For nightshade crops such as potatoes, tomatoes or peppers, the wet and cool weather in summer is a challenge. With prolonged precipitation and night temperatures below 6 ° C, plants can become ill with late blight. Usually this common disease strikes closer to autumn, when the nights get colder, but by this time the crop is already fully ripe. If the summer turned out to be cold and wet from the very beginning, even before the formation of fruits, then there are the risks of an early disease and a complete loss of yield. How to detect the disease in time and take the necessary urgent measures, we will tell you in order.
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How to understand that potatoes are sick
Phytophthora appears as single black spots on the leaves, while the lower shoots on the bush can turn yellow and die off. With heavy, prolonged rains, the disease spreads quickly and very soon spreads to the tubers. At first, the disease does not completely affect all plantings, but individual zones in places that are worse blown by the wind, for example, behind a house or in lowlands.
When the first signs of late blight appear, the ground part of the potato must be treated with a fungicide. In the case when wet cold weather is established from the beginning of summer, it is better to immediately carry out preventive spraying with drugs, before spots appear on the leaves.
What drugs can be used for phytophthora
For the prevention of late blight, biological fungicides can be used, but it should be remembered that in heavy rains, the drug is quickly washed off the leaves.
Processing scheme:
- Before planting, the beds must be treated with a solution of a biological product, such as Trichocin.
- After the tubers begin to sprout, the plantings are periodically sprayed with "Fitosporin-M" or "Abiga-Peak".
- For better adhesion of the drug to the surface of the plant, a special industrial viscous agent is added to the solution to protect against washing off the drugs when spraying, or just liquid soap.
- You can use folk remedies if there are no signs of the disease.
In adverse weather conditions, chemical fungicides should be used throughout the summer:
- The planting material is treated with a protective chemical, for example, Prestige. It will not only prevent phytophthora from developing, but will also save you from the invasion of the wireworm.
- During the growth and maturation of tubers, the tops are sprayed with preparations "HOM", "Profit Gold" or copper sulfate.
Choosing the right potato variety
Most modern potato varieties are resistant to late blight. But if you use part of the crop as planting material year after year, then over time, the internal protective properties of the culture weaken and the risks of late blight increase. In order not to risk, you should buy and plant new planting material every two or three years, and you will not have to spend the whole summer fighting diseases or even being left without a crop.
To choose the right variety of root crops for planting, you need to check for information on resistance to late blight - this should be indicated on the package with seed potatoes. But you should not completely rely only on the variety if your site does not have a very good microclimate and soil quality.
Of the varieties that are resistant to late blight proven by the experience of many summer residents, the following can be distinguished:
- Spring;
- Nevsky;
- Inspiration;
- Red Scarlet;
- Luck.
The tops are completely black - what to do?
If, nevertheless, the moment was missed, and the tops turned black, then the plant stops developing, and the growth of fruits stops. In addition, if left in the soil, tubers can quickly rot.
To stop the further spread of the disease, several rules must be followed:
- Cut off the blackened tops, and after 5-7 days dig up the potatoes.
- Potato residues affected by the disease must be removed from the beds and disinfected with a solution of copper sulfate (200 g per bucket of water) or urea (700 g per bucket of water), and then burned.
- The beds are also treated with fungicide after harvesting potatoes.
- Dug out tubers without visible disease damage are dried and stored.
In order not to lose the potato crop due to late blight disease, it is necessary to thoroughly treat the soil with fungicidal during planting preparations, and then carefully monitor the weather and the condition of the plants and respond in a timely manner to any color changes tops. A correctly selected variety and regular renewal of planting material will avoid unnecessary worries and the use of chemicals in the struggle for the harvest.
Do you know why potato tops turn black?
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