Control Of Insects In Stored Grains Research Articles

Controlling insects in stored grain by disturbing the grain: Presentation

Insects can cause damage to stored grain, especially on smallholder farms in the tropics. Sitophilus zeamais (maize weevil, MW) and Rhyzopertha dominica (lesser grain borer, LGB) are often involved. Our objective was to determine, by four experiments, if physical disturbance of grain can control these pests. In Experiment 1, 2.6-L unsealed recycled coffee cans were each loaded with 1 kg of maize and 25 live adult MW/kg. Every 12 h, disturbed treatment cans were manually rolled through one circumference. After 160 d, live MW numbers had been reduced by 93% compared to undisturbed cans. In Experiment 2, MW-infested maize was placed in 20-L plastic cans and stored by farmers in Tanzania. Each farmer had three cans. Two were disturbed by shaking morning and evening and the third was left undisturbed. After 90 d, MW populations had increased in the undisturbed containers, but had decreased to zero in every disturbed container. In Experiments 3 (and 4), maize (wheat) infested with 25 adult MW/kg (LGB/kg) was placed in six boxes. Three of the boxes were disturbed every 12 h by use of Sukup motor-driven grain stirrers; the other three were undisturbed. After 120 days, MW numbers in undisturbed boxes had increased, but were zero in stirred boxes. In Experiment 4, 80-d samples showed increased numbers of LGB in undisturbed boxes but reductions of over 98% in stirred boxes. Quality of disturbed grain was similar or better than that of undisturbed grain. This work suggests that grain disturbance may be an effective non-chemical, non-hermetic physical approach for control of stored grain insects.

Simulation of phosphine flow in vertical grain storage: a preliminary numerical study

To fumigate grain stored in a silo, phosphine gas is distributed by a combination of diffusion and fan-forced advection. This initial study of the problem mainly focuses on the advection, numerically modelled as fluid flow in a porous medium. We find satisfactory agreement between the flow predictions of two Computational Fluid Dynamics packages, Comsol and Fluent. The flow predictions demonstrate that the highest velocity ($>0.1$\,m/s) occurs less than $0.2$\,m from the inlet and reduces drastically over one metre of silo height, with the flow elsewhere less than $0.002$\,m/s or $1$\% of the velocity injection. The flow predictions are examined to identify silo regions where phosphine dosage levels are likely to be too low for effective grain fumigation. References K. Bullen, Insect control in stored grain, Technical report , DPIandF, Plant Science, Toowoomba, Queensland, 2007. http://www.dpi.qld.gov.au/26_6263.htm J. Canchun, D. W. Sun, and C. Cao, Computer simulation of temperature changes in a wheat storage bin, Journal of Stored Products Research , 37 , 165--177, 2001. doi:10.1016/S0022-474X(00)00017-5 P. J. Collins, G. J. Daglish, M. K. Nayak, P. R. Ebert, D. Schlipalius, W. Chen, H. Pavic, T. M. Lambkin, R. Kopittke, and B. W. Bridgeman, Combating resistance to phosphine in Australia, Proc. Int. Conf. Controlled Atmosphere and Fumigation in Stored Products , Executive Printing Services, 593--607, 2001. http://www.ftic.info/CAFSITE/CAFPDF/60.pdf Comsol (2008). Comsol multiphysics user's guide. http://www.comsol.com P. W. Flinn and C. Reed, Effects of outside air temperature on movement of phosphine gas in concrete elevator bins, Proceedings of the International Conference on Controlled Atmosphere and Fumigation in Stored Products , 704--706, 2008. Fluent, Ansys inc. http://www.ansys.com A. K. Singh and G. R. Thorpe, A solution procedure for three-dimensional free convective flow in peaked bulks of grain, Journal of Stored Products Research , 29 , 221--235, 1993. doi:10.1016/0022-474X(93)90004-N E. A. Smith, D. S. Jayas, and A. D. Ville, Modelling the flow of carbon dioxide through beds of cereal grains, Transport in Porous Media , 44 , 123--144, 2001. doi:10.1023/A:1010760508392 E. A. Smith and D. S. Jayas, Modeling the movement of fumigant gas within grain beds, American Society of Agricultural Engineers , 44(3) , 661--667, 2001. http://asae.frymulti.com S. Xu, D. S. Jayas, N. D. G. White, and W. E. Muir, Momentum-diffusive model for gas transfer in granular media, Journal of Stored Products Research , 38 , 455--462, 2002. doi:10.1016/S0022-474X(01)00048-0

Flameless catalytic infrared radiation used for grain disinfestation does not affect hard red winter wheat quality

The effects of a bench top flameless catalytic infrared emitter at temperatures and times used for disinfesting grain on the physical, chemical, rheological, and end-use qualities of wheat were evaluated in the laboratory. The test weight of wheat was unaffected when 113.5 and 227.0 g of hard red winter wheat were exposed for 45 or 60 s to infrared radiation. However, a slight drop in kernel moisture increased kernel hardness, but these effects were reversed when the wheat was tempered prior to milling. Flour, shorts, and bran yields, and chemical properties (protein and ash) of these fractions from untreated wheat and infrared-treated wheat showed minor differences that were inconsequential. Mixograph and bake test results did not reveal any consistent adverse effects of infrared radiation on the quality parameters studied. Our results show that infrared treatments that provide effective control of stored-grain insects do not affect the physical, chemical, rheological, and end-use qualities of hard red winter wheat.

Mortality and Progeny Production of Several Stored Grain Beetle Pests in Shelled Corn Treated with Entrust®

ABSTRACT Use of synthetic chemicals has been the primary method of insect control in stored grain. Concern for insecticide resistance, chemical residues, environmental contamination, and worker exposure has lead to development of biologically based insecticides such as Spintor® 2SC. Spintor has been found to be effective against several stored grain beetle species on wheat and shelled corn in storage. Recently it was re-formulated to conform to OMRI national standards and is now commercially available as an organic insecticide (i.e., Entrust®) registered for use on fruits and vegetables. However, no information regarding the use of Entrust on stored grains has been found. A laboratory study was conducted to determine efficacy of Entrust on maize weevil (Sitophilus zeamais Motsculsky), red flour beetle (Tribolium castaneum (Herbst)), and sawtoothed grain beetle (Oryzaephilus surinamensis (Linnaeus)) infesting stored shelled corn. Shelled corn was treated with 1 ppm or 3 ppm of Entrust or left untreated. Mo...

Aeration of Rough Rice in Long-Term Storage

ABSTRACT RESEARCH on long-term storage of rough rice was performed to determine the effectiveness and limitations of aeration for maintaining the quality of rice in bulk storage in the warm and humid climate of the Texas rice growing area. Control of stored-grain insects was determined to be the most important consideration in successful long-term storage of rough rice. Rice in bins equipped with aeration was maintained at cooler temperatures than was rice in non-aerated bins. With aeration, rice was cooled to temperatures of 15 C (59 F) or lower throughout late fall and winter months to greatly inhibit insect reproduction. Cooler average rice temperatures in aerated bins compared with rice temperatures in non-aerated bins, kept germination of seed at a higher level, and slowed the buildup of fat acidity. Rice stored 54 months in bins in which insect infestation were controlled remained at grade, U.S. no. 1, and was more than marginally acceptable to the majority of taste panel participants.