|Takahashi, Kenichi - NAT FOOD RES INST, JAPAN|
|Soto, Nahoto - NAT FOOD RES INST, JAPAN|
Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 27, 2002
Publication Date: June 15, 2003
Citation: ARTHUR, F.H., TAKAHASHI, K., SOTO, N., HOERNEMANN, C.K. POTENTIAL FOR AUTUMN AERATION OF STORED ROUGH RICE AND THE POTENTIAL NUMBER OF GENERATIONS OF SITOPHILUS ZEAMAIS MOTSCHULSKY IN MILLED RICE IN JAPAN. JOURNAL OF STORED PRODUCTS RESEARCH 39: 471-487. 2003. Interpretive Summary: In Japan rice is stored as rough rice in bins and silos or as bagged milled rice in cold storage. During summer milled rice can be removed from storage and stored at ambient conditions, where it is vulnerable to insect pests. Aeration with low-volume ambient air is not part of most programs in Japan for managing insects in stored rough rice, and background information and data are needed to determine if this strategy would be appropriate for Japan. We used historical weather data to classify the country of Japan into different regions, and showed that weather conditions would allow the use of aeration throughout much of the country to cool rough rice stored in the fall. In addition, several generations of insects could be completed during the summer if milled rice is removed from cold storage and becomes infested at ambient conditions. These simulation studies show how historical weather data can be used to develop risk management models for stored rough rice and for bagged milled rice in Japan.
Technical Abstract: Historical weather data from 84 sites in Japan were used to estimate the number of hours at or below 15 degrees C. from 1 September to 31 October, in order to evaluate the potential for using aeration at a threshold level of 15 degrees C. to cool rough rice stored during autumn. Data from the temperature analysis were used to arbitrarily divide Japan into 10 climatic zones, one site was chosen to represent each zone, and an estimated date of storage was assigned to each site. At an airflow rate of 0.0013 m3/s/m3, the time required to cool a storage silo containing rough rice to 15 degrees C. ranged from 85 days in southern Japan to 5 days in northern Japan. Historical weather data for the same sites were also used to estimate the average number of hours below 15 degrees C. from 1 May to 30 October, so as to evaluate the potential of Sitophilus oryzae (L.), the rice weevil and Sitophilus zeamais (Motschulsky), the maize weevil to infest bagged milled rice at ambient or uncontrolled temperatures. At each station, there is a decrease in the number of days required to complete a generation, and a corresponding increase in the predicted number of generations as relative humidity increased. In addition, with each successive increase in relative humidity, the predicted number of generations generally increased with the northward progression of the temperature zones.