Grain farmers invest too much time, energy and money into producing their crops to allow insect pests to reduce volume and quality in on-farm storage facilities.

Farmers have good reasons to pay close attention to protecting stored grain, says Texas AgriLife Extension entomologist Roy Parker.

Managing grain in storage facilities allows a producer to “develop a reputation as the individual from which to purchase grain,” Parker said during the recent Texas Plant Protection Association annual conference in College Station.

“Insect management is one way to achieve that reputation, but it requires attention to all aspects of the stored grain operation,” he said.

Insect damage causes multiple problems including loss of yield through destroyed kernels, reduced quality from insect parts, increased heat (10 to 15 degrees higher), more moisture and mold, odor, additional dust and as much as  5 percent weight loss per year. All those issues may mean a 16 percent loss in market value in just one year.

IPM tactics

Parker recommends an integrated pest management  approach to controlling insects in stored grain. IPM tactics include:

  • Set harvest equipment to reduce trash, fines and broken kernels.
  • Harvest at a safe, low moisture level but not so low that grain cracks.
  • A storage moisture level of 13 percent to 14 percent is the highest level to allow (lower for certain grain types).
  • Practice sanitation and treatment of harvest equipment, grain carts, augers, transport trucks, rail cars, barges and ships. Sanitation should include: clean harvest equipment; clean hauling equipment; and clean pits, augers and conveyors
  • Immediate sanitation inside and outside storage.
  • Design construction for ease of cleaning and tight seal for effective fumigation. Note: construct storage bins so that a pressure can be held for an extended period when sealed for fumigation or have at least one bin for such use.
  • Treat empty bins with insecticide about two weeks before loading (Tempo, Storcide II, Silicon dioxide, malathion).
  • Apply insecticide to grain as it is loaded into storage after drying. Note: consider protectant use where grain will be stored under warm conditions for more than five months (Actellic + Diacon, Storcide II, and others).
  • Remove grain peak and “core” round bins.
  • Apply top-dress insecticide if not used on the rest of the grain.
  • Aerate to remove harvest heat followed by cooling to 60°F or less (40°F is best).
  • Monitor grain temperature to find “hot spots” (thermocouples).
  • Inspect grain for insects once a month when it is cool (less than 60°F) or twice a month (at more than 60°F).
  • Keep records of insect numbers by species (per unit volume), location in bin, grain moisture, grain temperature, and bushel weight.
  • As a general rule apply fumigant when one primary pest or five secondary pests per quart sample of grain are detected. Note: Higher numbers of some insects such as psocids and rusty grain beetle can be tolerated. Note: Wheat may need to be fumigated at one insect per quart sample.
  • Do not store “new” grain on top of “old” grain. If it must be done apply fumigant to “old” grain first.

He said producers should know the flow rate of the grain to assure proper insecticide application in-stream.

Parker said producers may choose from several products for grain stream treatment. Options include: Actellic for corn and grain sorghum; Storcide II for barley, oats, rice, sorghum and wheat; Diacon II, which is generally not used alone; and Contain. He said a label for spinosad may be on the horizon.

Fumigants include Phosphene gas and Profume.