Moisture content at harvest and drying temperature on bean seed quality

Abstract

The physical quality and physiological performance of seeds may be influenced by numerous factors, including the moisture content at harvest and drying temperature. This study aimed at evaluating the physical quality and physiological performance of black bean seeds (BRS Campeiro cultivar), depending on the moisture content at harvest and drying air temperature. The experiment was conducted under a completely randomized design, in a 3 x 5 (moisture content at harvest x drying air temperature) factorial arrangement, with four replications. The samples were collected when the seeds reached the moisture contents of 35.2 %, 25.2 % and 16.6 %. After harvesting, the seeds were subjected to drying at temperatures of 30 ºC, 35 ºC, 40 ºC, 45 ºC and 50 ºC. The physical quality of the seeds was evaluated by determining the 1,000-seed weight and hectoliter weight. The physiological performance was evaluated by the germination speed index, germination first count, accelerated aging, dry matter, seedling shoot and root length and electrical conductivity. The increase in the drying temperature, regardless of the moisture content at harvest, reduces the physical quality and physiological performance of the seeds. When subjected to drying temperatures lower than 40 ºC, the seeds obtained from the earliest harvests show a better physical quality and physiological performance.