Abstract

NAJUL, Carlos  and  ANZALONE, Alvaro. Weed control with vegetal mulch in black beans (Phaseolus vulgaris L.) crop.. Bioagro [online]. 2006, vol.18, n.2, pp.75-82. ISSN 1316-3361.

A trial was conducted to evaluate the effect of different kinds of weed control on the yield components of black beans (Phaseolus vulgaris L.). Eight treatments consisting in the use of soil mulches based on straw of Panicum maximum Jacq. besides chemical and manual methods of weed control were used as follows: chopped, whole, very finely chopped, and composted straw; a chemical control (pendimethalin+linuron), two types of manual control (weeding for the whole crop cycle, and weeding starting at flowering), and a control (always with weeds). A randomized block design with eight treatments and four repetitions was used. It was found that all soil mulch methods reached more than 90% weed control on the first evaluation (28 days after crop emergence), while in the second (42 days) only in the chopped straw treatment the weeds were controlled more than 90%. The largest yield was obtained with the use of composted straw with a value of 2852.53 kg·ha^-1, even though this treatment did not produce the highest weed control, which was attributed to the additional benefits probably obtained by the incorporation of this organic material to the soil. The rest of the mulch treatments, as well as chemical control and manual weeding showed similar results each other, but always greater than the control.

Keywords : Soil covering; herbicides; yield components; Panicum maximum.