Proper Storage: The Basics
Monday, September 1, 2008
filed under: Harvest/Storage
Editor’s Note: The following comments on proper storage of sunflower are excerpted from the High Plains Sunflower Production Handbook. As such, they are reflective of the climactic conditions of eastern Colorado, Kansas, southern Nebraska and adjacent areas. A few items have been edited slightly to also pertain to the Northern Plains production region.
• Clean the Storage Facility — Thoroughly clean the facility, aeration fan, ducts and the handling system by removing trash and old grain, which can harbor insects or fungi. Seal cracks and crevices that can allow insects, fungi or moisture to enter the storage.
• Consider an Approved Bin Treatment for Insects — Treat the inside of the facility and beneath the plenum floor with a residual spray for insect control. Be sure the chemical is registered for use with sunflower, and follow label instructions closely.
• Clean Trashy Sunflower — Sunflower stored with excessive trash, florets, broken seeds, weed seeds or other foreign material is more susceptible to fungi and insect problems. Such trash normally is at a higher moisture content and will cause heating. Cleaning the seeds also improves airflow through the sunflower.
• Store at a Safe Moisture Content — Sunflower should be stored at 10% or less moisture if the plan is to market the crop within six months following harvest. Sunflower seeds held through the spring or summer should be at 8% or less for oil-types and 10% or less for nonoils.
• Aeration Systems Are Key — An aeration fan is meant to cool the sunflower seeds; it is not intended to be a method of drying or moisture removal. The target storage temperature is 20 to 40 degrees F., within 20 degrees of the average coldest winter month. Fans should be operated when the outside air temperature is 10 to 20 degrees less than the seed temperature.
Fans may run even during periods of intermittent high humidity. They can be turned off during rainy or damp weather, however. A fan should be covered after it is turned off.
• Check the Seed — Sunflower should be sampled weekly until seed temperatures are cooled to the winter storage temperature. Then sample the sunflower every three to four weeks during the winter — and weekly, if the seeds are being held into the warm spring and summer months.
• 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, take immediate action.
Feel, smell or walk around the bin and probe the sunflower seeds; don’t just peer through a roof opening and assume there is no storage problem. It’s also a good idea to write down the results of each inspection for future reference.
• Act Quickly to Stabilize Problems — Should a problem be detected, try to stabilize it with aeration. If that fails, move the seeds to market immediately, as the problems will only increase.