|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: Wilson, J.P., Wilson, D.M., Jurjevic, Z. 2006. Equilibrium moisture content of pearl millet. International Sorghum and Millets Newsletter 47:120-122.
Interpretive Summary: Pearl millet cultivation for grain is increasing in the southern United States. This new end-use is finding outlets in the livestock (primarily poultry) and recreational wildlife industries. Future use of the grain as an ethanol feedstock is likely. Demand for high quality product requires information on practices to preserve this new agricultural product. The information derived from this study of the interaction of relative humidity with grain moisture content and mold development provides a decision-making support tool for farmers and grain brokers involved in this new industry.
Technical Abstract: Moisture content has a significant influence in the storability of cereal grains. The relationship of temperature, relative humidity, and equilibrium moisture can indicate the need for drying grain to improve storability and prevent grain mold development. This information is available for many grains, but not for pearl millet. The objective of these experiments was to determine the moisture sorption properties of three pearl millet varieties at 25oC. Experiment, relative humidity, and genotype had significant effects (P<0.0001) on grain moisture. Desorption and adsorption isotherms exhibited a typical hysteresis effect in that the equilibrium moisture content was greater for the desorption process compared to the adsorption process at higher relative humidities. Genotype differences were most evident at 100% relative humidity. A large seed genotype consistently absorbed more moisture compared to HGM 100 and Tifgrain 102. Mold development was visually greater on the large seed variety after 5 weeks of incubation in experiment A, particularly at the 79 to 80.7% relative humidity treatments. The isotherms are relevant to determining safe storage conditions of pearl millet. Data indicate that at 25oC, maintaining grain moisture below 14% is sufficient to prevent storage molds.