When growing potatoes, the main focus of gardeners is on the formation of healthy and large tubers. This criterion ensures a quality crop. Potato tops do not have the same value, but are used in traditional medicine for recipes and for pest control in the garden. But by its appearance, one can judge the condition of the tubers and the entire plant as a whole.
Gardeners often notice that the potato tops are drying or turning black in the beds.
At the end of the growing season, before harvesting, the leaves still begin to dry out. But if this happens much earlier, then the reason for the appearance of black tops is the presence of a disease. Luscious green foliage seems to be replaced, it becomes dry and turns black.
What potato diseases cause this symptom and what to do to save the crop?
Reasons for the appearance of black tops
Most often, such changes with potato tops occur when the bushes are affected by late blight.
Almost all regions are susceptible to the spread of this disease in garden beds. The defeat affects not only the leaves, but all parts of the plant. Therefore, the struggle takes a lot of time and effort. It is better to prevent late blight in the garden than to fight it. It belongs to fungal diseases that spread at high speed. This is its greatest danger. If measures are not taken in time, then the fungus will infect all plantings. In addition to the fact that the tops of potatoes affected by late blight turns black, its tubers rot strongly during storage.
How does a formidable disease manifest on potato tops? At the onset of the disease, the leaves are covered with small brown spots, which then turn brown and turn dark brown. The affected foliage dries and crumbles. Why is potato affected by late blight?
- uncleaned plant residues;
- planting material infected with a fungus;
- violation of the requirements of agricultural technology when growing potatoes.
The more potatoes are planted, the more difficult it is to stop the spread of the disease in which the tops turn black. The most favorable time for the beginning of the spread of late blight is the moment of flowering of the bush. Although the timing of the appearance of the phytopathogenic fungus depends on weather fluctuations. It spreads very quickly during humid, warm days - these are optimal conditions for the development of the disease.
First of all, lesions are noticeable on old potato varieties, which experienced gardeners cherish. They do not always have increased resistance to late blight. Then the disease spreads to other types of potatoes on the site.
The defeat of late blight in potatoes begins with the tops. The leaves seem to be burnt, quickly turn black and dry. A strong degree of damage leads to the death of the entire bush. With watering or rain, pathogenic microflora with water droplets is transferred to the tubers. Their growth stops, then they begin to rot. The danger of late blight also lies in the fact that it entails the occurrence of other diseases in potatoes. The immunity of plants is reduced, they easily succumb to other fungal infections or wet rot.
At high humidity and an air temperature of at least 15 ° C, late blight develops very rapidly, and can hit plantings in a matter of hours. This happens especially quickly during budding and flowering of potatoes.
Attention! Massive defeat is noted in early maturing varieties that fall under ideal weather conditions for the spread of the insidious fungus.
Another reason for the spread of the disease and the appearance of black leaves on potato bushes is a violation of cultivation techniques.
Among the main mistakes of gardeners, it is necessary to highlight:
- Shelter of dug potato tubers with tops. If the leaves are affected, then the disease quickly spreads to the tubers.
- Failure to comply with the harvest time. Early varieties are tried to be dug up later, so that the rind becomes denser. But at this time the autumn rains are already beginning. The water droplets wash away the spores of the fungus and carry them into the soil. The tubers are infected.
Potato tops can turn black when affected by another fungal disease - "black leg". In this case, the factors of the disease will be high humidity and low air temperature. The soil becomes damp and cold, causing the blackleg to spread rapidly.
How to keep potato tops green
The best way is prevention and compliance with all the requirements of agricultural technology. If you nevertheless allowed the spread of late blight on a potato bed, then:
- Change the planting material. Young shoots from infected tubers will already show signs of disease.
- Change where you plant your potatoes. In contaminated soil, even healthy tubers will immediately become ill. But if the beds are well ventilated and other conditions for the development of the fungus are not allowed, then mass destruction can be avoided.
Preventive measures will be:
- liming acidic soil;
- compliance with crop rotation;
- sowing green manure;
- isolation of potato ridges from planting tomatoes, eggplants, physalis or peppers;
- selection of varieties resistant to late blight;
- competent application of fertilizers and wood ash when planting;
- spraying the bushes with copper-containing compounds 2 weeks after germination;
- spraying tops before the moment of budding with preparations "Hom", "Oksikhom".
What to do if the potato tops are already blackened
In this case, it is necessary to carry out a rhythmic spraying of the bushes with Bordeaux liquid, copper chloride with an interval of 7-10 days.
The main focus is on the leaves of the plant, which are treated on both sides. The heavily blackened bush is destroyed.
In addition, all affected tops must be mowed and burned a week before harvest. The harvested tubers are provided with good aeration and air temperature plus 10 ° C - 18 ° C. After 3 weeks, repeat the crop bulkhead.
It is quite possible to prevent late blight on your site. Therefore, pay enough attention to preventive measures and your potato tops will be saved from blackening.