SBIR-STTR Award

The effectiveness of a self-shielded, low energy(<300 keV) electron processor for disinfection of stored products conveyed on a fluidized bed has been demonstrated, primarily for species, leafy herbs, and animal feeds. The process has been scaled up to a 4 kW industrial grade pilot capable of processing 1 ton per hour at 10 kGy. This system is now in use for the processing of spices. The low dose disinfestation application of the process will be studied for stored grains using the lesser grain borer and rice weevil as internal-feeders of wheat, and maize weevil as an internal-feeder of corn. This technique will also be used for evaluating the process against the sawtoothed grain beetle, an external-feeder of wheat. Mortality for the different life stages of these pests will be established at different doses by varying the electron beam current for a standard flow rate of grain. The effects of high velocity transportation of mortality of non-irradiated controls will be determined. The electron beam/fluidized bed technique can provide control of insect pests of stored grains with no residues, eliminating the problem intrinsic to insecticide treatments.

Anticipated Results/Potential Commercial Applications of Research:
:Lethality data for stored grain insect pests will be accumulated for both external feeders in wheat, and internal feeders in wheat and corn. This information will assess the efficacy of a new type of low energy electron treatment system in which the product is presented to the beam in pneumatic transport (i.e., fluidized bed). Application as an alternate/substitute process to the chemical fumigants and pesticides used for grain treatment will be determined.

Phase I studies have been successfully conducted to demonstrate the effectiveness of the low energy (<300 keV) electron beam fluidized bed process for the disinfestation of winter wheat infested with the four life stages of the rice weevil (S. oryzae), the red flour beetle (T. castaneum) and the lesser grain borer (R. dominica). The mortality studies will now be conducted in detail over the full life cycles of S. oryzae and R. dominica, the two internal feeders which are much less affected by protectants such as malathion and have a measure of protection from external agents due to their stages of internal feeding within the grain kernel. These investigations will be supplemented by fertility studies of the emergent adults at the two dose levels selected (200 and 800 Grays). These data will be used for simulation studies at the USGMRL, Manhattan, Kansas, in order to assess the efficacy of this process under a variety of multiple species populations and life stages. During Phase I, the mortality of three of the S. oryzae, larval instars was studied as a function of electron energy and dose, and these results will be used to guide similar studies in Phase II. Economic considerations of the process (for wheat) will be conducted based upon the optimum dose: energy protocol established by the study.

Anticipated Results/Potential Commercial Applications of Research:
This work will be continued with the internal feeding stages of both insects in wheat. This understanding of the lethality of the process and its impact on progeny (fertility) will permit a more accurate simulation of insect population behavior in ebfb treated wheat and other agroproducts. An assessment can then be made of the efficacy of this physical process for replacement of chemical fumigants and protectants used in the stored products industries. This must be accompanied by a complete economic analysis of the process at sites offering commercial levels for treatment, i.e. 10-100 tons.h-1. This work continues to be conducted below the 1000 Gray limit already established in 21CFR179.26