POTENTIAL OF GRAIN AERATION WITH NATURAL AIR IN BOTUCATU-SP, BRAZIL

Abstract

Grain aeration using ambient air was simulated under weather conditions in Botucatu. Grain aeration potential was evaluated based on criterion of operating ventilation system if dry bulb temperatures are equal or lower than dew point temperatures of grain voids air. Hours in the favourable periods for safe aeration were computed, from 1971 through 1975 and 1977 through 1981, for allowed maximum dry bulb temperatures of 25°C, 23°C, 21°C, 19°C, 17°C, 15°C and 13°C. If maximum dry bulb temperatures are higher than 19°C, the selective aeration can be realized all the year. For maximum dry bulb temperatures between 13 and 19°C, selective aeration is suitable in April, May, June, July, August and September, being the best selective aeration conditions in June and July. Rewetting risks arise in the following order: rice, soybean, corn, wheat, bean and sorghum.