Stored grain, as with other durable stored commodities and their value-added products, are at their highest quality just after harvest or manufacturing, and are at risk of decreased quality during storage from the depredations of insects, molds, vertebrate pests and physical damage. A new technical training book produced by Kansas State University, Stored Product Protection, details the types of pests and damaging agents, methods for management, prevention of infestation, control, the economics and regulatory issues associated with changes in grain quality, and the practice of pest management.
Stored Product Protection is written for individuals involved with grain storage, commodity storage and management, food processing and pest management. Its target audience also includes academic, government and private sector researchers in these fields, and regulatory personnel. Though the book focuses on North America, examples are drawn from stored product experiences in many parts of the world. Comprised of 31 chapters written by experts in the field, the book covers three general topic areas:
- The biology and ecology of insects, molds and vertebrates in storage systems;
- Insect pests of cereal grains and legumes, dried fruits and nuts, and processed and durable commodities of both plant and animal origins; and,
- The various aspects of pest management, i.e., prevention methods, monitoring-based methods, decision making, economics, regulations and marketing.
The points made in the book are important for anyone involved in storing, protecting and marketing high-quality grain and grain products. The following is a brief overview of the most significant findings the book explores.
The economics of pest control
Understanding pest biology is important because pest management is applied ecology. Some insect species can directly damage sound grain kernels causing immediate quality and value loss (Fig. 1), while numerous other species feed on grain dust, broken kernels and associated fungi and thus contribute to the level of infestation and filth that can lower the grade of grain (Fig. 2). Many methods are available for managing pests, and each can be used in a variety of ways.
Insects can readily develop resistance to chemical control methods so resistance management programs should be part of all pest management programs. Commodity manager’s choices of the best control method, and the best time and the best way of using that method, can be complex. Properly timed pest management may require a number of monitoring programs. Due to the complexity of various storage systems, extension agents and private consultants might often play a role in developing integrated pest management programs for stored products. Such decisions require cost-benefit analysis, so an understanding of economics is important.
Timely cost-benefit analyses are important for any company, and for the feed and grain industries such economic analyses must consider the cost of preventing or mitigating pest problems for the benefit of delivering a high-quality product vs. the savings of doing no pest management but having reduced profit from a lower quality product or loss of product. For example, if a grain elevator does not practice proper monitoring and pest management, and sells grain that is found upon inspection to have two or more live insects injurious to grain in a sample, the merchant may have to pay a dockage or fumigation fee of up to $0.50/bushel on the entire shipment. Alternatively, if that same grain company had found the live insects before shipping and spent $0.04/bushel to fumigate in-house, then a significant cost would have been avoided. In a study of grain elevators that provided grain to the breakfast cereal industry (http://storedproducts.okstate.edu/Publications/OSU-Elevator-IPM.pdf), we found that the cost of pest management varied widely among elevators as a function of structure age or design, but in all cases the tangible benefits realized from IPM were clearly the avoidance of costs that might occur with insect infestation and the resulting loss of grain quality.