Fertilización con nitrógeno, fósforo, potasio y calcio en mora (Rubus glaucus Benth.): Efecto sobre Antracnosis, bajo condiciones protegidas

To propose alternatives for management Anthracnose ( Colletotrichum gloeosporioides ) in blackberry cultivation, an experiment was performed to estimate the effect of nitrogen, phosphorus, potassium and calcium on C. gloeosporioides strain 52 infections.  A randomized complete block design was used with a treatment arrangement corresponding to an orthogonal central composed design. To evaluate the relationship between fertilization levels and the severity of the disease, an artificial inoculation was carried out on blackberry stems with thorns, by 0.5 cm mycelium discs at a concentration of 9.53x10 4 conidia, registered disease severity (S), incubation period (PI) and development rate (r). A cluster analysis was performed on the severity variable, a Pearson correlation analysis between variables, as well as a regression to estimate the effect of the nutrients applied on the severity of strain 52.  The treatments were concentrated in four groups with S, PI and Tr between 15.9% to 91.8%, 9 to 15.3 days and 0.0254 to 0.0468, respectively.  Positive and significant correlation was observed between Sf and Tr (P<= 0,001), and negative and significant, between PI with Sf and Tr (P < 0,001).  Finally, through the regression analysis, a linear model was generated that allowed us to verify the decrease in severity with the increase in the dose of nitrogen and the increase in this with the growth of phosphorus and calcium levels.