The causative agent of late blight is very tenacious. In contaminated soil, spores can wait 5-7 years for favorable conditions for germination. Therefore, the main prevention of the disease is the observance of crop rotation - a useful, but not always effective procedure. It should be understood that phytophthora spores are carried by the wind, rain (melt) waters and small rodents. In addition, the pathogen remains on the tops, fruits and tubers remaining after harvest. If the contaminated waste is not immediately burned, the pathogen will continue to exist even in the compost pit. The risk of spreading the fungus in this case remains high.
Unfortunately, it is extremely difficult to completely get rid of late blight. I would even say that it is almost impossible. However, to reduce the chances of spreading the disease, the fungus must be deprived of its nutrient medium. To do this, remove all plant residues from the garden (field), such as tops, tubers and infected fruits. The collected waste must be incinerated immediately. Particular attention should be paid to places where plants with clear signs of damage were previously seen. In order not to lose such foci on empty land, sticks can be stuck next to diseased crops during the season.
After the soil is cleared of plant waste, it should be treated with 1% copper sulfate solution or 2% Bordeaux mixture solution. Watering is carried out from a watering can, 1 liter per 1 m² of contaminated soil.
For prevention purposes, the soil after potatoes, tomatoes, eggplants, peppers and other crops suffering from this disease should be treated with a 0.3% solution of copper sulfate. The consumption of the drug remains the same.
Soil tillage against late blight is not a substitute for crop rotation. The crop rotation rules must be followed even after the procedure. At least in order to avoid deficiencies in certain nutrients and trace elements.
Read also on my website -What to plant in the garden before winter: 10 crops
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