What is potato scab?
And it’s called a disease – an ordinary one, that is, a completely ordinary phenomenon, that’s how widespread it is. So we got used to the scab, which we take for a normal phenomenon. The taste of potatoes affected by scab worsens, the starch content decreases, there is more waste during cleaning. Useful biologically active substances do not remain at all. In addition, tubers do not store well, as scab ulcers cause dry and wet rot during storage.
This potato disease cannot be eliminated as long as we use diseased tubers for planting, as long as we plant potatoes in the same place, as long as we apply manure to the soil under potatoes. Most of all, scab develops in hot, dry summers. There are varieties of potatoes that are resistant to the disease.
Potato scab control and prevention
The main emphasis in the fight should be on the prevention of the disease. We must make it a rule to return potatoes to their original place only after 2-3 years. The best predecessors are beets, carrots, cabbage, corn, cereals, legumes. After harvesting vegetables, sow siderats on the soil – plants that improve and heal the soil, which are left for the winter and in the spring they dig up their remains. Grain rye, wheat, oats are sown as green manure (but it attracts wireworms), legumes – lupins, beans, clover, cruciferous – mustard, rapeseed.
Green manure, when decomposed in the soil, enriches it with organic matter and mineral salts and promotes the development of saprophytic fungi and bacteria that kill scab pathogens.
The introduction, as a control measure, into the soil directly under the potato of microelements – copper, manganese, boron significantly reduces the scab disease.
It is necessary to water the potatoes from the moment the tubers are set and until they reach a diameter of 2-3 cm, that is, from the appearance of tops to flowering.
It is also very useful to mow the tops 10 days before harvesting the potatoes, which contributes to good ripening, the formation of a thick skin, which will allow the potatoes to be well stored and not become infected during storage.
Scab resistant potato varieties
With a strong infestation of the site with pathogens of common potato scab, it is necessary to cultivate varieties resistant to this disease – Aspiya, Bezhitsky, Bryansk novelty, Varmas, Vestnik, Vilnya, Vyatka, Zhukovsky early, Lyubimets, Posvit, Prasna, Reserve, Rodnik, Skoroplodny – these are domestic varieties. Of the foreign ones, resistant to scab are Alpha, Element, Krostotr, Lady Rosetta, Mentor, Nicolas, Ostara, Patrones, Prevalent, Prokura, Saturn. But even when growing these varieties of potatoes, the above measures should not be neglected.