At present, the use of fungicides is an economical and effective method to prevent and control plant diseases. The role of fungicides in increasing agricultural production has been increasingly recognized by farmers. Do you know what issues should be paid attention to when using fungicides?
1. Use concentration
When spraying with liquid, it is often necessary to prepare or dilute the agent with water to an appropriate concentration. Too high concentration will cause phytotoxicity and waste, and too low concentration will be ineffective. For some non-wettable or difficult to wet powders, water should be added first For a little, adjust the powder into a paste, and then add water to prepare, or you can add some wetting agent during the preparation.
2. Spraying time
If the spraying time is too early, it will cause waste or reduce the control effect. If it is too late, a large number of pathogens have invaded the host. Even if the systemic therapeutic agent is sprayed, the effect will not be great. Spray the medicine for protection when there is no illness or just after the illness.
3. Number of sprays
The number of sprays is mainly determined according to the length of the residual effect of the medicament and meteorological conditions. Generally, spray once every 10 to 15 days for a total of 2 to 3 sprays. Replenishing sprays after rain should consider the cost and save the medication.
4. Spraying quality
The spraying amount should be appropriate. If it is too small, all parts of the plant will not be carefully protected, and too much will be wasted or even cause phytotoxicity. Spraying requires fine mist and uniform spraying. The parts that should be protected include the front and the leaves of the plant. Spray to the opposite side.
5. The problem of phytotoxicity
There are many reasons for spraying to cause phytotoxicity to plants. The more water-soluble medicament is prone to phytotoxicity, and the sensitivity of different crops to the medicament is also different. For example, Bordeaux mixture generally does not cause phytotoxicity, but it is also sensitive to copper. Can produce phytotoxicity.
6. How to mix
Generally, pesticides that are easy to decompose and become invalid when encountered with alkaline substances cannot be mixed with alkaline substances. A few pesticides have a synergistic effect after being mixed.
7. Drug resistance issues
Long-term use of a single agent will cause the pathogen to develop resistance and make the agent used ineffective. To avoid this problem, different types of medicaments can be used alternately, or a systemic bactericide can be mixed with traditional bactericidal agents.