Influence of the mineral nutrition on intensity of brown-eye spot in youngcoffee plants

The experiment was carried out at the coffee nursery of the Universide Fede ral de Vicosa, in Vicosa, MG, Brazil, using nutrient circulating solution t o evaluate the intensity of brown-eye spot (Cercospora coffeicola), variety Catuai Vermelho, as a function of N and K. A completely randomized design with 16 treatments, three replicates, and two plants per plot was used in a factorial with four levels of K (3, 5, 7 and 9 mmol/L) combined with four levels of N (3, 7, 11 and 15 mmol/L). After seven inoculations and evaluati ons, the plants were picked. Total dry matter production, total leaf area, and the area below the curve of progress (AACP) for the total number of lea ves were not influenced by the levels of K, but increased with increasing l evels of N. There was increase in AACP areas for the number of lesions per leaf and defoliation, with the increase of K levels, and a reduction of N l evels. The increase in K levels reduced the Ca and Cu leaf contents, indica ting possible relation between its contents and the increase of the disease . The P, Mg, Mn, and Fe leaf contents were not influenced by the K levels, and had a small reduction with increased N contents in the nutrient solutio n, increasing thereafter.