Ambrosia sp.: dose-response to glyphosate

Laura Bordignon; Rafael Zella; Flávia Zucco; Ricardo Pazinato; Veronika Lemos da Siva; Antonio Mendes de Oliveira Neto; Naiara Guerra

Autores

Laura Bordignon http://orcid.org/0009-0009-3797-3272
Rafael Zella http://orcid.org/0009-0000-7804-5549
Flávia Zucco http://orcid.org/0009-0009-4388-5578
Ricardo Pazinato http://orcid.org/0009-0001-6894-6412
Veronika Lemos da Siva Universidade Federal de Santa Catarina http://orcid.org/0009-0006-0825-8905
Antonio Mendes de Oliveira Neto http://orcid.org/0000-0002-4616-5594
Naiara Guerra Universidade Federal de Santa Catarina - UFSC Campus Curitibanos

Palavras-chave:

EPSPs-inhibiting herbicide, increasing dose, weed, common ragweed.

Resumo

Background: Farmers have reported difficulty in controlling Ambrosia sp., observing uncontrolled plants in soybean fields even after post-emergence glyphosate application

Objective: The aim of this study was to evaluate the response of Ambrosia sp. to different rates of the herbicide glyphosate.

Methods: The experiment was conducted in duplicate in a greenhouse at the Federal University of Santa Catarina, Curitibanos campus, between September and December 2022, using a completely randomized design with four replications. The treatments consisted of the application of nine increasing rates of the herbicide glyphosate (0; 93.75; 187.5; 375; 750; 1500; 3000; 6000; 12000 g ae ha^-1) when the Ambrosia sp. plants had between 4 to 8 true leaves. The following parameters were evaluated: height; percentage of control; and final above-ground dry matter mass.

Results: The results indicated growth inhibition, resulting in reduced height for rates starting from 1500 g ae ha^-1 in Ambrosia sp. The evaluation of final above-ground dry matter mass showed a reduction between 73 and 95%, depending on the dose applied.

Conclusions: Even the high rates used were not able to achieve excellent control (>90%) of the species.