dry seeds (8 to 9%) use aeration wisely and periodically inspect that their product do not have problems.