Influence of nitrogen content on the green effect caused by piraclostrobine in wheat plants

Abstract

Wheat (Triticum aestivum L.) is of great importance in the world, with nitrogen fertilization and disease control factors limiting productivity. Due to adequate nutrient supply and the use of fungicides, among these wheat products, a chemical group, strobilurins, has an increased activity of the enzyme nitrate reductase. The present work aimed to evaluate the physiological effect in wheat plants by the application of the fungicide in relation to the soil N content. The experiment carried out in the CEDETEG fields of the State University of the Western Center was conducted in a greenhouse under a 2x5 factorial scheme, with four replicates arranged in a randomized block, the first factor consisting of two levels: with application of pyraclostrobin and without application of pyraclostrobin. Second factor were different doses of nitrogen, applied in the form of urea, being: 0,0 kg ha^-1; 30 kg ha^-1; 41 kg ha^-1 ; 71 kg ha^-1; 101 kg ha^-1. Plants submitted to these nitrogen uptake present linear increase in their chlorophyll content. Increased fresh and dry mass were observed when the plants were submitted to application of pyraclotrobin. Plants sprayed with pyraclotrobin present lower levels of chlorophyll, but it is possible that the increase in mass obtained by plants is higher than the increase of chlorophyll, which causes the "dilution effect" in the final value of chlorophyll evaluated.