|Wilson, Jeffrey - Jeff|
Submitted to: International Sorghum and Millets Newsletter
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2006
Publication Date: 12/20/2006
Citation: Maw, B.W., Wilson, J.P., Sumner, P.E., Hanna, W.W. 2006. Drying properties of pearl millet grain for long-term storage. International Sorghum and Millets Newsletter 47:165-166.
Interpretive Summary: Pearl millet cultivation for grain is increasing in the southern United States. This new specialty-use product is finding outlets in the recreational wildlife and the livestock (primarily poultry) industries. Market development requires information on practices to most economically preserve the quality of this new agricultural product. This study provides specific information on drying practices that are being used by growers to prepare the grain for safe, long-term storage without spoilage by grain molds and insects. This information provides a decision-making support tool for farmers and grain brokers participating in this new industry.
Technical Abstract: Pearl millet (Pennisetum glaucum [L.] R.Br.) can be grown in difficult production environments characterized by sandy dryland soils with low fertility. Prior to storage in bins it is frequently necessary to dry the grain to levels that restrict the growth of molds and insects. Growers in the southeast are drying the grain with readily-available peanut wagons and dryers, but specific recommendations for this practice are not available. The objectives of this study were to characterize the drying properties and determine the time required to dry pearl millet. Pearl millet TifGrain 102 was placed at 30, 60, 90, and 120 cm deep in four drying chambers having perforated floors. Air heated to 37 0C was blown through the grain. Temperature and relative humidity of the drying air was recorded hourly, and grain moisture was measured twice daily. Changes in grain moisture with time were determined by polynomial regressions. Airflow readings diminished with increasing grain depth. Movement of the drying front could be measured by changes in temperature and relative humidity. The relative humidity of air above the grain followed an inverse relationship to the temperatures. The drying front passed through the 120 cm deep grain in just over two days. Moisture content tended to stabilize at about 9% moisture within 12 hours after the drying front passed. Grain at all depths had less than 12% moisture by the second day of drying. When drying small quantities of grain at 15 to 16% moisture, it is likely that 24 hours of drying followed by thorough mixing will allow the grain to equilibrate at levels safe for storage.