Potatoes are quite vulnerable to various fungi, bacteria and viruses. The appearance of spots on potato tops most often indicates that the crop has been affected by some kind of disease. In order not to lose the harvest, the gardener needs to determine the cause of the spots as quickly as possible and take measures to save the plants.
Macrosporiasis
Typically, signs of this disease can be seen even before the potatoes begin to bloom. Macrosporiasis appears as small brown or gray spots on the tops. As the disease progresses, the tops gradually wither. You can cope with macrosporiosis using Bordeaux mixture or Polycarbacin. For preventative purposes, it is useful to treat the potato field with Bordeaux mixture after the crop has been dug up.
Late blight
This fungal disease is considered one of the main causes of potato crop failure in Russia. Late blight can be identified by brown spots on the tops and drying of the leaves. A white coating can be seen on the back of the leaves. Treatment should begin at the first signs of late blight. It is best to use fungicides, for example Fundazim, Metaxil or copper sulfate. To enhance the effect, you can use folk remedies in the fight for the harvest. For example, wood ash or whey.
Alternaria blight
This fungus first attacks the lower leaves of the potato and then spreads to the entire plant. With Alternaria blight, dark brown spots appear on the leaves, and spots can also be seen on the tubers. Bordeaux mixture and other fungicides will help cope with the fungus. Where Alternaria blight is a common problem, summer residents are advised to plant varieties resistant to it, for example, Filatovsky and Bryansky.
Dry rot
This disease is caused by fungi of the genus Fusarium. The first signs of powdery mildew appear when the plant is flowering. The spread of the disease begins with the upper leaves: they turn yellow and wither. An orange light coating appears on the stem. The peculiarity of Fusarium is that the plant is damaged very quickly. A few days are enough for the potato to die. In order to save the harvest, it is necessary to treat the plants with drugs such as Trichofit, Previkur or Fundazol.
Whatever the reason for the appearance of spots on potato tops, only quick, prompt actions will help to cope with it. In addition, preventive actions will help prevent such troubles: selection of disease-resistant varieties, pre-treatment of the soil, etc.
