Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2006
Publication Date: 5/1/2006
Citation: Butts, C.L., Dorner, J.W., Brown, S.L., Arthur, F.H. 2006. Aerating farmer stock peanut storage in the southeastern u.s.. Transactions of the ASAE. 49(2):457-465.
Interpretive Summary: After peanuts are delivered by the grower to the buying facility, they must be stored in-shell in large bulk storage facilities. To minimize losses due to excessive mold growth or over drying, the space above the peanuts must be ventilated or air forced through the mass of peanuts. This process of ventilating the headspace and/or aerating the peanut pile exhausts excess moisture from the peanuts as they continue to dry and cools the peanuts. This study was conducted to determine the proper airflow rate for aerating these farmer stock peanuts. When the peanuts were aerated at a rate of three cubic feet per minute/ton of peanuts using a single tunnel and headspace ventilation, peanuts were cooled more rapidly than using headspace ventilation alone. Based on this research, recommendations for controlling the environment within a farmer stock peanut warehouse includes: 1. Change the air in the space above the peanuts once every two minutes 2. Force air at the rate of three cubic feet per minute/ton of peanuts up through a single duct down the middle of the warehouse and change the air in the space above the peanuts as in 1. 3. Force air through the peanuts at a rate of ten cubic feet per minute/ton of peanuts with no ventilation of the space above the peanuts.
Technical Abstract: A two-year study was conducted to determine acceptable aeration strategies for farmer stock peanuts stored in conventional warehouses with and without headspace ventilation. Farmer stock peanuts were stored in 1/10th scale model warehouses with various aeration and ventilation treatments. Peanuts were loaded into each warehouse in the fall and stored for about 190d. Peanuts stored with aeration, generally cooled faster than those stored without aeration. While storing peanuts from the 2002 crop, aflatoxin increased significantly in the warehouse without aeration. However, aflatoxin contamination was not a factor in the 2003 storage season. Value change based on kernel size distribution was not significantly affected by aeration. Aeration minimized the production of aflatoxin in the year that aflatoxin was detected in the initial samples. An aeration rate of 0.31 m3min-1t-1 was sufficient for proper aeration when used without headspace ventilation. The reduced aeration rate of 0.10 m3min-1t-1 in conjunction with headspace ventilation cooled the center of the peanut mass sufficiently to reduce the risk of aflatoxin production in storage. Headspace ventilation with the aeration reduced the temperature difference between the top and bottom layers of peanut during storage. Based on this research, farmer stock peanut storage may be aerated successfully with 0.10 m3min-1t-1 through a single delivery duct in conjunction with conventional headspace ventilation. Cost efficiency among headspace ventilation only, headspace ventilation with reduced rate of aeration, or full rate aeration, must be determined based on warehouse configuration and loading.