Resumo

ESQUEDA-ESQUIVEL, V. A.; ROSAS-GONZALEZ, X.  e  BECERRA-LEOR, E. N. Assessment of weed control by residual herbicides in a soursop plantation. Rev. Chapingo Ser.Hortic [online]. 2010, vol.16, n.1, pp.5-12. ISSN 2007-4034.

The objective of this study was to determine the effect of residual and non residual herbicides on weed control in a soursop (Annona muricata L.) plantation established in a square system at Los Idolos, Actopan, Ver. The randomized complete block design with four replications was used. The experimental plots had a 5 x 5 m area, each with one soursop tree in the center. Twelve treatments were evaluated (diuron + hexazinone at 1.09 + 0.14, 1.63 + 0.20, 0.87 + 0.33 and 1.31 + 0.49 kg a.i.·ha^-1, diuron + paraquat at 0.20 + 0.40 and 0.30 + 0.60 kg a.i.·ha^-1, oxyfluorfen + glyphosate at 0.48 + 0.71 kg a.i.·ha^-1, oxyfluorfen + paraquat at 0.48 + 0.40 kg a.i.·ha^-1, paraquat at 0.40 kg a.i.·ha^-1, glyphosate at 0.71 kg a.i.·ha^-1, glufosinate at 0.30 kg a.i.·ha^-1 and a weedy check). The dominant weed species was crowfoot grass [Dactyloctenium aegyptium (L.) P. Beauv.], 10 broadleaf weed species were also present. Weed control was evaluated at 15, 30, 60 and 90 days after application (DAA), and dry weed weight was quantified at 90 DAA. It was found that diuron + paraquat at 0.30 + 0.60 kg a.i.·ha^-1 was the treatment with the highest control of D. aegyptium. Broadleaf weeds were efficiently controlled with diuron + hexazinone at 1.63 + 0.20, 0.87 + 0.33 and 1.31 + 0.49 kg a.i.·ha^-1. Weed biomass production was lower with residual herbicides than with non-residual herbicides.

Palavras-chave : Dactyloctenium aegyptium; broadleaf weeds; dry weight of weeds; pesticides.