Herbicide efficacy for aquatic Alternanthera philoxeroides management in an early stage of invasion: integrating above‐ground biomass, below‐ground biomass and viable stem fragmentation

Abstract

Summary Alternanthera philoxeroides is a problematic invasive plant in many regions of the world that is difficult to control once naturalised. It poses a threat to agricultural productivity, biodiversity and social amenity values of aquatic environments. Significant research has been conducted internationally, regarding the efficacy of different herbicides for control of A. philoxeroides. However, no studies have looked at key aspects of control for effective management in an early stage of invasion of aquatic environments, hindering eradication and control programmes. This study evaluates the efficacy of herbicides and surfactants on key A. philoxeroides response metrics, including control of above‐ground biomass, below‐ground biomass and production of viable stem fragments. This study concluded that glyphosate (isopropylamine salt) minimises viable stem fragment production post‐herbicide application, compared with imazapyr and metsulfuron, thus reducing the potential for dispersal throughout catchments and waterways. In contrast, imazapyr and metsulfuron provided more effective control than glyphosate for A. philoxeroides growing on exposed embankments. We propose that an effective management strategy for early invasion of aquatic A. philoxeroides, using herbicides, would be to conduct initial applications of glyphosate to control overwater biomass and limit dispersal of viable stem fragments. Once infestations have been forced back to the embankment, imazapyr or metsulfuron treatments will provide longer term control.

Identify potential allelochemicals from Humulus scandens (Lour.) Merr. root extracts that induce allelopathy on Alternanthera philoxeroides (Mart.) Griseb.

“…Three principal means are generally utilized to control the alligator weed, being physical 17 , chemical 18 , 19 and biological removal 20 . Physical methods are mainly to remove invasive plants by manual and mechanical methods; chemical methods are to spray chemical herbicides such as glyphosate to cause plant death; biological methods are mainly to control plant growth by natural enemies, soil animals and soil microorganisms.…”

Pleiotropic Outcomes of Glyphosate Exposure: From Organ Damage to Effects on Inflammation, Cancer, Reproduction and Development

“…Its main function is to eliminate weeds in crops of wheat, canola and soybeans, even though, in wheat crops, it is also used as a desiccant before the harvest [2]. In addition, glyphosate is used in urban areas, in parks and in marine contexts to eliminate aquatic plants [3]. In the mid-1990s the use of glyphosate and GBHs increased rapidly because of the development 2 of 24 of glyphosate-resistant GM crops.…”

Efeitos do herbicida Roundup® em Laguncularia racemosa (L.) C. F. Gaertn (combretaceae)/ Effects of the herbicide Roundup® em Laguncularia racemosa (L.) C. F. Gaertn (combretaceae)

“…Os herbicidas são os agrotóxicos que apresentam maior consumo devido às modernas técnicas de produção, sobretudo com a utilização dos cultivares transgênico (resistentes a herbicidas), e à necessidade crescente de proteção das culturas vegetais da ação de diversas espécies indesejáveis (Lorenzatti et al 2008;Monsanto 2014;Teran et al 2020). Além disso, e em menor intensidade, herbicidas também são aplicados para controlar macrófitas aquáticas em reservatórios de abastecimento, canais de irrigação e para controle de espécies aquáticas invasoras (Gettys et al 2014;Clements et al 2017).…”