Manejo da temperatura do ar na secagemintermitente de sementes de arroz irrigado

Abstract

This work aimed to maintain the physiological quality of rice seeds through the adequate use of air temperatures during the drying. The rice seeds cultivar El Paso L-144 were dried in an intermittent drying system, with capacity for 11.000 kg, under four drying conditions: 1) at constant temperature of 40°C; 2) constant temperature of 60°C; 3) at gradual increasing temperature (since 60°C) during the first two hours and constant temperature of 60°C until the end of the drying cycle; 4) at gradual increasing temperature (since 60°C) in the first two hours and gradual decreasing temperature until the end of drying cycle. The seeds were kept in bags made of trussed plastic yarns at room temperature and local environment conditions, for the period of 180 days and analyzed how much the physiological quality at zero, 90 and 180 days. The storage system was conventional. The vigour (through accelerated aging, field emergency test and cold test) test were analyzed. In conclusion, the intermittent drying process at a constant temperature of 60° C is don't preserves the seed quality; finally, the gradual increased temperature also preserves the physiological quality of rice seed.