The utilization of techniques that allow the maximization efficiency of nitrogen use by the common bean is important to increase grain yield and quality, to decrease production cost, and to avoid environmental contamination. The objective of this work was to evaluate the performance of common bean (Phaseolus vulgaris L.) in response to levels of sidedressed nitrogen applied on the V4 and on the beginning of R7 development stages, in no-tillage system. A randomized complete block design, in a 2 x 4 factorial scheme, with four replications was used. The treatments were a combination of two N levels (0 and 90 kg ha-1) in the V4 stage and four N levels (0, 30, 60, and 120 kg ha-1) in the beginning of the R7 stage. When nitrogen fertilization was not used in V4 stage, the application in the beginning of R7 stage increased the common bean grain yield in no-tillage system. Nitrogen application in the V4 stage (90 kg ha-1) provided the maximum grain yield. When nitrogen was applied in the V7 stage, its was necessary greater levels for obtaining the same yield. When nitrogen fertilization was used in the V4 stage, the application in the beginning of the R7 stage did not increase common bean grain yield. Nitrogen side dressing in the V4 stage was more efficient than in V7, resulting in higher grain yield per nutrient unit. The application of nitrogen in the V4 stage and in the beginning of R7 development stage, increased grain protein content.
Phaseolus vulgaris; nitrogen fertilization; time of application; protein
