Optimization of Split Between Windrow and Wagon Curing of Peanuts

Abstract

ABSTRACT CURRENT peanut production practices involve a two-stage drying or curing procedure in which peanuts are dug from the ground, placed in windrows in the field for partial drying, and then combined and dried artificially in bins or wagons until a moisture content suitable for marketing is achieved. As energy costs have increased during recent years, interest has grown in reducing energy consumption in the production of all agricultural commodities. One technique for reducing energy consumption in peanut curing is to increase field drying and reduce the artificial drying in wagons. Because the sun provides the energy used in field or windrow drying, total drying costs would be reduced by increasing the amount of windrow drying. However, as the peanuts are left in the field for longer periods of time they may be subject to higher field losses which could more than offset the savings in energy costs. The optimum time for combining occurs when the rate of increase in costs from field losses is equal to the rate of decrease in costs for wagon drying. In order to predict when the optimum time for combining of peanuts occurs, it is necessary that we be able to predit: (a) the drying which will take place in the windrow under various conditions, (b) the field losses to be experienced under different weather conditions, and (c) the costs for drying in wagons under different weather conditions. Vedak (1974), Vedak and Young (1976), Young (1977), and Steele and Wright (1977) have developed computer simulation procedures for predicting the drying of peanuts in the windrow under various weather conditions. Vedak (1974), Vedak and Young (1976), Chhinnan and Young (1978), and Troeger and Butler (1979) have described simulation procedures for predicting the drying rates of peanuts in wagons or bins. No reports were found in the literature of studies in which field losses were related to condition of peanuts and weather conditions. The objectives of this study were to develop procedures for predicting field losses, to link the field loss predictions with computer programs for simulating windrow and wagon drying, and to determine the optimum split between windrow and wagon drying based on weather data for specific periods.