Interaction between potassium (K) and calcium (Ca) on the severity of Yellow Sigatoka in banana plants

The main control measure of Yellow Sigatoka (Pseudocercospora musae) in banana plants (Musa spp.) has been the planting of resistant varieties, and fungicide application. However, the use of adequately nourished plants is also emphasized as a complementary control method. This study evaluated the influence of interaction between potassium (K) and calcium (Ca) in nutrient solution on the severity of Yellow Sigatoka in banana. Evaluation included severity of disease, chlorophyll a and b contents, nutrient contents, and total dry weight (TDW). There was no interaction between concentrations of K and Ca for area under the disease severity progress curve (AUDSPC), although the AUDSPC increased in leaves 1 and 2 with increasing concentrations of K from 1 to 6 mmol L -1 . Increasing K led to a reduction in chlorophyll a and b contents, and in nutrients N, P, Mg, B, Cu, Zn, and Mn. TDW increased with increasing K. Therefore, high concentration of K causes nutritional imbalance in banana plants, and favors the severity of Yellow Sigatoka.