In addition to all the familiar pests of potato culture - the hated Colorado potato beetle , there are many more diseases that lead to a decrease in yields. Some diseases lead to twisting of the leaves. Let's talk about this unpleasant phenomenon and methods of fighting against it in the article.
The leaves of the potato twist - the causes
The first group of causes is viral diseases. These include:
- Wrinkled mosaic. The defeat is accompanied by a lag in growth, a small number of stems, wrinkles and twisting of the edges of the leaves. The latter is a consequence of slow growth of veins.
- Stripe mosaic. The disease manifests itself during the budding of potatoes. At first, dark brown spots are visible - necrosis of the leaves from the lower side, with more severe lesions the leaves twist die, hang on the stems. Basically, the lower leaves are affected, the tip remains green. These symptoms intensify during a period of intense heat.
How to deal if the leaves of the potato twist due to virus infection: protection of potatoes from viral diseases is the timely removal of diseased plants along with their tubers, weed control, timely harvesting. As the seed, only the best tubers purchased in specialized stores should be selected.
The second group of reasons for twisting the leaves of potatoes are fungal diseases:
- Phytophthorosis - affects not only the leaves, but also the stems and potato tubers. First, gray and brown spots appear on the leaves, if the plant is not treated, the tubers on the cut will become brown and dense. Methods of struggle are the prevention, the introduction of the necessary trace elements in the soil, during the growing season you need to process the bushes with medicated preparations.
- Parsh - leads to the twisting of the leaves, the roots of the potatoes are browning and gradually die. Weak plants are more susceptible to this disease. After sprouting tubers, the disease does not affect the seedlings. So it's best to plant already sprouted potatoes and make sure that there are no soil crusts on the ridges. Before planting, the tubers are treated with a 1.5% solution of boric acid.
The following reasons why the potatoes are curled leaves are associated with bacterial diseases. The main one is a black leg. It develops during the storage of tubers, as well as during the growing season of the plant. First, the apical leaves curl in the potato, then the base of the stem turns black and rot. Only preventive measures will help here: preliminary germination of tubers, their soaking in a solution of microelements - boron, copper sulfate, manganese and zinc.
Sometimes the reason that the potatoes turn yellow and the leaves twist are drought and intense heat, what to do in this case: watering and humming bushes, you can wrap up the beds to keep moisture in the soil longer.