Oxidative stress measurements can indicate the best dose and period of nitrogen fertilizer in white oat crop

The white oat crop is highlightedas an important winter alternative for agriculture in the South of Brazil. Oxidative stress (OS) generated by increased reactive oxygen species under stress conditions may promote unavoidable outcomes for production. Thus, we aim to standardize a simple quantitative spectrophotometric protocol to verify OSparameters in white oat growing under different nitrogen fertilization conditions. We also intend to be able to predict the best time, amount and conditions for nitrogen fertilization, based on OS parameters. The white oat culture arrangementwas a 2x4 factorial scheme, in a randomized complete block design. The treatments consisted of starter fertilizer and different topdressing periods, thus, we had two experimental systems, soybean/oat and maize/oat. We estimated the level of grain yield, total protein concentration, superoxide dismutase activity and malondialdehydeconcentration produced by different doses of fertilizer. Databases were subjected to variance analysis, compared the average and regression equations one and two aiming right time adjustment of nitrogen application by the joint analysis of production traits and oxidative damage. Our data support the hypothesis that OS measurements can indicate the best dose of N fertilizer and best N fertilizer period in white oat culture.