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When growing potatoes, gardeners focus on the formation of healthy and large tubers. This criterion ensures a quality harvest. Potato tops do not have the same value, but are used in traditional medicine in the preparation of recipes and for pest control in the garden. But by its appearance, one can judge the condition of the tubers and the whole plant as a whole.
Often, gardeners notice that potato tops dry or blacken 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 cause of the appearance of black tops is the presence of a disease. Juicy green foliage seems to be replaced, it becomes dried up and turns black.
What potato diseases cause this symptom and what can be done to save the crop?
Reasons for the appearance of black tops
Most often, such changes occur with potato tops when the bushes are affected by late blight.
Almost all regions are prone to the spread of this disease in garden beds. The lesion affects not only the leaves, but also all parts of the plant. Therefore, the struggle takes a lot of time and effort. Late blight in the garden is better to prevent than to fight it. It refers to fungal diseases that spread at high speed. This is his greatest danger. If measures are not taken in time, then the fungus will affect all plantings. In addition to the fact that the tops of potatoes affected by phytophthora become black, its tubers rot heavily during storage.
How does a formidable disease manifest itself on potato tops? At the beginning of the disease, the leaves are covered with small brown spots, which then turn brown and turn dark brown. The affected tops dry and crumble. Why are potatoes affected by late blight?
The source of the disease are:
- not harvested plant residues;
- planting material infected with a fungus;
- violation of the requirements of agricultural technology in the cultivation of 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 considered to be the moment of flowering of the bush. Although the timing of the appearance of a phytopathogenic fungus depends on weather fluctuations. Very rapid spread occurs during the period of humid warm days – these are optimal conditions for the development of the disease.
First of all, lesions are noticeable on old varieties of potatoes, which are valued by experienced gardeners. They do not always have increased resistance to late blight. The disease then spreads to other types of potatoes in the area.
The defeat of late blight in potatoes begins with tops. The leaves seem burned, quickly turn black and dry. A severe degree of damage leads to the death of the entire bush. When watering or raining, pathogenic microflora with drops of water 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 air temperature not lower than 15 ° C, late blight develops very rapidly, and can hit plantings in a matter of hours. This happens especially quickly during the budding and flowering of potatoes.
Another reason for the spread of the disease and the appearance of black leaves on potato bushes is violation of agrotechnics of cultivation.
Among the main mistakes gardeners need to highlight:
- Shelter of dug out potato tubers with tops. If the leaves are affected, then the disease quickly passes to the tubers.
- Failure to meet harvest time. They try to dig up early varieties later so that the peel becomes denser. But at this time, the autumn rains are already beginning. Drops of water wash off the spores of the fungus and transfer them to the soil. Tuber infection occurs.
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, which leads to the rapid spread of the “black leg”.
How to keep potato greens
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 garden, then:
- Change planting material. Young shoots from infected tubers will already show signs of the disease.
- Change the place of planting potatoes. On contaminated soil, even healthy tubers will immediately fall ill. But if the beds are well ventilated and other conditions for the development of the fungus are not allowed, then mass damage can be avoided.
Preventive measures will be:
- liming of acidic soil;
- observance of crop rotation;
- sowing green manure;
- isolation of potato ridges from planting tomatoes, eggplants, physalis or peppers;
- selection of varieties resistant to phytophthora;
- competent application of fertilizers and wood ash during planting;
- spraying the bushes with copper-containing compounds 2 weeks after germination;
- spraying the tops before the moment of budding with the preparations “Hom”, “Oksih”.
What to do if the tops of potatoes have already turned black
In this case, it is necessary to carry out rhythmic spraying of the bushes with Bordeaux mixture, copper oxychloride with an interval of 7-10 days.
The main attention is paid to the leaves of the plant, which are processed on both sides. A heavily blackened bush is destroyed.
In addition, it is necessary to mow and burn all affected tops a week before harvesting. Harvested tubers are provided with good aeration and air temperature plus 10 ° C – 18 ° C. After 3 weeks, the bulkhead of the crop is repeated.
It is quite possible to prevent late blight from entering your site. Therefore, pay enough attention to preventive measures and your potato tops will be saved from blackening.
