Several carioca-grain cultivars of common bean with early cycle and determinated growth were recently released. For this type of cultivar can express its productive potential, among other factors, it is necessary to adapting management of nitrogen (N) fertilization. The objective of this work is to study the N uptake rate and the topdressing N management in early cycle common bean cultivars and determined growth. In the Experiment I will be adopted the randomized block design in a split-plot design with four replications. The treatments will be composed of four common bean cultivars [Pérola (normal cycle) and IAC Imperador, IPR Andorinha, and IPR Curió (early cycle)] and subplots for sampling dates performed every two weeks during the crop cycle. In the Experiment II will be adopted the randomized block design with four replications. The treatments will be comprised by a 3x7 factorial combination, with three common bean cultivars (IAC Imperador, IPR Andorinha, and IPR Curió) and seven management of N fertilization [M1: control - without nitrogen early applied or topdressed; M2: 90 kg ha-1 N in V3; M3: 90 kg ha-1 N in V4; M4: 45 kg ha-1 N in V3 + 45 kg ha-1 N in R5, M5: treatment reference for readings chlorophyll meter, 90 kg ha-1 N in V3 + 90 kg ha-1 N in R5; M6: treatment that will receive application of N (30 kg ha-1) only when the chlorophyll meter readings indicate sufficiency N index < 90%, in relation to treatment M5; M7: early application of 90 kg ha-1 N (one day before sowing)]. In the Experiment I will be evaluated: leaf area and leaf area index, accumulation and partitioning dry matter (DM) and N in the shoot, accumulation rate of DM and N in the shoot, concentration of nutrients in the leaves, yield components, grain yield, and concentration and removal of N in the grains. In the Experiment II will be evaluated: concentration of nutrients in the leaves, DM and N accumulation in shoots, yield components, grain yield, protein concentration in grain, and N use efficiency. In both experiments the data will be submitted to analysis variance and treatment means will be compared by Tukey test at 5% probability. In the Experiment I, the results of the sampling dates will be evaluated by regression analysis.
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