minnowyy
Member
I am a science communication student and today I would like to discuss some issues about IWM with you, here is an article and factsheet about the latest research written and I look forward to your reading.
Weed Wars： Sustainable Strategies for UK Farms
A silent battle is emerging now and then in the UK's lush green fields. Farmers are battling not only weeds but also an even more resilient opponent: herbicide resistance. The impact of this growing threat is becoming increasingly evident. According to the International Herbicide Resistant Weeds Database, as of 2024, 533 cases of herbicide resistance have been reported globally, with weeds resistant to 21 of the 31 known herbicide loci of action and 168 different herbicides.
Think of it like a game of cat and mouse. You're helping yourself with the latest and greatest herbicides, but there are still some stubborn foes that can't be eradicated from your land, and they're becoming more and more prevalent over time - that's because these weeds develop resistance. Herbicide resistance refers to the heritable ability of a weed to survive and reproduce when exposed to a dose of an agent that is normally effective for control.
If you thought that weed resistance would only develop to chemicals and that constantly changing herbicides would be the answer, weeds may be more intelligent than you think. Research has previously found that as a result of intensive hand weeding of a cultivated rice, it was possible to select for rice mimic weeds that were "resistant" to hand weeding. What this also illustrates is that the effectiveness of any single weed control method for weed management is time-limited and is a resource that will be exhausted.
Integrated Weed Management (IWM) is often misunderstood. Many assume it means complex crop rotations and lower economic benefits. Yet in fact perhaps the opposite is true. Research has already shown that short rotations of high-value crops can lead to high weed densities and the development of herbicide resistance, resulting in very serious economic and yield losses. According to scientists at the University of Sheffield and the conservation charity Zoological Society of London (ZSL), weed resistance to herbicides costs the UK economy an estimated £400 million a year. In addition, the extensive use of herbicides has also caused damage to the ecological environment and human health.
In the long run, Integrated weed management (IWM) is an inevitable choice. It's never too late to switch. Up next, we'll analyse why moving to IWM sooner rather than later can better reduce the long-term costs of managing herbicide resistance.
Varah et al. designed a set of experiments to explore the impact of taking proactive actions on the long-term management costs of weed resistance. Before designing the strategy, the research team categorised the land according to soil type, ryegrass density and resistance in the trial fields—low density, low resistance (LD-LR), low density, high resistance (LD-HR), high density, high resistance (HD-HR).
Subsequently, Varah et al. designed three different crop rotation management strategies to investigate the effect of different management strategies on weed density, crop yield and farm profitability. They were:
MIT (Mitigation): emphasises on diversified crop rotation and non-chemical methods of weed control, but retains a high level of herbicide use.
BAU (Business As Usual): based on current crop rotations and weed management practices commonly used by farmers, with a two-year winter wheat and one-year winter oilseed rape rotation, combined with the use of chemical herbicides.
CWW (Continuous Winter Wheat): grows wheat every year to maximise wheat yields, but does not consider weed management diversification.
After using statistical modelling to predict weed densities under each management strategy, they evaluated the gross profits and yields resulting from each management strategy and associated weed infestation, and then compared them.
Overall, CWW, while providing higher wheat yields each year, is the least economically effective at controlling weed densities. This means that long-term use of CWW strategies will face more severe weed resistance problems, which may ultimately lead to higher management costs and yield losses.
BAU strategy and MIT strategy had different results on different lands. On average, BAU performed best in terms of economic returns and wheat yields, with the highest, but not outstanding, average annual profit, and a small difference with the MIT strategy. The economic performance of both is influenced by many factors, for example, MIT earns more than BAU when the initial resistance is low, and the opposite is true when the initial resistance is high. Including the use of herbicides on different lands also has an impact on economic viability.
However, it is worth noting that the MIT strategy reduced the proportion of fields with economically damaging blackgrass densities in almost all years. In contrast, the BAU strategy leads to higher weed densities and increased resistance in the long term, potentially leading to higher management costs and chemical herbicide inefficiencies in the future.
In summary, on land where blackgrass resistance is not yet an issue (LD-LR), a proactive switch to the MIT strategy is economically feasible and closest to IWM. Using the MIT strategy in LD-LR is the only strategy that reduces herbicide use, and the number of glyphosate applications in the MIT strategy hardly triggers glyphosate resistance - that sounds exciting doesn't it? And the MIT strategy is more environmentally beneficial and favours biodiversity for long term benefits. So in scenarios where BAU offers only a slight financial or production advantage over MIT, we still encourage farmers to choose the MIT approach. In contrast, in fields with high densities of resistant blackgrass (HD-HR), there is a trade-off between meeting wheat production requirements, gross farm profit and avoiding further evolution of resistance.
We strongly recommend a pre-emptive MIT strategy. That is, if you win this “race” against the emergence of blackgrass resistance, you will reap higher economic and environmental benefits. It's a speed contest, but the winning result sounds very tempting, right?
All in all, herbicide resistance has caused huge economic losses and environmental damage globally, and traditional crop management practices are no longer affordable. As stewards of the land, farmers can reduce their reliance on herbicides and decrease the likelihood of developing resistance by integrating crop rotations, using cover crops, and exploring non-chemical weed control methods. We have an opportunity to turn the tide with more diverse and environmentally conscious management strategies. In this silent battle, farmers are fighting not just for themselves, but for the sustainability of the world. Let's stand on our field， and cultivate change.
