Revista Brasileira De Herbicidas 2002; 3(1): 33-38
Effect of the sequential application of glyphosate in Commelina benghalensis and Commelina dif/usa control in coffee crop
DOI: 10.7824/rbh.v3i1.369
Different strategies to reduce C. benghalens is and C. diffusa tolerance to glyphosate were studied in two field experiments in coffee. The effect of glyphosate sequential application at increasing doses and comparing the glyphosate formulations, glyphosate SA (isopropilamine salt) and glyphosate WG (ammonium salt) in the control ofthese species and the respective phytotoxicity was evaluated. No significant difference were foundamong formulations of glyphosate SA (2160 g/ha a.e.) and glyphosate WG (2160 g/ha a.e.), in C. diffusa and C. benghalensis controI. The sequential application of glyphosate WG at 1440 and 1080 g/ha a.e., with the second application 21 days after the first, was efficient for C. diffusa and C. benghalensis control, from 30 to 100 days after application (DAA). The tank mixture glyphosate SA+2,4-D, at 1080 + 1005 g/ha a.e., and the mixture diuron/paraquat at 300/600 g/ha resulted in accentuated phytotoxicity until 60 DAA. However, glyphosate SA and glyphosate WG in sequential application or in unique application, in the studied doses, caused accentuated phytotoxicity until 30 DAA, tuming to light phytotoxicity in the folIowing evaluations.
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