Initial growth characteristics of two coffee cultivars under different water regimes and levels of NPK fertilization

The experiment objectified to evaluate the effects of water regimes (irrigation and no irrigation) and fertigation, combined with fertilizer doses for N, P and K, during the initial growth phase of two coffee cultivars, Obata and IAPAR-59, in the north-western region of the state of Parana, Brazil. The experimental design was the completely randomized in a split-plot arrangement. The main plots were represented by fertilizer doses, corresponding to 15, 30, 45 and 60 g m(-1), for N and K, and to 3, 6, 9 and 12 g m(-1), for P, which are equivalent, respectively, to percentages of 50%, 100%, 150% and 200% of the dose recommended for each nutrient. The sub-plots were constituted by lines of plants that received the water regimes. Were evaluated stalk diameter, length of the first plagiotropic branch and its number of inter-knots. The treatments were analyzed separately for each cultivar of coffee. Fertigation and irrigation favored the initial growth of both coffee cultivars. For the IAPAR-59 cultivar, the number of inter-knots was upper only with fertigation. The number of inter-knots increased with irrigation and decreased in no irrigation regime, linearly, for IAPAR-59 and Obata, respectively, in function of the NPK doses increasing. In fertigation, it was observed reduction of stalk diameter at doses higher than the lowest dose tested, for IAPAR-59, while the largest number of inter-knots was obtained with the highest dose used, for Obata.