Nitrogen, phosphorus, and potassium fertilization on the incidence of brown eye spot in coffee crop in vegetative stage

Abstract

Balanced plant nutrition enhances coffee crop development and resistance to diseases such as brown eye spot (BES) caused by Cercospora coffeicola. The aim of this study was to evaluate the effects of fertilization with nitrogen (N), phosphorus (P), and potassium (K), named NPK, on the incidence of BES in rainfed coffee plantations that are in vegetative stage. The study was carried out in Lavras, MG, Brazil, in a plantation of the cultivar Mundo Novo IAC 379/19. The experimental design was randomized blocks, with six treatments and four replications. The fertilization levels used were 10, 40, 70, 100, 130, and 160% of the standard fertilization recommended for NPK. The incidence of BES and the number of coffee leaves in the period from May to December 2019 were evaluated. The areas under incidence (AUIPC) and under the number of leaves progress curve (AUNLPC) were estimated. Water potential and foliar chemical analysis were performed in April 2019, July 2019, and October 2019. The highest AUIPC was detected in plants with lower levels of fertilization. However, there was a reduction in the number of leaves due to the increase in the dose of NPK. The lowest leaf water potential occurred in July, when there was a greater intensity of the disease. The levels of NPK fertilization influenced their concentrations in the leaves, as well as other nutrients. The fertilization level of 100% favored the reduction of AUIPC, maintaining higher number of leaves and the nutritional balance in coffee plants.