Corn harvest is starting in numerous areas across Georgia. Dr. Mike Toews, UGA Assistant Dean of Extension, has provided a few points to think about on the subject of on farm storage.
Successful on-farm grain storage in Georgia requires starting clean, temperature and moisture control through aeration, storing grain at an appropriate moisture content, and use of a protectant if the grain will be stored for more than 6 months. Prior to filling, empty bins need to be swept or vacuumed and treated a few days before filling with a residual insecticide like Tempo SC or Centynal Synergized. Don’t forget to clean out and treat augers, driers, and false floors as these areas tend to hold insects year-round. Exterior premises should be maintained by sealing and draining water away from the facility, removing vegetation near the structure, and promptly cleaning up spilled grain.
Grain protectants, insecticides labeled for application to shelled grain, are intended to prevent stored grain insect infestations. Top performing protectants that are available for use on corn this year include Actellic 5E and Gravista. Sensat has performed well in tests but is being discontinued and new product is not available. Less expensive protectants like Centynal EC, Diacon IGR, and D-Fense SC simply provide shorter residual protection. Do not use malathion as it doesn’t perform well under Georgia conditions. When possible, grain protectants should be applied to cool grain that is of proper storage moisture with minimal dockage and fines. Apply protectants at the bottom of the auger so the insecticide can thoroughly coat the kernels as they are conveyed up the auger. Properly treated grain at the labelled rate is safe for human and animal consumption.
After the bin is full, make sure to level the grain surface and avoid any grain from touching the roof. Methods to level the grain include using a spreader during loading, manually leveling the peak with shovels or a board, or pulling a load out after the bin is full.
Stored grain insects and pathogens develop faster in warm and moist grain so reducing grain temperature and moisture with aeration is critical. The best way to manage grain temperature and moisture is to install a controller that operates the bin fan(s) when the air temperature is more than 10 degrees cooler than grain temperature. Grain stored for more than just a few weeks needs to be brought down to 14.5% moisture or less. While it is more efficient to pull air from the top and out the bottom than to push air from the bottom and out the top, but both methods can provide satisfactory results. Ideally, grain temperatures need to be reduced to 70 degrees in late summer, then 60 degrees when possible, and finally 40 degrees when cooler air is available in the fall.
Fumigation is the only remedy for active insect infestations in stored grain.
If you have questions please contact your local county Extension agent.