The 28th APWSS Conference to be held at Phuket, Thailand during 26 to 29 November 2023           |           Weeds-Journal of the APWSS Vol. 4, Issue 2, 2022

Volume-4 | Issue-2 (July-December) | Year 2022

The Need for Climate-Resilient Integrated Weed Management (CRIWM) under future Climate Change
Adusumilli Narayana Rao and Nimal Chandrasena

KEYWORDS:

Asian-Pacific Region, weeds, climate-resilience, Integrated weed management, IWM, CRIWM

Abstract:

Ensuring future food and nutritional security, while reducing poverty are significant global challenges. This is especially true in the Asian-Pacific region, characterized by rapid population growth, food shortages and landuse changes. The region is already affected by a changing climate with increased periods of droughts and rainfall in some countries. Efforts to increase crop productivity and reduce existing crop yield gaps are critically-important to meet the targeted food and nutritional security goals in the region. This requires identifying and addressing constraints, such as the changes in weed flora and alleviating the negative effects of weed abundance in cropping fields with sustainable technologies. Climate-Resilient Integrated Weed Management (CRIWM) is a new term that has emerged to assist in this effort. CRIWM is an intensely-focused approach that aims to increase crop productivity sustainably, while simultaneously reducing the adverse effects of weeds and greenhouse gas emissions of agricultural practices. CRIWM can be used to re-energize educating all those involved in agriculture to plan for uncertainties in weed management outcomes under a changing climate. The approach requires doing what has been done so far in managing weeds even better. Targeted research must explore new combinations of already well-established methods (such as conservation farming, regenerative agriculture, soil health and cultural weed control practices, as well as biological and chemical weed control) with an eye for options to reduce reliance on any one technique alone. Precision weed control robotics and other ‘climate-smart’ innovations (such as the use of solar-powered equipment) appear crucial in planning for more effective weed management under climate change.

Email

anraojaya1@gmail.com

Address

Consultant Scientist (Weed Science), Hyderabad-500033, India
How may Climate Change affect the activity of Glyphosate on Weeds? Some reflections
Khawar Jabran, Nimal Chandrasena, Taseer Ahmad and Ali Ijaz

KEYWORDS:

Climate change, eCO2, global warming, weeds, crops, glyphosate, herbicidal activity

Abstract:

The evidence of changes in the global climate being felt by all of the bio-physical environments on the Earth is undisputed. Well-established literature, some of which is summarized herein, shows that the climate change effects will modify agro-ecosystems, including the multiple interactions between crops and weeds. From the perspective of weed management, there is compelling evidence that climate change effects will alter the growth of both C3 and C4 weeds and C3 and C4 crops in their interactions in cropping environments. Such responses will not just modify the outcomes of weed-crop competition, but also affect the efficacy of weed management methods, including the performance of herbicides. Glyphosate [N-(phospho-methyl) glycine] is unquestionably the world’s most used and successful herbicide. Published research, over at least three recent decades, indicates that glyphosate’s efficacy and activity on specific weeds may increase or decrease in the wake of elevated atmospheric carbon dioxide (eCO2) concentrations, global warming and associated climate change effects (such as increased or decreased rainfall and droughts). Changed glyphosate activity under climate change has been attributed to several factors. These include modified plant morphology and physiology (e.g., lower number of stomata, increased leaf thickness and modified cuticle permeability, etc.), which affects plant uptake and also changes in translocation of the herbicide to metabolically-active target sites. However, there is also evidence that, under some conditions, glyphosate activity on specific weedy taxa or groups of weeds may not be adversely affected by the dominant climate-modifying factors. In this article, we appraise some of the published evidence on glyphosate and reflect upon those factors and how the growth and vigour of weedy taxa might affect the efficacy of glyphosate, under eCO2 and a warmer global climate. In our view, aside from the broad generalizations, the effects of eCO2 and warming on glyphosate efficacy on major weeds cannot yet be discerned without more directed research.

Email

khawarjabran@gmail.com

Address

Department of Plant Production and Technologies, Nigde Omer Halisdemir University, Turkey
Lantana (Lantana camara L.) biocontrol agents in Australia with possible options for India and Sri Lanka
Nimal Chandrasena and Michael Day

KEYWORDS:

Lantana biocontrol agents, host specificity, invasive, Teleonemia scrupulosa, Uroplata girardi

Abstract:

The focus of this short article is the biocontrol agents of the globally-important species - lantana (Lantana camara L.), which was introduced as an ornamental plant during the 18th and 19th Centuries across continents. Lantana is now naturalized in most continents and causing problems in human-modified landscapes and is also spreading fast into conservation areas and forests. Currently, where it needs to be controlled, a variety of methods are available, which include manual, mechanical and chemical control, as well as fire. However, none of these methods, even when applied in combinations (integrated) have been sufficiently effective on a landscape level or can be sustainably applied to control large and dense infestations. It appears that future lantana management must be oriented towards re-investing in biocontrol simply because it is not feasible to control lantana over the long term using conventional methods. Numerous biocontrol agents have shown considerable promise but have not been well utilized in countries that have increased risks of further spread. Efforts to manage lantana in Australia are still continuing, with a well-developed National framework, an integrated approach and investment in additional biocontrol agents. South-Asian countries, especially India and Sri Lanka, can certainly benefit from Australian experiences in lantana management and R&D investments in biological control. This is especially so since research on host specificity and the effectiveness of agents would have already been conducted. This would require that both countries, and also, possibly some African countries, re-appraise the risks of lantana and make an increased effort at biocontrol to manage those risks, especially in natural ecosystems and conservation areas, heavily disturbed by tourism activities.

Email

nimal.chandrasena@gmail.com

Address

Nature Consulting, 17, Billings Way, Winthrop, WA 6150, Australia