Characteristics and mechanism of flying anti-agent

First, the necessity of using agricultural spray additives

As we all know, the most direct way to achieve excellent plant protection is to increase the amount of crops per unit area such as crops and targets (worms, diseases, grasses). In the actual spraying operation, due to the meteorological conditions, the liquid chemical system, and the physiological and biochemical composition of the crops and targets, the problem of loss and loss of the liquid droplets may occur. The main performance of the loss is the transfer of the liquid medicine to the non-target area. The main performance of the loss is evaporation, showering, and falling from the target. In order to achieve the effect of prevention and control, we generally increase the amount of medicine and the amount of water, which is also an important reason for the low utilization rate of pesticides in China. The increase in the amount of unnecessary liquids increases the amount of investment in agricultural inputs and causes accumulation (contamination) of the environment, and at the same time affects the safety of crops (drugs) and the final agricultural products (crop residues).

In order to change the loss and loss, one way is to improve the spray device and operating conditions, and the other way is to add a spray aid to the liquid, and to improve the impact deposition efficiency of the droplet and the target by adjusting the physical and chemical properties of the liquid. To improve the loss and loss in the natural environment, so as to increase the amount of drug per unit area.

The agricultural spray auxiliaries are auxiliaries added to the medicinal liquid during the spraying of the pesticide, and are also called barrel mixing auxiliaries. Spray auxiliaries mainly play the following effects: 1. Improve the wetting of the liquid in the target; 2. Improve the evaporation rate of the liquid; 3. Improve the permeability and conductivity of the liquid; 4. Improve the liquid The uniformity of the distribution of the droplets on the target; 5, increase the safety of the pesticide to the crop; 6, increase the compatibility of the pesticide mixture; 7, reduce the drift of the pesticide droplets.

From the above we can understand: 1, the use of tank mixing additives in spraying is a necessary means to improve the effective utilization of pesticides; 2, fly-proof special additives are one of the tank mixing additives, and the difference between the surface tank mixing additives It is added with a settling agent to prevent the liquid from drifting. 3. A good tank mixing additive should have the above-mentioned various effects as much as possible.

Second, how does the special agent for flying defense prevent drifting?

Many people think that the anti-floating effect of the sedimentation agent changes the density of the liquid medicine and makes the fog drop heavy and sinks. This is actually a big misunderstanding. First of all, we must understand two basic concepts in the spray: the diameter of the droplets of the liquid and the amount of the solution.

According to the diameter of the droplets, we can divide the droplets sprayed by different application instruments into coarse fog, medium fog, fine fog and very fine fog. The characteristics of coarse droplets are that they can settle to the front of the target quickly, and it is not easy to drift and evaporate with the wind, but the adhesion is poor. It is easy to bounce and roll off after touching the target, causing a large amount of pesticide loss and polluting the environment; characteristics of fine droplets The coverage of the target is even and detailed, and it can enter the part where the large mist is not easy to settle with the airflow. The adhesion on the target is strong and it is not easy to be lost, but it is very easy to evaporate and lose, causing environmental pollution or phytotoxicity, less than 80um. The droplets can even drift ten kilometers, and developed countries have strict legal regulations for low-volume sprays.

Spraying with a coarse mist requires a large amount of application, and spraying with a fine mist requires a low-volume or ultra-low-volume spray. The characteristics of our plant protection drones are that the amount of water is small, and the amount of application liquid per mu is about 1-5 liters. It is a low-volume or ultra-low-volume spray. The droplets are 50-150um, which is very likely to cause drift. The direct impact is The droplets do not act accurately on the target area, causing the leakage to affect the efficacy; the second is that the drift will cause heavy spray or accidental spray, which will cause phytotoxicity on non-target crops.

The core technical point of anti-floating anti-floating agent is to increase the particle size of the originally sprayed fine droplets to a large particle size of 150-250um by adding an auxiliary agent to the liquid medicine under a limited spray device (aircraft). Increasing the proportion of large droplets, that is, retaining the advantages of low-volume spray, effectively solves the weakness of drift and evaporation, thereby improving spray effect and safety.

Third, the characteristics and efficacy of vegetable oil spray additives

The vegetable oil spray aid is a spray aid which is processed by using vegetable oil (or esterification) as a raw material, and has various functions of the spray aid described above.

1. Adjusting the particle size spectrum of the droplet by adjusting the viscosity of the liquid and reducing the surface tension, increasing the particle size of the droplet and the proportion of large droplets, reducing the number of droplets that are easy to drift, thereby improving the utilization of the liquid. Rate, avoiding heavy spray, leaking spray and phytotoxicity caused by drift, avoiding pollution to the environment and impact on non-target organisms;

2. Since the raw materials are completely derived from the plants themselves, they have a very good affinity with the plant leaves, reducing the contact angle between the droplets and the foliage, and expanding the coverage area of ​​the droplets on the foliage. Good wettability increases the amount of drug solution attached to the leaves of the plant and increases the amount of drug per unit of leaf;

3. Improve the physical and chemical properties of the target wax layer, enhance the waxy fluidity and increase the partial waxy dissolution, thereby adjusting the permeability to increase the absorption and conduction of the liquid;

4. The oily matrix has stronger adhesion, that is, the fog droplet spectrum is improved, and the evaporation and rainwater resistance are improved;

5, increase the efficacy of the drug, reduce costs, can achieve the effect of reducing the amount of synergy, the drug effect is stable;

6. The source of plant extracts is environmentally friendly and can be decomposed by plants and soil microorganisms, which is conducive to environmental protection.

7. For areas with high temperature and drought, such as the northwest, it is impossible to absorb liquid medicine when the water hole of the crop is closed at high temperature. Other spray auxiliaries have no affinity with plants, destroying the epidermis of plants through physical action, reducing the immune function of plants, and not increasing the effect of the drug, but causing the invasion of pathogenic bacteria to induce diseases. The affinity of vegetable oil additives and crops allows the liquid to pass through the epidermis wax layer under high temperature conditions and enter the plant for symplast and non-conformity conduction, which is effective and increases crop safety. .

Excellent vegetable oil additives must use stable components. At present, some vegetable oil additives use low-quality materials such as waste oil and biodiesel, which cannot achieve excellent results. We recommend the use of a constant process vegetable oil (or esterification), in which the unsaturated fatty acid carbon eighteen content of more than 65%, the right amount of total tocopherol, can guarantee excellent results.