The major achievements of grain storage in P. R. China

Abstract

During the past several decades, China has made great progress in grain storage research, which greatly improved and promoted grain storage techniques and facilities. Especially in the 1990s, modern grain storage depots were constructed, in which four new technologies of grain inspection automation, machinery aeration, grain cooling, and phosphine recirculating fumigation were popularized. The main technologies to phase out methyl bromide in national depots are under-film phosphine recirculation fumigation and mixing fumigation of phosphine and carbon dioxide. In grain storage scientific research, research programs from applied to molecular fields have been implemented in institutes and universities. The 4th national survey of stored grain insects showed 270 species including 44 natural enemies were recorded. Among these stored grain insect pests the psocid, Liposcelis bostrychophila is generally more prevalent in stored grain with high moisture content. Hence, bionomics, ecologies, control measures, and molecular biology have being conducted since 1990s, and many achievements have been obtained. Efficacy of new grain protectants such as diatomaceous earth and spinosad against the main stored grain insects were evaluated. Researches on effective concentration of phosphine, application technique, recirculation fumigation, combination phosphine with carbon dioxide, and phosphine resistance mechanism were executed. Other fumigants tested included ethyl formate, carbon disulfide, and sulfuryl fluoride against stored grain insects were evaluated, or reevaluated. The fumigation activities and mechanisms of ethyl formate to the main stored product insects were systemically studied and the results showed ethyl formate controlled Sitophilus oryzae, Tribolium castaneum, Rhyzopertha dominica and Liposcelis bostrychophila effectively in a very short time, and the fumigation efficacy at relatively low temperature was better than that at relatively higher temperature. With the rapid progress of technology and scientific research, the objectives of high quality, high nutrition, high benefit, low waste, low pollution, and low cost in grain storage will be achieved, even during prolonged storage.

Keywords: Review, Grain storage, Insect pest control, Fumigants, Psocids