Survey of major weed problems, management practices and herbicide use in extensive row crops from Argentina

Abstract:

Background:

Weeds pose a significant challenge to Argentine crops, leading to herbicide resistance and environmental concerns.

Objective:

To identify key weed problems, assess management practices, and herbicide use.

Methods:

A web-based survey system, with closed questions, was distributed from March to August 2020 among 147 agricultural stakeholders related to soybean, corn, wheat, and sunflower crops in Argentina.

Results:

Notable troublesome weeds included Conyza bonariensis (L.) Cronq., Digitaria sanguinalis (L.) Scop., Eleusine indica (L.) Gaertn., Amaranthus hybridus L., and Sorghum halepense (L.) Pers. Herbicide usage was as follows: 86% used burndown fallow chemical control, 51% adhered to labeled application rates, 40% applied herbicides at the labeled growth stage, and 37% rotated modes of action. Non-chemical controls were also employed, with 67% favoring crop rotation and 36% focused on preventing weed seed production. Glyphosate was the dominant herbicide, employed by over 90% of respondents. For summer crops, frequently used herbicides included paraquat, 2,4-D (80% of respondents), atrazine (60% of respondents), sulfentrazone, flumioxazin, S-metolachlor (60% of respondents), and clethodim (65% of respondents). In winter cereals, 2,4-D, flurochloridone, flumioxazin, and pyroxasulfone were the top choices.

Conclusions:

This survey underscores the high reliance on chemical control in Argentina's major crops. The findings provide crucial insights for regional policy planning, emphasizing the importance of integrating diverse weed management tactics. It also highlights the need for proactive integrated management strategies at the field level to mitigate and prevent weed issues in Argentina, offering a valuable approach for analyzing weed problems in extensive crops worldwide.

Keywords:
Chemical Control; Integrated Weed Management; Problematic Weeds; Spring-Summer Crops; Winter Cereals