|Arthur, Franklin - Frank|
Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/14/2008
Publication Date: 8/1/2008
Citation: Arthur, F.H., Yang, Y., Wilson, L.T., Siebenmorgen, T.J. 2008. Feasibility of automatic aeration for insect pest management for rice stored in East Texas. Applied Engineering in Agriculture 24: 345-350. Interpretive Summary: Although many farm storage bins are equipped with aeration fans to cool the stored grains, in many cases the fans are simply activated manually and operated for variable time periods. We conducted a field test on rough rice stored in eastern Texas, a warm humid climate, and compared temperatures and insect development in bins with manual aeration versus aeration operated through an automatic controller. In the bins with automatic aeration, the temperature of the stored rice was immediately reduced compared to the bins in which manual aeration was used. This temperature reduction led to lower numbers of the lesser grain borer and the rice weevil, two common insect pests of stored rough rice. Results show the benefits of using automatic aeration to manage stored rough rice.
Technical Abstract: Aeration using automatic controllers was compared with manually-activated aeration (manual aeration) in bins of farm-stored rice in Nome, TX, from 17 September 2002 through the end of the year. Manual aeration was defined as the farm owner activating the fans manually in mid-October, while automatic aeration employed activation temperatures of 23.9, 15.6, and 7.2°C for three discreet cooling cycles. Population development of Rhyzopertha dominica (Fab.), the lesser grain borer, and Sitophilus oryzae (L.), the rice weevil, was assessed by confining 20 parental adults of each species with 150 g of rough rice in separate cages placed at 6 different locations in the top of the rice mass. Total heat units greater than 15°C were 150 to 300 degree days (DD) lower in bins with automatic aeration compared to manual aeration. Temperatures from 17 September through mid-October were 8-10°C cooler in bins with automatic aeration compared to manual aeration, and 3-6°C cooler during the remainder of the year. The number of adult R. dominica in the cages from bins with manual aeration were 45.4 ± 13.1, 114.5 ± 17.7, and 223.0 ± 24.8 after 5, 10, and 15 weeks, respectively, while populations in cages from bins with automatic aeration were significantly less (P <0 .05); 0.8 ± 0.3, 24.5 ± 4.5, and 21.7 ± 2.7 after 5, 10, and 15 weeks, respectively. There was no statistical difference (P greater than 0.05) in the number of adult S. oryzae collected in cages from bins with manual versus controlled aeration after 5 weeks (11.7 ± 8.1 and 0.3 ± 0.3, respectively), 10 weeks (14.7 ± 7.1 and 18.0 ± 9.6, respectively), and 15 weeks (39.0 ± 21.2 and 10.5 ± 5.6, respectively). However, the variation in the data set could have masked the apparent differences in the two aeration strategies. Results show the feasibility of using automatic aeration to manage stored rice in eastern Texas.