Resfriamento dinâmico, armazenamento e qualidade fisiológica de sementes de soja

Abstract

This study aimed to evaluate the physiological quality of soybean seeds subjected to cooling at the bagging and kept refrigerated in storage with controlled temperature or not. The seeds were stored in a cold warehouse and another not. Were used soybean seeds, variety M7639RR produced in the 2013/2014 crop, located in Pedra Preta County, State of Mato Grosso, Brazil. A seed lot was divided into two portions and each was subdivided into three parts (sub lots), each subjected to a treatment. In the first and second sub lots, the seeds were subjected to cooling at the time of bagging at 13 °C (T1-SRE13) and 17 °C (T2-SRE17), respectively. In the third, the seeds were not cooled at the time of bagging (T3-SNRE). The sub lots were kept on a conventional warehouse and a cold warehouse. During storage were monitored air temperature, relative air humidity and the temperature of the seeds. The seeds were submitted to germination, tetrazolium (viability and vigor), accelerated aging and emergency. The samples were collected at six times (0, 45, 90, 135, 180 and 225 days). The experimental design was completely randomized in a factorial 3x2x6 (three cooling procedures, two storage conditions and six evaluation periods). It was concluded that the artificial cooling to 13ºC in bagging followed by maintenance in cold storage under 20 °C ensures the preservation of physiological quality of soybean seeds for 225 days. The temperature of the soybean seeds subjected to a dynamic cooling enter into thermal equilibrium after 20 to 30 days, both in storage with and without cooling. The germination of seeds subjected to a dynamic cooling is maintained during storage under controlled environment conditions or not.