VIEW ARTICLE

Disease Control and Pest Management

Effect of Mineral Fertilizers on the Incidence of Blossom-end Rot of Watermelon. M. Cirulli, Istituto di Patologia vegetale, University of Bari, 70126 BARI, Italy; F. Ciccarese, Istituto di Patologia vegetale, University of Bari, 70126 BARI, Italy. Phytopathology 71:50-53. Accepted for publication 5 June 1980. Copyright 1981 The American Phytopathological Society. DOI: 10.1094/Phyto-71-50.

Potassium and phosphorus fertilizers had no effect on the percentage of blossom-end rot of watermelon in either medium-textured sandy loam soil or in fine-textured loam soil. In sandy loam soil, in 1974, the percentage of blossom-end rot in the Charleston Gray watermelon was significantly reduced by 8.06 and 8.24% in calcium (20 kg/100 m² gypsum)- and nitrogen (5 kg/100 m² urea [44-45% N])-treated plots, respectively. In loam soil, in 1975, treatment with calcium reduced the percentage of blossom-end rot in cultivars Crimson Sweet and Charleston Gray. In 1976, in loam soil the incidence of blossom-end rot in Crimson Sweet also was significantly reduced and marketable yield was increased with increasing levels of gypsum. In this experiment the increasing levels of nitrogen had no effect on disease incidence, but significantly increased the yield of marketable melons.