Evaluation of the herbicides Crosser and Vaquero for weed control in tropical grasslands.

Abstract

During the 2001

rainy season, two experiments were conducted in La Mancha,

Veracruz, Mexico, in order to evaluate the effect of the

herbicides Crosser (15 g of picloram + 150 g of 2,4-D/L) and

Vaquero (30 g of triclopyr + 120 g of 2,4-D/L) for controlling

Lagascea mollis Cav. and Baltimora recta L. in a grassland of

Cynodon plectostachyus Vanderyst. In 2002, the experiments

were repeated in La Colonia Independencia, Ver., in a

grassland of Digitaria decumbens Stent., infested with Senna

obtusifolia (L.) Irwin & Barneby. Both herbicides, Crosser

and Vaquero were applied at 0.75, 1, 1.25, 1.5 and 2 l/100 l of

water; Full-Mina 4 (480 g of 2,4-D/L) at 1 and 2 l/100 l of

water, and Esteron 47-M (400 g of 2,4-D/L) at 2 l/100 l of

water, were also evaluated and a weeded control was

included. A Completely Randomized Block Design with four

replications was used for all the experiments. Weed control

and grass toxicity were evaluated at 15, 30 and 60 days after

treatment application. Crosser controlled B. recta and S.

obtusifolia at 0.75 l/100 l of water, whereas to control L.

mollis, it was necessary to apply it at 1.5 l/100 l of water.

Vaquero also controlled B. recta and S. obtusifolia at 0.75

l/100 l of water, but it had no good control of L. mollis. None

of the herbicide treatments caused any toxicity to the grasses.