Response of potato crop to application of nitrogen and plant growth regulator

Abstract

The use of plant growth regulators in potato crop (Solanum tuberosum L.) associated with nitrogen (N) management may be an alternative to increase tuber yield. The aim of this work was to evaluate the effect of nitrogen fertilization and application rates of calcium prohexadione on plant growth, photoassimilate partition, and tuber yield of the Agata potato cultivar. Two experiments will be carried out, one in a greenhouse and another in the field. The field experiment will be carried out in two locations. In the greenhouse, the experimental design will be in randomized blocks in a 4x4 factorial scheme, with four replications. The treatments will be represented by four rates of plant growth regulator (0, 50, 100, and 200 g ha-1 a.i.) and four times of evaluation (23 DAE, 33 DAE, 43 DAE, and end of cycle). In the field, the experimental design will be in randomized blocks in a 2x4 factorial scheme, with four replications. The treatments will be represented by two levels of N supply (Medium = 120 kg ha-1 and High = 240 kg ha-1) and four rates of plant growth regulator (0, 50, 100, and 200 g ha-1 a.i.). In the greenhouse, the morphological, biochemical, dry matter production (DM), carbohydrate and soluble sugar partition in the plant, and tuber yield will be evaluated. In the field, the morphological characteristics, the accumulation of DM in the plant and its partition for the tubers, the tuber yield and the uptake and removal of N by the potato crop will be evaluated. In both experiments, the data obtained will be submitted to analysis of variance. The means of the qualitative factors will be compared by the Tukey test at 5% of probability, while the effects of the rates of plant growth regulators will be evaluated by regression analysis. (AU)