Pests can degrade grain quality by damaging kernels, introducing moisture, contamination and causing bad odors. Proper aeration will, of course, help prevent pests from getting out of hand, but in case one should find themselves with an insect, rodent or bird problem, pest control methods are available to address the unwanted invaders.
Jerry Heath, product manager and staff entomologist at Industrial Fumigant Company, explains how closely intertwined proper aeration is with pest control. “Insects thrive in moisture and heat, so cooling grain through aeration is one of the first steps in avoiding a problem. Keeping the grain cool doesn’t kill any insects but holds the population at a status quo rather than continuing their growth,” Heath says. Chant agrees and attests that insects begin to cause problems in environments above 56 F.
Industrial Fumigant Company uses a pyramid model (on pg. 28) to demonstrate the steps in properly addressing a pest control problem. First, understanding your pest threats will aid in preventing problems. “Identify your pests and understand their biology. You can attack them at a vulnerable stage if you know their life cycle or specific needs, or you can minimize attractant factors,” Heath says. Some common pests include the lesser grain borer, maize and rice weevils, Indian meal moth and a number of others.
Next, a sanitation program should be designed to keep the most critical areas clean, deny harborage and disrupt the pest’s life cycle. A good sanitation program begins with clean bins. Heath finds that damaged kernels and foreign material tends to concentrate in a central column or core. Some bin designs make it easy to unload these bad cores, leaving behind the best quality grain.
Diligent inspection and monitoring are additional tactics. Heath comments that a simple, overlooked tool can be an inspector’s best friend: a flashlight. Trapping is a standard technique for certain pests, but other physical controls are sometimes necessary, such as the use of exclusion screens, or improving doors, windows and many other facility design features.
“Pesticide use should be a relatively small part of the big picture, but an important capstone on the pyramid. Sanitation, inspection and monitoring, good housekeeping and facility maintenance will all help simplify or minimize pesticide use. Proactive use of grain protectants, for example, is becoming more cost- effective and appealing than reacting to infestations with fumigation,” says Heath.
The last piece in the grain quality puzzle is proper diagnostics. Harmful mycotoxins, such as aflatoxin, can affect whether or not a commodity is marketable. The Food and Drug Administration (FDA) has established action levels for aflatoxin present in food or feed, and grain possessing levels higher than indicated are prohibited from selling.
According to the United States Department of Agriculture (USDA), aflatoxin can become a problem at temperatures of 80 to 90 F, but can survive in environments as low 40 F. The mold thrives in hosts containing high levels of moisture.
Any and all of the above mentioned measures (moisture management, aeration, temperature, pest control) can contribute to high toxicity levels. Dean Layton, vice president marketing and sales of EnviroLogix, says “Stressful conditions at critical stages in the crop’s growth can make it vulnerable to the fungi that produce mycotoxins. Improper storage conditions can also promote mold and fungi growth and thus the mycotoxins they produce. Proper drying of grain soon after harvest and maintaining relatively dry and well ventilated storage conditions with adequate pest control are important in the prevention of mycotoxins.”
Layton suggests taking multiple samples to ensure maximum grain quality of each truckload. “Since mycotoxins are not generally distributed evenly throughout the bulk grain sample, it is important to take multiple sub-samples to ensure representative sampling and accurate detection.”
Quickly taking a sample of grain and determining its toxicity level is crucial in maintaining high-quality grain. The speed of the test affects grain quality because quick test times allow the trucks to remain in queue, thus allowing the grain receiving locations to avoid contaminating clean bins with a truck load that does not meet acceptable levels.