Changes in the effects of weathering and mechanical damage on soybean seed during storage.

摘要

The physiological quality of seeds of early and semi-early soybean cultivars may be lower than desired as a consequence of unfavorable climatic conditions occurring during the harvest period. The objective of this research work was to evaluate the effects of field weathering as well as the levels of mechanical damage at harvest on soybean seeds during storage, as determined by the tetrazolium (TZ) test. Seeds from two lots of each of three semi-early soybean cultivars (CD 214 RR, BRS 184, and Embrapa 48) with two different levels of initial vigour (high and medium) on the basis of the germination and accelerated ageing tests were stored in Mandaguari County, in the State of Parana, in storage facilities without environmental (temperature and relative humidity) control. Seed evaluations were performed using the tetrazolium test at 45 d intervals for a total of 225 d of storage. The parameters determined by the tetrazolium test were weathering (TZ class 3), and mechanical damage (TZ classes 6 to 8). It was concluded that weathering and mechanical damage injury increased substantially during storage, progressing linearly for the three cultivars studied and independent of the initial level of seed lot vigour. The classification of mechanical damage was only divided into two categories (immediate and latent damage) therefore further evaluations will be needed to accurately determine actual characteristics as well as their correlation with the loss of physiological quality of soybean seeds during storage.