|Throne, James - Jim|
Submitted to: Journal of Stored Products Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/19/2001
Publication Date: 2/15/2003
Citation: THRONE,J.E., DOEHLERT,D.C., MCMULLEN,M.S. 2003. SUSCEPTIBILITY OF COMMERCIAL OAT CULTIVARS TO STORAGE INSECT PESTS. JOURNAL OF STORED PRODUCTS RESEARCH 39:213-223. Interpretive Summary: Oats are susceptible to insect pests during storage. We investigated susceptibility of eight commercial cultivars of oats grown in the U.S. to flat grain beetles and sawtoothed grain beetles, two common insect pests of stored oats in the U.S. Whole oats could be stored at high temperatures for at least a year without reaching the damage threshold. The damage threshold was reached in about three months when oats were cracked. The results indicate that no insect control would be required if oats were cleaned before storage.
Technical Abstract: Susceptibility to two storage insect pests (Cryptolestes pusillus and Oryzaephilus surinamensis) of eight commercial oat cultivars was determined in laboratory studies. Duration of development was shorter and number of progeny produced was greater on cracked than on whole oats. Predictions based on data from the laboratory study showed that insect populations would reach the threshold level for treatment in two to three months of storage at 30 degrees C on cracked oats. Insect population development was slowest on the hulless cultivar Paul when the oat kernels were cracked. Predictions also showed that all whole oats could be stored for at least one year at 30 degrees C without reaching the threshold for treatment, and insect populations would decrease over time on the cultivars Don, Jerry, Milton, NewDak, Otana, and Valley. Analysis of oat grain quality characteristics provided little insight into the mechanism of observed differences in insect development among cultivars. Hardness of the kernels (as indicated by % broken groats after dehulling) may be related to near immunity to these insects in whole Otana. Steaming whole oats to inactivate hydrolytic enzymes in the trichomes of the pericarp did not increase susceptibility to these insects, suggesting that enzymes in the trichomes were not responsible for slower population development on whole oats than on cracked oats. Although we were unable to identify the factors that determined relative susceptibility in this study, the results will be useful for selecting commercial oat cultivars for planting that will be less susceptible to insect pests in storage and suggest that the economics of cleaning oats before storage to reduce insect population growth should be investigated.