Yield and sanity of potato tubers (Solanum tuberosum L.) under different levels of basis saturation and calcium in soil

The study was conducted in the experimental area of Department of Agronomy, Campus CEDETEG -UNICENTRO (State University of Midwest) in Guarapuava (PR) Brasil, 25 degrees 23' 36" N, 51 degrees 27' 19" W, altitude of 1025 m, and regional climate classified as Cfb (Keppen). The aim of this study was to evaluate the effect of different levels of bases saturation and calcium in soil on the sanity, productivity and size of tubers in potato crops produced under field conditions. The planting of the potato cultivar Agata was held on February 19th, 2009. The nine treatments were arranged in completely randomized in a 3x3, with three levels of percent bases saturation (V%) in soil (50, 60 and 70%) and each with three levels of saturation with calcium (50, 60 and 70%). It was found that the effect of soil management with 60% of bases saturation and calcium from 60 to 70% leads to higher yield and larger size of tubers. This management also leads to lower levels of severity of common scab (Streptomyces spp.). The silver scurf (Helminthosporium solani Dur. & Mont.) showed low levels of severity, and management with bases saturation of 70% and calcium from 60 to 70%, and also the management of bases saturation of 60% and calcium 50% were the most efficient alternatives to reduce the severity of this pathogen.