Instructions for the preparation of working solutions of plant protection products

Very often after using one or another plant protection product you notice its low efficiency and, as a rule, the first thing that comes to mind is the low quality of the product or its counterfeit. But very often the reasons are completely different.

Effect of water quality on pesticides.

Water in the working solution can be:

1. Hard (rigid) or soft (depending on the content of calcium and magnesium, carbonate ions).

Calcium and magnesium cations in water can bind to negatively charged particles of herbicide compounds and lead to decreased efficiency. This problem can be solved by adding ammonium sulfate to the solution.

2. Turbid (contain dissolved organic matter, soil, solids) or clear

Water contaminated with organic matter (silt, algae) can reduce the effect of herbicides by binding the active ingredients. This is not true for all herbicides. For example, some herbicides (glyphosates and paraquats) have a high organic carbon absorption coefficient and easily bind to organic particles in the working solution and, therefore, cannot be absorbed by plant leaves. At the same time, herbicides with a low organic carbon absorption coefficient are not as susceptible to the effects of water pollution (dicamba, bentazone, 2,4-D, sethoxydim). Therefore, you need to be sure of the purity of the water used to prepare herbicide solutions. If the water is cloudy, it is advisable to find another source.

3. Water can be:

– Acidic (pH less than 7)

– Neutral (pH=7)

– Alkaline (pH over 7)

Using high pH water (pH 8 or higher) for spraying can cause some herbicides to degrade through alkaline hydrolysis. Alkaline hydrolysis is the breakdown of complex pesticide molecules into simpler particles in an aqueous environment. These simpler particles are often not absorbed sufficiently by weeds and become inert.

The solution to this problem is to add substances that lower the pH of the working solution.

The order of mixing pesticides when preparing tank mixtures

Pesticide formulations

Chemical and physical properties of active substances, such as solubility in various solvents, tendency to degradation, melting point, acidity or alkalinity, are often the reason for the production of a particular formulation of the product. The formulations of pesticides used in Ukraine are as follows:

Pesticide Codification System

(according to the order of 02.06.2011 No. 187 “On approval of the List of codes (designations of formulations) for technical products and pesticide preparations of the international coding system)

Possible interactions and compatibility of pesticides:

— Additional effects – the same effect as when using each pesticide separately (1+1=2).

— Synergism is a greater effect than the effect of using each pesticide separately (1 + 1 = 4)

— Antagonism m — obtaining less effect when using substances together than when using each pesticide separately (1 + 1 = 1).

— Enhancement is a type of interaction (not between two pesticides) that occurs when pesticides are mixed with additives that provide a greater effect than when the pesticide is applied alone, such as when adjuvants or fertilizers are added.

Mixing pesticides in a sprayer:

1. Always read the label and use pesticides according to the directions on the label.

Pay attention to the recommendations regarding the order of mixing. Do not ignore the steps described in the instructions – this is vital to get the best results from your crop protection products.

2. stir pesticides thoroughly

Keep the stirrer running continuously to ensure thorough mixing and uniform distribution of the product.

3. Follow the order of mixing the preparations, stirring them only one at a time.

Remember not to mix pesticides together immediately! Different liquid products, when poured from the canister, react with each other immediately before being diluted in the water tank. This can lead to sedimentation and solidification of concentrates.

4. rule of adding conditioners and adjuvants

Depending on the type of adjuvant you are using, it should be mixed either at the beginning or at the end of the mixing process. Adjuvants that are used to improve compatibility and water conditioners should be added to the mixture first. On the other hand, adjuvants that are used to improve biological effectiveness should be mixed at the end.

The correct mixing order is:

1. Partially fill the sprayer tank with water according to the label recommendations, 2/3 to ¾ of the volume. Turn on the sprayer agitator and continue mixing during the preparation of the working solution and spraying.
2. Add water conditioner (ammonium sulfate).
3. Add fertilizers or micronutrients (solid, liquid).
4. Add preparations in the form of water-soluble powders (WP).
5. Add preparations in the form of water-soluble granules (WG), in the form of granules dispersible in water (WG).
6. Add preparations in the form of suspension concentrates (SC).
7. Add preparations in the form of emulsifiable concentrates (EC).
8. Add preparations in the form of oil dispersions (OD).
9. Add preparations in the form of an emulsion, oil in water (OI) or suspoemulsion (SE).
10. Add preparations in the form of soluble concentrates (SC).
11. Add other adjuvants.
12. Fill the sprayer tank until it is full.

The main signs of pesticide incompatibility:

— Precipitation

— Solid formations

— Stratification of liquids

– Heating the solution

— Formation of a single lump

– Gel formation

Please note this information does not change the instructions on the product label. Always read the complete product label located on the package before opening or using products.