Effect of Row Spacing on Weed Competition with Snap Beans (Phaseolus vulgaris)

Abstract

Five field experiments were conducted with snap bean (Phaseolus vulgarisL.) row spacings of 15, 25, 36, 46, and 91 cm, all of which were seeded at a constant density of 43 plants/m2. When weeds were allowed to emerge with the crop, row spacings of 15 to 36 cm suppressed weed growth by 18% compared to the conventional 91-cm row spacing. When weeds were controlled for the first half of the season, row spacings of 15 to 36 cm suppressed weed growth by 82% compared to the 91-cm row spacing. The effect of the 46-cm row spacing on weed growth was variable. Weed suppression by narrow rows was explained by a higher rate of snap bean canopy closure in narrow rows. Snap beans in row spacings of 15 to 46 cm produced similar yields and were higher by an average of 23% than yields produced by snap beans in 91 - cm rows.