Common bean plant assessment, <em>Phaseolus vulgaris</em> L., under different row spacing

Abstract

The behavior of four common bean plant cultivars, Phaseolus vulgaris (Leguminosae-Faboideae), under different row spacing was assessed. A randomized complete block design with split plot treatments and four replications was used. Plots had a spacing of 30, 40 and 50 cm between rows and 10 cm between plants in each row (10 plants per meter). Subplots received IAC-Carioca Pyatã, IAC-Maravilha, Carioca and Pérola cultivars. The assessed traits were number of days to flowering (NDF), plant height at flowering (APF), number of days to maturity (NDM), plant height at maturity (APM), row closing (FECH) and PG (kg/ha). Results revealed significant effects of cultivars on traits under analysis; significant effects of spacing (P < 0.05) for FECH only; no significant effect on interaction. FECH showed a significant linear regression effect (R²=0.89) with row spacing. Cultivar IAC-Maravilha had highest average for NDF (57.08 days), NDM (105.58 days), APM (57.33 cm) and FECH (71.5 days). It did not differ from cultivars Pérola and Carioca for APF. Only cultivar IAC-Maravilha was different from the others for PG, with the lowest average in grain yield. Significant correlation was found between NDF and FECH (r = 0.95); between NDF and NDM (r = 0.95); FECH and NDM (r = 0.99); NDM and APM (r = 0.95); APM and PG (r = -0.98). Reduction of spacing between lines favored an increase in yield. However, cultivars with greater stature and later maturing cycles demanded a longer period to develop a canopy capable of closing row space. A lower yield was consequently produced