Competition with spreading dayflower (Commelina diffusa L.) can affect the agronomic characteristics and mineral content of common bean grains

The objective of this study was to evaluate the effects of the presence of Commelina diffusa weeds on the agronomic characteristics and mineral content of bean grains (Phaseolus vulgaris L.). The experiments were conducted using a completely randomized design with five replications in a greenhouse. The treatments consisted of two bean cultivars (BRS Ametista and BRS Estilo) grown in the presence and absence of the weeds. The weeds affected the agronomic and mineral characteristics of the varieties; caused a decrease in the number of leaves; reduced the chlorophyll content in the leaves; and reduced the nitrogen, phosphorus and iron contents in the grains. Competition with spreading dayflower did not cause significant effects on the stem diameter or the levels of potassium, calcium, and magnesium in the grains. The BRS Estilo variety was less affected by weed competition than BRS Ametista and showed higher values for the number of leaves, chlorophyll content, and accumulation of manganese and iron in the grains.