Qualidade fisiológica de sementes de milho com inseticida antes e após o armazenamento

Abstract

Maize is among the main crops with economic and cultural importance in the world, and the second most important to Brazilian economy. In order to meet the market s requirements, it is necessary to produce high quality seeds and avoid possible losses due to pests and disease. Seed managementhas been considered an efficientway to pestcontrol, but some of these products may cause phytotoxicity problems in the seeds after sowing or during storage. In this context, this study aims to evaluate the influence of active principles: clothianidin (Poncho 600), fipronil (Standak top), and deltamethrin (K-obiol) on the longevity of maize seeds IPR 164 from commercial lots of 2014/15 from the Agronomic Institute of Paraná IAPAR, during a six-month storage period. Two experiments involving seed treatment using insecticide were conducted: one in which the seeds were treated before being stored and theother in which they were treated at the time of planting,afterstorage.The seeds were treated following the manufacturer's recommendations, with K-obiol, Standak top, Poncho and water (control), and stored in laboratory. The experiment was conducted in a completely randomized design (CRD) with four replications in the Seeds and Plants Assessment Laboratory / UNIOESTE. For a period of six months, monthly, starting June 2015, tests were performed to verify:germination, infested seed, seedling growth, mass of a thousand seeds, determining the water content, fresh and dry weigh to froot and shoot, and emergence in sand to monitor the physiological seed quality during storage. In general, after the evaluation of the tests, it was concluded that the tested insecticides did not reduce the physiological quality of the maize seeds; there was no difference between the previously treated and theafter storage and after sowing treated seeds in quality. At the end of the period, the seeds maintained a germination percentage above the established by legislation