Physiological Quality of Maize Seeds Harvested with Different Moisture Contents and Submitted to Drying Delay

Abstract

Maize seeds harvested on ears with high moisture content must be dried quickly before the processing. However, the seeds pass for a drying delay due to an overload of the seed processing unit. In this period, seeds under bad storage present an increase on the deterioration speed, causing a decrease on germination and vigour. It was aimed to evaluate the physiological quality of seeds of the inbred line GNS25 submitted to a delay of drying. The seeds were harvested with 48.0, 40.5, 34.2, 29.4 and 23.5% moisture content and then submitted to a delay for 0, 6, 12, 24, 36 and 48 hours at 20, 40 and 60 °C. It was observed that there is no loss on germination of maize seeds when the drying delay happens at 20 and 40 °C with moisture content lower than 40.5% for up to 48 hours, but when harvested with 48% moisture content the changes are observed since the beginning of the delay; there are changes on maize seeds vigour after drying delay even in the milder temperatures (20 and 40 °C), mainly when the seeds are harvested in the most humid points (48, 40.5 and 34.2% moisture content); the drying delay at 60 °C causes decrease on viability and vigour of maize seeds in all the moisture contents and delay times; the amount of heat resistant protein is lower in the seeds harvested with 48%, intermediate in the seeds harvested with 34.2% and higher in the seeds harvested with 23.5% moisture content.