Effects of Storage Environment on Farmers Stock Peanut Grade Factors in an Aerated Warehouse in West Texas

Abstract

Abstract Temperature and relative humidity (RH) in an aerated warehouse in west Texas were monitored during storage of 1994 and 1995 crop farmer stock (FS) peanuts. Temperature and RH were measured at various positions throughout a vertical cross section of the peanut mass in the overspace and outside the warehouse. Data were collected at 1-hr intervals throughout storage. Peanut mass temperatures averaged 9.6 C during storage for the 1994 crop and 10.3 C for the 1995 crop. Relative humidity for the 1994 crop storage averaged 68.3 and 57.9% for the 1995 crop storage. Farmer stock grades were collected at warehouse loading and unloading for 10- to 12-t lots of peanuts stored in the warehouse (Wpnuts) and for samples (Spnuts) positioned at temperature and RH sensor locations. Wpnuts, in approaching equilibrium moisture with ambient RH, lost 2% moisture content both storage years. Spnuts lost 1.4% moisture content during storage of both crops. Percentage sound mature kernels (SMK) from Wpnuts decreased by 3.3% during 1994 crop storage and 6.6% during 1995 crop storage. Percentage SMK from Spnuts decreased 2.2 and 6.2% for the two storage years. Percentage sound splits (SS) for the Wpnuts increased 2.2% during 1994 crop storage and 4.2% during the 1995 crop storage. Percentage SS for Spnuts increased 2.4 and 6.1%, respectively. Changes in other grade factors were not consistent comparing percentage values for Wpnuts and Spnuts. Data indicate that maintaining grade and quality during FS peanut storage in west Texas will require knowledge of moisture content of peanuts placed into the warehouse and environmental monitoring in order to determine storage length. For 3- to 5-mo storage, it is recommended that FS peanuts have a moisture content close to 10% when placed into storage for peanuts to be above 7% when unloaded from the warehouse.