Época e horário de aplicação de fungicida sobre a qualidade de sementes de arroz

Abstract

The experiment was conduced in Pelotas – RS, on the 2005 – 2006 harvest. The study had by it is objective to determine all losses related to bad seed quality, considering the flowering stage and fungicide application, in order to control diseases. The rice variety used on the study was “Combat”, and the fungicide was the “Folicur 200 CE (tebuconazole 200g/L)”, at 0,5L /ha dosage of it is commercial product. It was tested on a factorial combination, which are: three flowering stages (5%, 50% e 80%) and three application periods (9 o’clock, 13 o’clock and 17 o’clock), with four repetitions. The parameters to be evaluated were: Germination test, First counting test, sanity test, vigor test ( cold ), average day of seed emergency and seed emergency on soil. The results demonstrated that the fungicide application at more advanced stages of flowering damages seeds physiological quality, as so the fungicide application period may damage seeds vigor. In concern to the sterility, the fungicide application at more advanced stages of flowering does not avoid seed sterility, as so as periods of higher temperatures are less recommended. In order to achieve seed sanity control, the period of fungicide application came to be more important than the flowering stages whitch treatments were applied.