How Herbicide Resistance Develops in Plants

Understanding mode and site of action of herbicides is fundamental to effective weed management and agricultural practices. Herbicides are chemical substances specifically designed to control or eliminate unwanted plants. Herbicide resistance occurs when repeated exposure to the same herbicide allows resistant plants to survive and reproduce. By diversifying the selection and rotation of herbicides with different modes of action, we can reduce the risk of resistance development. Knowing the specific mode of action of each herbicide helps us select a variety of herbicides that target different physiological processes in weeds.

Mode of Action

The mode of action refers to the specific biochemical process or target within the plant that the herbicide interacts with, disrupting vital physiological functions. This interaction may occur at the molecular level, affecting enzymes, proteins, or other essential components.

Site of Action

The site of action refers to the specific location or cellular target within the plant where the herbicide exerts its effects. By understanding both the mode and site of action, applicators and agronomists develop targeted herbicide strategies that optimize weed control while minimizing environmental impact and reducing the risk of resistance development, which is instrumental in shaping sustainable and efficient weed management practices in commercial, utility, agriculture, forestry, and other sectors.

Efficient Weed Management

1. Auxin-like herbicides, including 2,4-D, aminocyclopyrachlor, chlorpyralid, dicamba, and triclopyr, disrupt plant growth and development by mimicking the natural plant hormone auxin.

2. Amino acid synthesis inhibitors, such as aminopyralid, chlorsulfuron, imazapic, imazapyr, metsulfuron, picloram, and rimsulfuron, interfere with essential amino acid production, hindering protein synthesis and inhibiting plant growth.

3. Photosystem inhibitors, including bromacil, diuron, methyl simazine, and sulfentrazone, disrupt the photosynthesis process in plants, leading to a decrease in energy production and eventual plant death.

Soil Active Industrial Herbicides

4. Soil-applied herbicides like bromacil, hexazinone, and tebuthiuron target the soil to inhibit plant growth and prevent germination.

5. Cell division disruptors, such as oryzalin, pendimethalin, and prodiamine, interfere with proper cell division in plants, resulting in stunted growth and the death of germinating seeds and young plants.

6. Other modes of action inhibit EPSP synthase, norflurazon, which inhibits carotenoid synthesis, pramitol, which affects cell division and respiration, saflufenacil, which disrupts cell membranes, sulfometuron methyl, which inhibits acetolactate synthase, and topramezone, which inhibits 4-hydroxyphenylpyruvate dioxygenase.

Understanding the different modes of action of herbicides is crucial in preventing herbicide resistance. This approach ensures that even if resistance to one herbicide develops, other herbicides with different modes of action can still effectively control resistant weed populations. By using a strategic and integrated approach that considers the modes of action, we can better manage weeds and preserve the long-term efficacy of herbicides.

Combating Herbicide Resistance in Commercial Weed Control

A Key Challenge in Commercial Vegetation Management

As the commercial real estate industry continues to evolve, property managers and landscaping professionals face a growing and complex challenge: herbicide resistance. The widespread use of herbicides has led to the emergence of resistant weed populations, posing significant risks to landscape maintenance and vegetation control. This article provides comprehensive insights into herbicide resistance, its implications, and proactive strategies for addressing this issue. While mentioning VegClear's services briefly, our focus is to offer authoritative knowledge rather than promoting a specific brand.

The Rising Challenge of Herbicide Resistance in Commercial Vegetation Control

Herbicides have long been a vital tool for managing unwanted vegetation in commercial landscapes. However, the repetitive and indiscriminate use of herbicides has contributed to the development of herbicide-resistant weeds. These resilient plant populations can survive and reproduce despite herbicide applications, diminishing the effectiveness of traditional weed control methods.

Implications for Commercial Real Estate Managers and Owners of Industrial Property

Herbicide resistance has significant implications for commercial real estate owners and property managers. Uncontrolled weeds not only compromise the aesthetic appeal of properties but also compete with desired vegetation, compromise drainage systems, and potentially harbor pests and allergens. Moreover, the need for more frequent and intensive herbicide applications to control resistant weeds can increase operational costs and pose environmental risks.

Mechanisms of Herbicide Resistance

To effectively combat herbicide resistance, it is crucial to understand the underlying mechanisms. There are two primary mechanisms: target-site resistance and non-target-site resistance.

1. Target-site resistance occurs when genetic mutations in weeds alter the herbicide's target site, rendering it ineffective in binding and controlling the weed population.

2. Non-target-site resistance arises when weeds develop enzymatic systems to metabolize or detoxify herbicides, enabling their survival despite exposure.

PROACTIVE STRATEGIES FOR EFFECTIVE VEGETATION MANAGEMENT

To mitigate herbicide resistance, adopting proactive strategies is essential. Here are key approaches for commercial vegetation control:

INTEGRATED VEGETATION MANAGEMENT (IVM)

Implementing a comprehensive IVM approach is crucial. It combines mechanical control, cultural practices, biological controls, and targeted herbicide applications to reduce reliance on herbicides and prevent resistance development.

DIVERSIFICATION OF HERBICIDES

Rotating and alternating herbicides with different modes of action helps prevent resistance emergence. Utilizing a mix of herbicides with varying biochemical properties enables effective targeting of different weed species and minimizes resistance risks.

MONITORING AND EARLY INTERVENTION

Regular landscape monitoring and early intervention are vital in managing resistant weeds. Identifying and treating resistant populations at their early stages prevents further spread and reduces the need for extensive herbicide applications.

EDUCATION AND TRAINING

Providing proper education and training to property managers, landscaping professionals, and maintenance staff is crucial. Training on herbicide resistance, integrated vegetation management, and correct herbicide usage empowers them to make informed decisions, adopt sustainable practices, and minimize resistance risks.

Herbicide resistance presents a significant challenge for commercial vegetation management, impacting property aesthetics, functionality, and long-term value. By understanding the mechanisms of resistance and implementing proactive strategies such as integrated vegetation management and herbicide diversification, property managers can effectively manage this issue. It is crucial to consider various approaches, consult with professionals, and customize strategies based on specific landscapes and needs. By adopting authoritative practices and staying informed, the commercial real estate industry can proactively address herbicide resistance, ensuring well-maintained and thriving properties for the future.

Download our field reference mixing chart here: VegClear Herbicide Mixing Guide