"Application of a protectant will provide a measure of residual control," says Arthur. "They are also easy to use. You simply hook up a sprayer to the grain truck, calibrate your flow rate and spray the grain with the treatment as it goes into the bin."
Choosing to use a grain protectant can potentially save money in the long run, according to Arthur. "Using a protectant is a valid method if you know you don't want to fumigate or if it would be cost-prohibitive for the company." If fumigation is not an economical option, then the grain protectant, in combination with aeration and cool temperatures, is a viable option."
The risk of pest infestation increases with higher levels of moisture, so it is crucial to dry the grain before storage. After it's been dried to the appropriate level, proper aeration helps keep it at the right moisture level and temperature.
"Aeration uses low-volume ambient air to modify the internal temperature of the grain so it's less conducive to insect development," Arthur explains. "As you lower the temperature and the moisture content, there's less of a chance for infestation. Once the temperature reaches below 60 F, most stored product insects cannot complete their life cycle."
VanGundy also suggests managing vegetation as part of a good IPM program. The absence of vegetation around the outside of the bin decreases the likelihood of an infestation. "Laying down a piece of plastic and then pouring a 20-foot-wide gravel bed around the bin should help keep vegetation to a minimum," says VanGundy.
Taking preventive measures, such as applying a grain protectant, aerating the bin and managing vegetation are all parts of an effective IPM. However, even after taking such precautions, fumigation is sometimes necessary to preserve the integrity of the grain. If a bin is highly infested, particularly with primary grain pests which live inside the grain, the only thing that can be done is fumigation.
The Montreal Protocol, an international treaty designed to protect the ozone layer by phasing out substances that are responsible for ozone depletion, has reduced the use of methyl bromide. Although this fumigant was not extensively used on bulk grain in the United States, it still represents the loss of a potential treatment. Phosphine is the fumigant of choice for the grain industry, and comes in numerous solid formulations of aluminum phosphide and magnesium phosphide, and cylinderized as a gas. They don't deplete the ozone layer, but still are very toxic to humans, according to VanGundy.
There is a new fumigant option, however, which does not deplete the ozone. ProFume®, from Dow AgroSciences (active ingredient sulfuryl fluoride) is a fumigant currently used in grain bins, flour mills and food processing facilities to control post-harvest pests. Most importantly, its production is not regulated or prohibited by the Montreal Protocol.
Advantages to using sulfuryl fluoride over metal phosphides for fumigation include shorter exposure times to meet shipping needs; it can be used to manage phosphine-resistant insects and, when used properly, it will not damage sensitive electronics such as bin monitors and, there are no particulate residues that warrant deactivation and disposal after fumigation.
Quality In Transit
The main objective of preserving grain quality is ultimately to ensure customer satisfaction. Maintaining grain quality post-harvest requires the handler to employ a host of best practices, including keeping it free of mold and pests during storage. But there's still one step before the grain makes it to the customer. Whether going overseas, or simply across state lines, grain quality must be maintained while in transit.
Paul Hammes, vice president and general manager for agricultural products of Union Pacific, says his company does everything it can to ensure that quality is maintained while traveling UP rail routes, but the responsibility also rests on the shipper.
"Our role is to ensure that the railcars we supply are in proper condition and the gates and hatches are in good repair," says Hammes. "There is a shared responsibility because the customer loads it with whatever quality grain they've got, but we supply the equipment, and we have guidelines on how cars should be sealed if they want to maintain some integrity in quality."