The results of this project will have broad implications for all stored cereal grains, other postharvest bulk commodities (e.g., nuts), and all commercial facilities that process cereal grains, manufacture cereal products, and store or distribute value-added packaged food products. 1999) indicated that insects are managed primarily by chemical treatments, and IPM practices such as storage hygiene, aeration, grain turning, sampling and monitoring of grain for insects, temperature, and moisture are under-utilized, resulting in poor insect control and deterioration of grain due to insects and molds.

    The level of IPM and pesticide use in stored wheat varies among the U.S. wheat-growing regions (Kenkel et al. 1992, Martin et al. 1997). This is related to the environmental conditions existing in these various regions, different insect species associated with wheat in different wheat-growing regions, susceptibility of different wheat classes to insects and time wheat is in storage.

    No one crop can be isolated and described with regard to acreage affected. Stored grain is described by volume, in bushels, and thus we need to estimate what percentage of these stored bushels might be treated with OP grain protectants in a year. For example, the typical U.S. harvest for hard red winter wheat (HRWW), the raw commodity used for production of flour for bread baking, is about 1.2 billion bushels annually and about 900 million bushels of that is stored at commercial grain elevators for 1 or more months. A 1992 survey of pest management practices at 1020 HRWW grain elevators in the U.S. (Kenkel et al. 1992) found that OP grain protectants were used predominantly on wheat stored in large steel bins (which are difficult to fumigate), representing about 40% of the stored crop, or 360 million bushels. Of elevator managers surveyed, 30% reported treating grain in steel bins with malathion while 23% reported using chlorpyrifos methyl. Thus, about 190 million bushels of HRWW (produced on about 4.7 million acres of land) was treated with OP insecticides directly. This figure represents about 15% of the entire HRWW harvest for that year. This 15% value for amount of crop treated may be conservative. A 1996 survey of IPM practices for northern U.S. and Canadian stored wheat (Martin et al. 1997) reported that 48.5% of farmers and 45% of elevators in the U.S. used OP grain protectants, primarily malathion and chlorpyrifos-methyl, on stored wheat. Assuming that 15% of other stored grains (e.g. corn, rice, oats, barley, etc.) are typically treated with OP grain protectants, a significant proportion of stored commodities will be left untreated if these labels are cancelled.

    The NASS survey (NASS 1999) of elevator managers indicated that 11.6% of wheat stored at the elevators was fumigated with phosphine, 1.4% was treated with chlorpyrifosmethyl, and 1.5% with malathion. Assuming a cost of $ 2.50/bushel of wheat and a cost of 1 cent/bushel each for phosphine and malathion treatment, and 2 cents/bushel for chlorpyrifosmethyl treatment, the total annual estimated costs of pesticides used on wheat would be $5.7 million. These costs do not include costs of pesticides applied to empty bins, costs of pesticides used on farm-stored wheat, costs of aeration/sanitation, labor costs, costs associated with resistant development in insects, quantitative and qualitative losses of grain due to insect infestation, and discounts applied for delivering insect-infested grain at the time of sale.