Experimental study of the CO₂ controlled atmosphere for controlling stored-grain insect

By using the experiment equipments designed and manufactured by us, the CO₂ gas was charged to suffocate and kill the grain insects(Rhizoptha Dominica Fabricius and Sitophilus Oryzae Linnaeu), to protect the grain. The experiments are devided into two parts, first part was done in the laboratory and the temperature was 15～18℃ and 23～28℃; The CO₂ gas density was about 25%, 30%, 35%, 40%, 45%, 50%, 55% and 60%, respectively. The time was 24, 48, 72, 96, 120, 168 h, respectively. After repeated experiments, the optimum parameters were found: the temperature in the grain warehouse was(25±3)℃; The CO₂ gas density was 25%～35%, Rhizoptha Dominica Fabricius will be dead in 72 h and Sitophilus Oryzae Linnaeu will be dead in 48 h. Second part was done in the warehouse. The temperature sensors and the humidity sensors were put in the bottom, middle and top of the warehouse and the data were collected every 12～24 h. The results showed that the parameters got in the laboratory were correct. The best time for killing the insects was about 10 days. It established the technical base for controlling stored-grain insects by the CO₂ controlled atmosphere.