Introduction
Agriculture has been one of the oldest and fundamental activities of humanity, allowing the development of civilizations and guaranteeing the feeding of entire populations. Over the years, one of the biggest challenges this sector has faced is the constant threat of pests and diseases that can devastate entire crops in a short time. To combat these threats, different tools have been developed, pesticides being one of the most effective. However, its use has brought debates about its environmental impact, its effectiveness and the possible toxic residues that can be left in food.
This is where adjuvants come into play. These substances, which in many cases go unnoticed in discussions about sustainable agriculture, have proven to be essential to enhance and improve the effectiveness of pesticides, allowing them to use less and obtaining better results. Their role is so crucial that, in some cases, the difference between a successful treatment and an ineffective one lies in the correct use of adjuvants.
This article seeks to explore the nature, function and importance of adjuvants in the world of pesticides, highlighting how these compounds can be the key to a more sustainable and efficient agriculture.
I. What are Adjuvants?
The term "adjuvant" comes from the Latin "coadiuvare", which means to help or assist. In the context of pesticides, adjuvants are substances or mixtures that, although they do not have pesticidal properties per se, improve the efficacy or modify the physical properties of the formulation. Its main purpose is to improve the application, efficiency, and/or adherence of pesticides, allowing them to perform their function optimally.
Main types of adjuvants:
- Surfactants: They are the most common adjuvants. They act by modifying the surface tension of the water, allowing a better dispersion and adherence of the pesticide on the leaves or the target surface. They are often used to improve the wettability of formulations.
- Oils: They include mineral and vegetable oils that improve the penetration of the active ingredient in the plant or pest. They can act as vehicles, taking the active ingredient to more inaccessible places.
- pH regulators: They stabilize or adjust the pH of the pesticide solution, ensuring that the active ingredient remains in an effective chemical form during its application.
- Defoamers: Reduce the formation of foam during the mixing and application of the pesticide, facilitating a more efficient process.
- Stabilizers: Help prevent degradation of the active ingredient under adverse conditions, such as extreme temperatures or ultraviolet light.
The proper use of adjuvants can make a significant difference in the effectiveness of a pesticide treatment. Although they usually represent only a small fraction of the total mix, their impact on product performance can be crucial.
II. Functions and benefits of Adjuvants
Adjuvants play an integral role in optimizing pesticide formulations. Although they do not have intrinsic pesticidal activity, their function is to enhance, modify or improve the efficacy and application characteristics of these products. Its main functions and associated benefits are described below:
Solubility improvement:
Function: Some pesticide active ingredients are poorly soluble in water. Adjuvants can increase its solubility or dispersibility, allowing a homogeneous mixture.
Benefit: Facilitates a uniform application and prevents sedimentation or formation of lumps in the mixture, guaranteeing that the plant or pest receives an effective dose.
Increased Efficiency:
Function: They improve the adherence of the pesticide to the surface of the plant or pest, ensuring that the product is not easily washed away by rain or irrigation.
Benefit: Maximizes the contact time between the pesticide and its target, increasing the chances of treatment success.
Dose reduction:
Function: By improving solubility, adhesion and penetration, the efficiency of the active ingredient is optimized.
Benefit: The same or even better control can be achieved with less amount of pesticide, which translates into economic savings and less environmental impact.
Less environmental impact:
Function: Adjuvants allow a more precise and efficient application, reducing the amount of pesticide that can run off into the soil or bodies of water.
Benefit: Minimizes environmental pollution, protects beneficial fauna and ensures an ecological balance.
Improved penetration:
Function: Some adjuvants, especially oils, facilitate the entry of the pesticide through the cuticle of the plants or exoskeleton of the pests.
Benefit: Increases the effectiveness of the pesticide when reaching more protected or internal areas, such as plant tissues or internal pest systems.
It is clear that adjuvants are not simple "additives". They are essential tools that, when correctly selected and applied, can completely transform the efficiency and sustainability of pesticide treatments. When considering its use, it is essential to remember that the synergy between the adjuvant and the active ingredient of the pesticide is what defines the success of the intervention.
