Qualidade fisiológica de sementes de soja submetidas ao tratamento com inseticida em tambor giratório metálico

Abstract

The physiological quality of seeds is necessary for the success of rural activity condition. The soybean crop is the main crop sown in Brazil, which is one of the largest producers and exporters of this product. Despite the success of soybean in Brazil, it is still possible to observe, in rural properties in Cascavel, state of Paraná, the use of saved soybean seeds (named in this work as seeds for own consumption), grains that farmers keep with them for the next year sowing. In this attempt to reduce the cost process, the producer makes the treatment of seeds for own consumption with pesticides on his own farm, with the aid of an instrument called metal drum. This is meant to shelter the seeds and pesticides and, with a mechanical circular motion, distribute the defensives over the seeds. The objective of this study was evaluating the physiological quality of soybean seeds for own consumption under treatment in metal drums through germination, vigor tests and identification of mechanical damage. The experimental design was completely randomized, factorial 2 X 3 with three cultivars and two treatments: one with and another without treatment in drums. Means were compared statistically by Tukey test at 5% of probability. In the germination test, the N5909 and Apollo cultivars with treatment in drums had higher percentages of normal seedlings, but it was less than 80%. For vigor tests, treatments in drums exhibited higher percentage of abnormal and dead seedlings, indicating that, under stress conditions, damage to the seeds treated in metal drums have influence on the physiological quality of seeds. In the tetrazolium test for identifying damages, all three treated cultivars had mechanical damage. Thus, the seed for own consumption treated in drums showed low vigor and presence of mechanical damage. The seed for own consumption that has not been subjected to the treatment also showed low vigor, but also had lower mechanical damage when compared to the seeds who received treatment.