|YANG, YUBIN - Texas A&M Agrilife|
|WILSON, L. TED - Texas A&M Agrilife|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2010
Publication Date: 4/1/2011
Citation: Arthur, F.H., Yang, Y., Wilson, L. 2011. Use of a web-based model for aeration management in stored rough rice. Journal of Economic Entomology. 104(2):702-708. http:\\dx.doi.org/10.1603/EC10290.
Interpretive Summary: Expert systems utilizing population models and bin-cooling models are available for management of stored wheat and stored corn but not for stored rice. We developed a web-based system for management of the lesser grain borer and the rice weevil, two major economic pests of stored rough rice. This model was used to predict population growth of both species in unaerated rice and rice cooled at different airflow rates using aeration (blowing outside ambient air through the bin to cool the grain), for rice stored in Beaumont, TX. Predicted population growth of both species in aerated rice was about 98% less than in unaerated rice, regardless of starting grain temperatures or aeration airflow rate. This web-based system could help management programs for stored rice by increased use of aeration and potentially less usage of fumigants for insect control.
Technical Abstract: A web-based model was used to simulate the impact of aeration on population growth of the lesser grain borer, Rhyzopertha dominica (F.), and the rice weevil, Sitophilus oryzae (L.), in stored rough rice at Beaumont, TX, USA. Simulations were run for each of 10 years with 1 August as the start date, 31 December as the end date, beginning populations of 2.5 adults/metric ton (1,000 kg), starting grain temperatures of 29.4, 32.2, and 35.0°C, and aeration airflow rates of 0.27, 0.79, and 1.40 m3/min/metric ton of rice. In the absence of aeration, populations of both species increased exponentially, with maximum production of R. dominica and S. oryzae at starting grain temperatures of 35.0°C and 32.2°C, respectively. Final predicted populations of R. dominica on 31 December from grain starting temperatures of 29.4, 32.2, and 35.0°C were 5,465, 6,848 and 11,855/ton; final predicted populations of S. oryzae were 13,288, 21,252, and 4,355, respectively. In contrast, aeration led to a reduction in grain temperature and a decrease in pest populations, regardless of starting grain temperature or aeration airflow rates. Predicted populations of R. dominica on 31 December ranged from 12 to 63 adults/ton at all grain starting temperatures and airflow rates; populations of S. oryzae on 31 December ranged from 108 to 193/ton at all grain starting temperatures and airflow rates. The predicted population levels in aerated rice represented at least a 98% reduction compared to unaerated rice. Results show the utility of the web based model and how the various model inputs can help define broader patterns of insect control in rice stored in the south-central United States.