AMBIENTES PROTEGIDOS PARA EL ALMACENAMIENTO TEMPORAL Y EL SECADO DEL FRIJOL (Phaseolus vulgaris L.) EN EL CAMPO.

The objective of this work was to evaluate sheltered environments for temporal storage and drying in the field of common beans harvested in hill-side agriculture in Mesoamerica. This study was conducted in Pérez Zeledón and Buenos Aires during the rainy season of year 2007. The proposed design modifies the rustic structures traditionally used by farmers, includes cross-ventilation, floor elevation, remotion of lateral walls, and low-cost, locally-available materials. We also applied principles of energy balance and used reflective materials that reduced energy and heat load. Three colors of plastic covers were evaluated: transparent, black and gray, of 0,0038 cm thickness. The control treatment was the design and plastic cover used by farmers (four treatments). We measured temperature and relative humidity inside (0,20 and 1,25 m deepth) and outside the shelters during 16 days, over two measurement periods of 8 consecutive days each, in three farms (replications). Seed humidity and cooking time were also evaluated. Reflective plastic materials and the bioclimatic design deployed significantly improved the microclimate within the shelters, and resulted in substantial reductions in cooking time of bean seeds in comparison with the traditional design with transparent plastic used by farmers. [ABSTRACT FROM AUTHOR]