Seeds Stored into Spring Still Require Monitoring
Thursday, April 1, 1999
filed under: Harvest/Storage
Sunflower producers don't need an additional task during an already-hectic spring schedule. But if you're still holding sunflower seeds in storage, you owe it to yourself - and your pocketbook - to keep a diligent eye on those seeds.
"We had more sunflower go into storage last fall than normal," North Dakota State University extension ag engineer Ken Hellevang noted earlier this spring. "Also, a lot of row crops went into storage with higher moisture levels than we'd like to see. Now that outside
temperatures have warmed, any existing problems will intensify."
North Dakota Grain Inspection Service (NDGIS) personnel can verify those concerns. By mid-March, they'd already observed significantly more heat-damaged sunflower than they would normally expect at that time of year. "I have seen both elevators and farmers - many of whom I consider extremely conscientious - take some substantial discounts on
'flowers" they were delivering, reported Lori Grieger, NDGIS station manager at Enderlin, N.D.
"I am sure that had the market followed a more-typical pattern, many of those seeds would have been sold in the 'dead of winter.' That not being the case, I believe there is a lot of sunflower in the country hat is likely to go out of condition this spring if not watched
Though several weeks of spring weather already will have passed by the time this issue of The Sunflower is distributed, any sunflower seeds remaining in storage still need to be monitored during the warmer late spring. The quality of those seeds can be adequately maintained by remembering a few storage basics, Hellevang points out.
First, the recommended grain temperature for storage into the spring and summer months is about 40 degrees. Keeping fans and aeration ducts covered helps to maintain the cooler bin temperatures by preventing warm winds from blowing into the structure.
The maximum recommended moisture content for oil-type sunflower seed stored into this time of year is eight percent - which is roughly equivalent to 13-percent moisture wheat. (Storing sunflower at 10-percent moisture is similar to trying to store wheat at 15 percent.)
When checking stored seeds' temperature and moisture content, be sure to do so at several locations within the bin, Hellevang emphasizes. "For the most accurate moisture test, place grain samples in sealed bags and allow them to warm to room temperature before measuring the moisture content," he advises.
"Grain that exceeds recommended storage moisture contents must be dried before the grain warms," the North Dakota drying/storage specialist emphasizes. Remember, too, that grain near the top of a bin may be warmer than outside air temperatures due to solar heating of the roof, he adds.
As temperatures heat up, so does the potential for mold and insect problems in seeds with moisture contents that are excessive for warm-season storage. "We'll begin seeing insect activity when the grain reaches about 50 degrees Fahrenheit," Hellevang notes. "If those
problems are severe, we'll need to consider some kind of fumigation to control those pests. Unfortunately, we can't get effective fumigation results until all the grain in a bin gets up to around 60 degrees.
"Problems frequently can be reduced by keeping grain cool," Hellevang concludes. "Seeds at the top of a bin can be cooled by pushing cool air (up to 50o F) up through the grain for a few hours. Normally, temperatures are lowest at sunrise." - Ruth Isaak