Weed Wars： Sustainable Strategies for UK Farms
A silent battle is emerging now and then in the UK's lush green fields. Farmers are battling not only weeds but also an even more resilient opponent: herbicide resistance. The impact of this growing threat is becoming increasingly evident. According to the International Herbicide Resistant Weeds Database, as of 2024, 533 cases of herbicide resistance have been reported globally, with weeds resistant to 21 of the 31 known herbicide loci of action and 168 different herbicides.
Think of it like a game of cat and mouse. You're helping yourself with the latest and greatest herbicides, but there are still some stubborn foes that can't be eradicated from your land, and they're becoming more and more prevalent over time - that's because these weeds develop resistance. Herbicide resistance refers to the heritable ability of a weed to survive and reproduce when exposed to a dose of an agent that is normally effective for control.
If you thought that weed resistance would only develop to chemicals and that constantly changing herbicides would be the answer, weeds may be more intelligent than you think. Research has previously found that as a result of intensive hand weeding of a cultivated rice, it was possible to select for rice mimic weeds that were "resistant" to hand weeding. What this also illustrates is that the effectiveness of any single weed control method for weed management is time-limited and is a resource that will be exhausted.
Integrated Weed Management (IWM) is often misunderstood. Many assume it means complex crop rotations and lower economic benefits. Yet in fact perhaps the opposite is true. Research has already shown that short rotations of high-value crops can lead to high weed densities and the development of herbicide resistance, resulting in very serious economic and yield losses. According to scientists at the University of Sheffield and the conservation charity Zoological Society of London (ZSL), weed resistance to herbicides costs the UK economy an estimated £400 million a year. In addition, the extensive use of herbicides has also caused damage to the ecological environment and human health.
In the long run, Integrated weed management (IWM) is an inevitable choice. It's never too late to switch. Up next, we'll analyse why moving to IWM sooner rather than later can better reduce the long-term costs of managing herbicide resistance.
Varah et al. designed a set of experiments to explore the impact of taking proactive actions on the long-term management costs of weed resistance. Before designing the strategy, the research team categorised the land according to soil type, ryegrass density and resistance in the trial fields—low density, low resistance (LD-LR), low density, high resistance (LD-HR), high density, high resistance (HD-HR).
Subsequently, Varah et al. designed three different crop rotation management strategies to investigate the effect of different management strategies on weed density, crop yield and farm profitability. They were:
MIT (Mitigation): emphasises on diversified crop rotation and non-chemical methods of weed control, but retains a high level of herbicide use.
BAU (Business As Usual): based on current crop rotations and weed management practices commonly used by farmers, with a two-year winter wheat and one-year winter oilseed rape rotation, combined with the use of chemical herbicides.
CWW (Continuous Winter Wheat): grows wheat every year to maximise wheat yields, but does not consider weed management diversification.
After using statistical modelling to predict weed densities under each management strategy, they evaluated the gross profits and yields resulting from each management strategy and associated weed infestation, and then compared them.
Overall, CWW, while providing higher wheat yields each year, is the least economically effective at controlling weed densities. This means that long-term use of CWW strategies will face more severe weed resistance problems, which may ultimately lead to higher management costs and yield losses.
BAU strategy and MIT strategy had different results on different lands. On average, BAU performed best in terms of economic returns and wheat yields, with the highest, but not outstanding, average annual profit, and a small difference with the MIT strategy. The economic performance of both is influenced by many factors, for example, MIT earns more than BAU when the initial resistance is low, and the opposite is true when the initial resistance is high. Including the use of herbicides on different lands also has an impact on economic viability.
However, it is worth noting that the MIT strategy reduced the proportion of fields with economically damaging blackgrass densities in almost all years. In contrast, the BAU strategy leads to higher weed densities and increased resistance in the long term, potentially leading to higher management costs and chemical herbicide inefficiencies in the future.
In summary, on land where blackgrass resistance is not yet an issue (LD-LR), a proactive switch to the MIT strategy is economically feasible and closest to IWM. Using the MIT strategy in LD-LR is the only strategy that reduces herbicide use, and the number of glyphosate applications in the MIT strategy hardly triggers glyphosate resistance - that sounds exciting doesn't it? And the MIT strategy is more environmentally beneficial and favours biodiversity for long term benefits. So in scenarios where BAU offers only a slight financial or production advantage over MIT, we still encourage farmers to choose the MIT approach. In contrast, in fields with high densities of resistant blackgrass (HD-HR), there is a trade-off between meeting wheat production requirements, gross farm profit and avoiding further evolution of resistance.
We strongly recommend a pre-emptive MIT strategy. That is, if you win this “race” against the emergence of blackgrass resistance, you will reap higher economic and environmental benefits. It's a speed contest, but the winning result sounds very tempting, right?
All in all, herbicide resistance has caused huge economic losses and environmental damage globally, and traditional crop management practices are no longer affordable. As stewards of the land, farmers can reduce their reliance on herbicides and decrease the likelihood of developing resistance by integrating crop rotations, using cover crops, and exploring non-chemical weed control methods. We have an opportunity to turn the tide with more diverse and environmentally conscious management strategies. In this silent battle, farmers are fighting not just for themselves, but for the sustainability of the world. Let's stand on our field， and cultivate change.