III. How Adjuvants work
To fully understand the crucial role of adjuvants, it is essential to understand how they interact and modify the properties of pesticides. Although the specific actions may vary depending on the type of adjuvant and the pesticide formulation, there are certain fundamental mechanisms that remain constant:
Modification of surface tension:
Explanation: Surfactants, one of the most common adjuvants, reduce the surface tension of solutions. This means that when a surfactant pesticide solution is applied to a surface, it tends to spread more evenly rather than droplet.
Impact: Allows for better coverage of the target plant or surface, ensuring that the active ingredient reaches larger and harder-to-reach areas.
Facilitation of penetration:
Explanation: Some adjuvants act as solubilizers or penetrants, helping the active ingredient to cross natural barriers, such as the cuticle of plants or the exoskeleton of insects.
Impact: This translates into a faster and more effective action of the pesticide, and in some cases, it can allow the pesticide to reach areas where pests or diseases are protected.
Formulation stabilization:
Explanation: Some pesticides can be unstable under certain conditions, degrading or losing effectiveness. Builders can act as stabilizers, preserving the integrity of the active ingredient.
Impact: Ensures that the pesticide maintains its effectiveness during storage and application.
Mix optimization:
Explanation: The adjuvants can act by improving the homogeneity of the mixture, avoiding the formation of lumps or separations and facilitating the preparation and application.
Impact: Allows for a more uniform application and reduces the risk of over or under-dosing in certain areas.
Protection against environmental factors:
Explanation: Environmental conditions, such as ultraviolet light or extreme temperatures, can affect the effectiveness of some pesticides. Certain adjuvants offer protection against these factors.
Impact: Extends the useful life and effectiveness of the pesticide even under adverse conditions.
Adjuvants, by interacting and physicochemically modifying pesticide formulations, become enhancing agents. Its action is not only based on making the pesticide more effective, but also on ensuring that its application is more sustainable and less harmful to the environment.
IV. Considerations to take into account when choosing an Adjuvant
The choice of the appropriate adjuvant can be decisive for the success of the treatment with pesticides. Not all adjuvants are suitable for all applications, and their effectiveness may vary depending on the type of crop, climate, control objective, among other factors. Here are some key considerations to keep in mind:
Pesticide Type:
Explanation: Not all adjuvants are compatible with all pesticides. Some may interfere with the action of the active ingredient or cause mixing problems.
Recommendation: Consult the pesticide manufacturer's recommendations and perform compatibility tests before large-scale application.
Treatment Objective:
Explanation: Depending on whether the objective is to control insects, fungi, weeds, etc., the most appropriate type of adjuvant may vary.
Recommendation: Choose adjuvants that are specifically formulated for the type of treatment being carried out.
Weather conditions:
Explanation: Factors such as humidity, temperature or the presence of rain can influence the effectiveness of the adjuvant.
Recommendation: Select adjuvants that are suitable for the climatic conditions expected during and after the application.
Type of crop:
Explanation: Some crops have thicker cuticles or hairy leaves that can affect pesticide adhesion and penetration.
Recommendation: Opt for adjuvants that are designed to improve penetration in specific crops.
Environmental impact:
Explanation: It is vital to consider the ecological impact of adjuvants, especially if they are applied near water sources or in areas with beneficial fauna.
Recommendation: Prioritize adjuvants with low environmental impact and that are biodegradable.
Efectivity cost:
Explanation: While it is tempting to go for the cheapest adjuvant, it is essential to evaluate its efficacy and long-term benefit.
Recommendation: Analyze the relationship between the cost of the adjuvant and the added value it provides in terms of improved efficacy and reduced pesticide dose.
Choosing the right adjuvant is a process that requires research, testing, and sometimes expert consultation. By devoting time and effort to this choice, not only the success of the treatment, but also the sustainability and safety of the application can be guaranteed.
conclusion
Adjuvants play an essential role in optimizing the use of pesticides in modern agriculture. By modifying physical and chemical properties of the formulations, they improve the dispersion, penetration and stability of pesticides, maximizing their effectiveness. However, choosing the right adjuvant requires careful consideration of factors such as the type of pesticide, the goal of treatment, and environmental conditions. Despite its proven efficacy, there are still challenges, such as pesticide resistance and environmental issues, that need to be addressed. Future prospects in the field of adjuvants lean towards more sustainable, biodegradable and versatile solutions, which are anticipated to be fundamental in the evolution of crop protection.
