Respostas fisiológicas de sementes de milho a tratamentos químicos

Abstract

Brazil is the third largest producer of corn, and grain yield of the country has grown steadily, rising from 1,874 kg ha-¹ on average in 1990 to approximately 4,000 kg ha-¹ medium today. This increased productivity is due in part by the use of modern technologies by farmers, such as hybrid or improved cultivars that are adapted to growing regions, seed treatments and improvements to the management conditions and cultivation of culture. Among the factors that affect the grain yield of maize tands out the attack of pests and diseases. For protection of maize seedlings can be used seed treatment with insecticides and fungicides. The objective of the study was to evaluate the physiological effects of corn seeds submitted to different chemical treatments. The study was conducted at the Seed Laboratory, Federal University of Pampa, Itaqui, RS, in a completely randomized design with ten treatments and four replications. The treatments were: fludioxonil at dosege 75, 150, and 225 mL/100 kg seed, thiamethoxam at dosage 60, 120 and 180 seeds mL/60.000, fludioxonil + thiamethoxam at dosage 75, 150 and 225 mL/100 kg of seeds + 60, 120 and 180 and untreated seeds mL/60.000 application. The variables evaluated were a thousand seed weight, germination, germination rate, cold test, accelerated aging, seedling length, fresh weight of seedlings and seedling dry matter. In general seed treatment resulted in a better growth of maize seedlings compared to no application. Among the products tested the fungicide fludioxonil stood out in relation to insecticide tiametoxan, with the best results in the variables: cold test, accelerated aging, seedling length, fresh weight, regardless of dose estimates.