You’ve raised a big crop of sunflowers — one of the best in history for many producers. Now the challenge is to successfully store the seed until you sell it. Ken Hellevang, North Dakota Extension agricultural engineer, offers the following storage tips:
• Successful sunflower seed storage requires attention to details.
• Monitor both the pile temperature and the moisture levels.
• Use aeration fans to keep your seeds in good condition.
• Pull the sunflower fines out of the center of the bins. Fines tend to concentrate in the center if a distributor was not used. Because fines usually are wetter than the seed, they are prone to spoiling. Also, fines will restrict airflow and limit cooling in the bin center.
• Watch moisture levels. Oil sunflower should not be stored above 10% moisture during the winter and 8% during the summer. Non-oil sunflower should not be stored above 11% moisture during the winter and 10% during the summer. Oilseed sunflower’s resistance to fungal infection during storage at 10% moisture is equal to wheat’s resistance at 15% stored moisture.
• Cool sunflowers for storage over winter to 25 degrees F in the Northern Plains and to 40 degrees in the Southern Plains. Operate fans when the outside air temperature is 15 to 20 degrees lower than the seed temperature. If the seed temperature is below the targeted storage temperature at harvest, the aeration fans should run 24 to 48 hours to equalize the temperature and moisture inside the storage structure. Fans should run even during periods of intermittent high humidity. They can be turned off and covered during rainy or damp weather. In the Northern Plains, you will have to run fans to warm up the sunflowers. In the Southern Plains, re-warming is not necessary.
• Level off the peaks in the bins. Moisture and heat accumulate in the peak due to moisture migration. This can cause crusting and spoilage and increase insect infestations.
• Check bins initially every two weeks for roof moisture condensation, pile crusting and pile temperature changes. Any of these conditions could indicate the presence of mold or insects. If the sunflower seed starts to heat, cool the pile. Check bins monthly after the seed has been cooled to the target temperature.
Sources: “Sunflower Production Hand-book,” North Dakota State University, and “High Plains Production Handbook,” Kansas State University
This article published in the January, 2010 edition of DAKOTA FARMER.
All rights reserved. Copyright Farm Progress Cos. 2010.