Application of Calcium and Sulfur in the Severity of Puccinia coronata f. sp. avenae

Among the diseases that manifest in the cultivation of oats (Avena sativa), leaf rust, caused by Puccinia coronata f. sp. avenae, has been shown to be the most destructive, being responsible for the decrease in quality and grain yield. Nutritional balance can contribute to plant resistance to disease. In order to evaluate the effect of different doses of calcium and sulfur on leaf rust severity and on the productivity of the IPR Afrodite white oat cultivar, an experiment was installed in the municipality of Ponta Grossa-PR. The experimental design used was randomized blocks, with 5 treatments and 4 repetitions. The treatments consisted of different doses of SE-SUPER fertilizer (CaO 31% + S 13.50%) applied at sowing: T1 (control, 0Kg.há-1), T2 (50Kg.há-1), T3 (100kg.ha-1), T4 (150kg.ha-1) and T5 (200kg.ha-1). The assessments of leaf rust incidence and severity are carried out weekly from the first symptoms, by quantifying the proportion of the affected host tissue. From the first assessment, weekly assessments were carried out, making it possible to calculate the area under the disease progress curve (AUDPG). For the determination of productivity, the yield in kg of grains / ha was calculated, based on the harvested experimental area. There was a difference between treatments for the severity of rust in the six evaluations performed. All doses were equivalent in reducing the AUDPG of the disease, but the treatments with 150 and 200 kg.ha-1 of SE SUPER, presented the highest percentages of reduction, 47.21 and 48.00%, respectively. There was no difference in the productivity obtained. Other management strategies must be associated with fertilization with calcium and sulfur to control rust. Other management strategies should be associated with fertilization with calcium and sulfur, contributing to the rational use of pesticides and reducing pollution.