Open AccessHerbicide performance in the control of Conyza spp. where three plant heights
Author(s) -
Theodoro Schneider,
Juliane Nicolodi Câmera,
Jana Koefender,
Mauro Antônio Rizzardi,
Mário Antônio Bianchi,
Ana Paula Rockenbach
Publication year - 2021
Publication title -
bioscience journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 19
eISSN - 1981-3163
pISSN - 1516-3725
DOI - 10.14393/bj-v37n0a2021-53718
Subject(s) - glyphosate , paraquat , glufosinate , biology , herbicide resistance , diquat , agronomy , weed control , clopyralid , pesticide , horticulture , biochemistry
Intensive use of the herbicide glyphosate has led to herbicide resistant Conyza spp. populations. Thus, there is a need to indicate alternative herbicides and the appropriate developmental stage for controlling these populations. This study identifies alternatives for controlling glyphosate-resistant horseweed, with treatment applications at different plant heights. For this purpose, field experiments were conducted in the 2016/17 and 2017/18 crop years. The evaluated treatments were: glyphosate (540 g ae ha-1), glyphosate (1080 g ae ha-1), glyphosate (2160 g ae ha-1), glyphosate (3240 g ae ha-1), glyphosate + 2.4-D (1080 + 1005 g ae ha-1), glyphosate + saflufenacil (1080 + 49 g ae/ai ha-1), paraquat (400 g ai ha-1), diquat (400 g ai ha-1), ammonium glufosinate (600 g ai ha-1), and control (without application). These treatments were applied to plants with a maximum of 5 cm; plants between 6 and 15 cm; and plants between 16 and 25 cm. The results showed that glyphosate did not control weeds, regardless of rate. With the exception of 2,4-D, which needs complementation with sequential application of another contact herbicide, all alternatives were viable for the control of Conyza spp. plants with a maximum height of 5 cm.