Agronomists know many
diseases of potato. Late blight is perhaps one of the most dangerous of them. Its harmfulness increases significantly in areas of temperate or humid climate.
This disease is common in all those countries where potatoes are grown en masse. On average, crop losses from it can reach up to seventy percent.
Potato late blight is a fungal disease caused by a pathogenic organism. It affects tubers, stems, flowers, root crops.
The first signs of the disease are noticeable on the foliage and stems of the upper tier. Potato late blight is highly harmful because it affects the young and physiologically most active parts of the plant, reducing their productivity.
With a decrease in the assimilating surface on the leaves of the root, the process of formation and accumulation of many nutrients is disrupted, especially in the phase of tuber formation.
As a result, brown individual spots with a characteristic leaden hue appear on the leaves. They significantly increase, very quickly covering the entire bush, and then spreading to neighboring plants.
Under favorable conditions, late blight of potatoes spreads so intensively that in just seven or ten days it can cover the entire area.
On the affected bushes in the early morning or in wet weather, a whitish coating appears on the lower surface of the leaves.
These are the spores of the fungus that has engulfed the plant. In dry weather, the affected upper part dries out, crumbling. After the rain, it quickly rots, spreading a moldy smell around the faint.
Potato stem blight is characterized by the formation on the cuttings of strips of dead brown tissue. Sometimes they cover the entire upper part of the plant.
On tubers, this disease is manifested by hard depressed, clearly defined spots that are especially visible in the section of the fetus. Other bacteria with fungi penetrate into the affected tissues, which even more intensify rotting of the root crop.
Potato late blight affects only fruits that are in the early stages of ripening. At first, a barely noticeable white round spot appears, which gradually diffuses into a brown subcutaneous formation. Growing in size, late blight gradually capture the entire potato, which softens and begins to rot.
This fungal disease destroys not only potato crops, but also nearby tomato bushes. An interesting fact is that the crops of eggplant and zucchini are absolutely not affected, even with very close proximity to infected plants.
Today, the fight against late blight of potatoes is mainly in the use of seeds of resistant varieties. In addition, careful selection in the preparation of material for planting is of great importance for limiting the development of this fungal disease.
In some countries, seed potatoes are treated with fungicides during storage. This is done to exclude the development of rot, including late blight.
Since the primary sources of infection are almost always diseased tubers, experts advise destroying the dumps of potatoes left after the bulk harvest.