The presented field trial was conducted at the Universidade Estadual de Ponta Grossa, Paraná State, Brazil, on a Dark Red Latossoil, to evaluate the availability and efficiency of herbicides metolachlor and metribuzin + metolachlor in the control of weeds in the potato crop. The experiment was laid out in a randomized block design with nine treatments and four replications as follows: metolachlor (1.92; 2.88 and 3.84 kg a.i/ha); metribuzin + metolachlor (0.24 + 1.68; 0.36 + 2.52 and 0.48 + 3.36 kg a.i./ha); metribuzin (0.48 kg a.i/ha); weed free and weedy. Planting was conducted in October 1995, using the cultivar Elvira, with plants spaced 0.70m x 0.35m. The predominant weeds were: Brachiaria plantaginea (capim-papuã), Digitaria horizontalis (capim-milhã) and Galinsoga parviflora (fazendeiro). Evaluations were made 15, 30 and 45 days after treatment applications. The following herbicides and doses were efficients: metolachlor (2.88 and 3.84 kg a.i/ha) for control of capim-papuã and capim-milhã; mixture metribuzin + metolachlor ( 0.36 + 2.52 and 0.48 + 3.36 kg a.i/ha) for control of capim-papuã and capim-milhã; metolachlor (1.92, 2.88 and 3.84 kg a.i/ha) and metribuzin + metolachlor (0.24 + 1.68, 0.36 +2.52 and 0.48 + 3.36 kg a.i/ha) for control of fazendeiro. Potato plants did not show any visual symptoms of damage attributed to herbicides.
Solanum tuberosum L.; chemical control; herbicides
