| Abstract: The objective of this work was to establish the diagnostic leaf and the nitrogen sufficiency index (NSI) values most appropriate to estimate N requirement by the 'Pérola' common bean (Phaseolus vulgaris), based on chlorophyll meter monitoring. The diagnostic leaf was defined in an experiment with five N rates, and up to four sampling dates of the diagnostic leaves were evaluated (first, second, and third completely expanded leaves from the apex). The NSI was established in two crop seasons, under six N managements: M1, 40 kg ha-1 N at sowing + 80 kg ha-1 10 days after emergence (DAE) + 80 kg ha-1 20 DAE (reference rate); M2, 20 kg ha-1 at sowing + 40 kg ha-1 10 DAE + 40 kg ha-1 20 DAE (recommended rate); M3, 20 kg ha-1 at sowing + 30 kg ha-1 when... |
