Effects of nitrogen, phosphorus, potassium and calcium nutrition on strawberry anthracnose

The effects of a range of concentrations of four nutrients - nitrogen, phosphorus, potassium and calcium - in fertilizer solutions on the severity of anthracnose on strawberry cv. Nyoho cultivated under a noncirculation hydroponics system were determined after inoculation with Colletotrichum gloeosporioides. Crop growth and tissue nitrogen, phosphorus, potassium and calcium contents of the entire above-ground parts of the plant were also investigated. Elevated nitrogen and potassium concentrations in the fertilizer solution increased disease severity in contrast to phosphorus and calcium. Treatment with either NH4 or NO3 nitrogen was not significantly different. The dry weight of the strawberry plants increased significantly with elevated concentrations of nitrogen (R-2 = 0.9078) and phosphorus (R-2 = 0.8842), but was not influenced by the elevated amounts of potassium (R-2 = 0.8587) and calcium (R-2 = 0.6526) concentrations.