The goal of this work was to evaluate the effects of weeds on the growth of young Arabica coffee plants, at different densities of infestation. Seedlings of Mundo Novo coffee cultivar were transplanted at the stage of four to five pairs of completely expanded leaves, to pots with capacity of 25 dm³. The experiment was arranged in a randomized block in factorial design (4 x 4), with four weed species (Digitaria horizontalis, Brachiaria decumbens, Brachiaria plantaginea and Mucuna aterrima) at four planting densities coexisting with coffee (zero, two, four, and six plants per pot), with four replications. The weed species were planted 60 days after the coffee plant transplanting (0 DAT). On this date, and on the day the experiment was concluded, at 90 DAT, height, leaf area and stem diameter of the coffee plants were determined. At 90 DAT, measurements were also performed to determine the increase in height, leaf area and stem diameter of the coffee plants, as well as shoot and root dry matter of the coffee plants and weeds and coffee plant root density. Based onthese data, estimations were made for leaf mass ratio, stem mass ratio, root mass ratio, leaf area ratio and root system/shoot ratio of the coffee plants. The species M. aterrima presented the highest reduction rate for plant height, leaf area, dry matter of stem and leaves and girth diameter of the coffee plants. Among the grasses, B. plantaginea presented the highest reduction rate for plant height, leaf area, girth diameter and root density. A negative relation was observed between weed increase and growth variables, and between root mass ratio and root system/shoot ratio.
Arabica coffee; competition; integrated management; coexistence period; sustainability
