Potato diseases

Late blight

Late blight is one of the most harmful and widespread fungal diseases of potato. It causes the greatest damage in zones with abundant atmospheric precipitation in the second half of summer. The regions with the greatest harmfulness of this disease include the northwestern and mountain areas, the Far East, as well as the Baltic countries and Belarus (VIZR). In the central regions of the Non-Chernozem zone, it is observed on average once every two years, not always severely, but losses from it amount to 10–12%, in some years up to 30%.

For late blight, application of copper sulfate to the soil at 4 kg/ha is effective.

For spraying plants against late blight, 80% zineb — 3 kg/ha, 80% kuprozan — 2.4 kg/ha, Ridomil 0.8–1 kg/ha, Bactofit, Alufit, Ditan, Pencozeb, Mancozeb, Profit, Acrobat MZ, Yunomil MZ, Metaxyl, Ridomil Gold, Sectin, Fenomen, Kuproskat, Bordeaux mixture, Kartotsid, Kuprokol, copper oxychloride, Abiga-Pik, Kurzat, Ordan, Tsikhom, Tanos, Shirlan, Folpan, Bravo, Zineb are used.

For treating tubers before planting, Fitosporin-M, Bactofit, and TMTD are used.

For fumigation after placing into storage — VIST (bulk fumigation cartridges), Maxim (for seed potatoes).

Potato wart

Potato wart was first detected in the USSR in 1936 in Ukraine, later spreading to the western, southwestern, northwestern, and central regions of the country. The disease causes large yield losses, sometimes complete destruction of the crop.

Wart affects potato during the growing season, but is detected only at harvest, since the disease influences potato development and affects tubers and stolons, while the roots remain healthy.

Rhizoctonia

Rhizoctonia is widespread in all potato-growing areas. The disease causes the greatest damage in regions with a cold, long spring. Soil with a high humus content and high moisture are favorable for the development of the rhizoctonia fungus.

For disinfecting seed material against rhizoctonia, TMTD, Fitosporin-M, Bactofit, Kolfugo Super, Maxim, and Fenoram Super are used.

For treatment during the growing season, Bactofit and Kuproskat are used.

Common scab

Common scab is a widespread disease of potato tubers of fungal nature; it is especially severe on soils light in granulometric composition. Losses from this disease are difficult to estimate, since yield does not decrease, but the market value of tubers decreases, and the seed quality of tubers also deteriorates.

To control common scab, it is recommended to use acidic forms of fertilizers, for example, ammonium sulfate and superphosphate, which are applied in rows at planting at 100–150 kg/ha. In contrast, fresh manure and lime at increased application rates increase tuber infection by scab.

For disinfecting seed material against scab, TMTD is used.

For disinfecting seed potato tubers before placing them into storage against silver scurf, the preparation Maxim is used.

Ring rot

Ring rot leads to premature wilting and death of haulms and rotting of tubers in the field and during storage. Tuber losses from this disease by harvest can reach 11–44.5%. Ring rot is widespread in the northern and middle belts of the European part of Russia and Siberia.

Black leg

Black leg is widespread in all countries where potato is cultivated. In Russia, this disease occurs in the middle and northern zones of the European part, in Siberia, and in the Far East. As a rule, the proportion of diseased plants is 1–10%, but in rainy years this proportion can increase substantially.

Under conditions of insufficient soil moisture and elevated temperatures, disease development stops, and harvested tubers may have no external signs of infection. However, tubers with a latent form of infection begin to rot during storage and infect other healthy tubers, which leads to large losses.

Wet, or bacterial, rot

Wet, or bacterial, rot is widespread in all countries cultivating potato. Losses from the disease can reach 10–15%.

Bacteria enter tubers through places damaged by insects, through damage by late blight, scab, when tubers are in waterlogged soil, etc. Tubers with intact skin are practically not affected by wet rot.

If the storage regime is disrupted, for example by increased humidity or temperature, the disease develops very quickly. Rotten tubers completely decompose within 1–2 weeks. Under normal potato storage conditions (low temperature and good ventilation), bacterial rot develops slowly and rarely spreads to healthy tubers.

For pre-planting treatment of tubers against rots, Fitosporin-M (dry and wet rot), Kolfugo Super (dry rot), and TMTD (bacterial rot) are used.

For fumigation of tubers after placing into storage — VIST (cartridges) and Maxim (for seed potatoes against wet rot).

Macrosporiosis

For treating plants during the growing season against macrosporiosis, Ditan M-45, Pencozeb, Mancozeb, Profit, Acrobat MZ, Kuproskat, Bordeaux mixture, and Abiga-Pik are used.

Alternaria blight

For treating plants during the growing season against Alternaria blight, Acrobat MZ, Yunomil MZ, Metaxyl, Ridomil Gold, Sectin Fenomen, Kuprokol, copper oxychloride, Ordan, Tsikhom, Tanos, Shirlan, and Folpan are used.

For treating seed potato tubers before placing into storage — Maxim.

Viral diseases

Viral diseases are widespread in all countries of potato cultivation. They become the main factor preventing the spread of crop plantings in areas with warm and hot climates.

Worldwide losses of tuber yield from viral diseases are difficult to estimate, since in most cases there is no reference for comparison (healthy plantings), but they are assumed to be large.

It has been established that diseases such as stolbur and witches' broom, previously classified as viral, are caused by microorganisms of the mycoplasma group. Also, viroid diseases have been separated from the group of viral diseases, that is, diseases whose pathogens are a stable <abbr title="Ribonucleic acid">RNA</abbr> without a protein coat. Viroids include a disease widespread in Russia — gothic, or spindle tuber.

Symptoms of viral diseases: curling and wrinkling of leaves, mottling (mosaic), and small tubers.

References

1. Vavilov P. P., Gritsenko V. V., Kuznetsov V. S., et al. (1986). Crop Production. Edited by Vavilov P. P. 5th ed., revised and enlarged. Moscow: Agropromizdat.
2. Kolomeichenko V. V. (2007). Crop Production/Textbook. Moscow: Agrobiznescenter.
3. Niklyaev V. S. (2000). Fundamentals of Agricultural Production Technology. Agriculture and Crop Production. Moscow: Bylina.
4. Rubatzky, Vincent E., Yamaguchi, Mas. (1997). World vegetables: principles, production, and nutritive values. 2nd ed.