Potato Diseases

2024 Author: Jasmine Walkman | [email protected]. Last modified: 2023-12-16 08:29

Today potatoes are one of the main products we put on our table, but they did not arrive in Europe until the end of the 15th century together with the first ships returning from America.

They originate from the Andean region and in these lands there are more than 200 wild varieties of the plant. Edible potatoes are also a variety of varieties, differing in shape and color.

Unfortunately, like any plant, and the potato is sick.

Potato diseases are divided into 3 main types - fungal, bacterial and viral. Fungi include manna, black leaf spots, scabies, scab and dry rot.

Bacterial are blackleg and bacterial soft rot, and viral - potato leaf curl virus and varieties of Y potato virus.

Here are the basic things you need to know about these potato diseases.

Mana

This disease affects the stems, leaves and tubers and can destroy the crop in about two weeks if no action is taken. It spreads at a relative humidity of 100% and at a temperature of 21 degrees Celsius.

To avoid manna on potatoes, use varieties with high disease resistance. Choose healthy seeds and destroy potatoes of unknown origin.

Avoid the accumulation of piles of waste near the plantations and inquire about the types of fungicides and how to use them during the different stages of the disease.

Black leaf spots

These black spots on the leaves, also called early mana or Alternaria solani, are concentrically growing rings of irregular shape. Their color is black or dark brown, and their size varies from a few millimeters to two centimeters. Affected leaves usually fall off before the targets are covered with spots.

Fungal infection in potatoes survives in the ground in the form of spores on leaf litter and is carried by wind and water.

It can infect potato crops at any stage of development. Favorable temperature for early mana is in the range between 10 and 35 degrees Celsius. To control the disease, use uninfected seeds and appropriate fungicides.

Scabies

This disease worsens the quality of potatoes. It affects the skin of potatoes and occurs at lower temperatures and a wide range of soils.

This potato disease is expressed in the formation of rough star-shaped lesions on the tubers and if they are harvested in still moist soil, a white-gray layer of spores is formed on the scars, which disappears after the surface dries.

Some varieties of potatoes are more susceptible to this disease than others. It does not affect the quantity, but only the quality of the harvest. To control the disease, use resistant varieties and avoid sandy soils with high pH. Use suitable fertilizers and fertilizers and keep the furrows moist during the germination period.

Scabbing

This disease is black flakes on the surface of potatoes. It significantly reduces the yield, worsens the shape of the tuber and is also the cause of green potatoes.

These hard black scales are usually between 1 and 5 mm in diameter and 1 to 10 mm in length, but may be completely covered with a black coating.

This type of disease survives in storage and in the soil. The temperature of 10 degrees Celsius is favorable for its development, because then the sprouts develop more slowly and the fungus has time to infect potatoes.

To avoid potato disease, do not plant potatoes at low soil temperatures and use uninfected seeds.

For planting, choose rotten seeds and plant shallow so that there is no time for the infection to spread. Consult an agronomist to select appropriate fungicides.

Dry rot

The fungal infection Fusarium sulphureum and Fusarium solani var coeruleum can develop both in the tubers themselves and in the soil.

This disease usually begins after the harvest, and significantly reduces yields. Collecting injuries are potential foci of infection that can be infected.

As a result of dry rot, tubers can become infected with secondary invaders such as fungi. The disease begins with small brown spots on the bark that develop into cavities inside the tuber. The bark becomes wrinkled and deformed. Temperatures between 15 and 20 degrees Celsius and relative humidity are most favorable for rot.

To avoid potato disease, use uninfected seeds, protect the tubers from injury during harvest and provide conditions for wound healing by ensuring an appropriate temperature. When storing potatoes, control with the necessary chemicals.

Black foot

The symptoms of this disease and stem rot are difficult to distinguish. Black foot disease occurs in areas with moderately cool climates at temperatures between 18 and 20 degrees Celsius.

Rot begins in the tuber and develops on the stem, which turns black. This disease can lead to mild rot at any time due to the interaction with bacteria. The symptoms of different varieties may be different.

Stem rot most often affects potatoes grown in warm climates. It is characterized by rot of the stem and tuber. It is watery and odorless. In the hottest period of the day the tops of the plants wither and the process is reversible, but under adverse conditions it can lead to necrosis.

For successful prevention against blackleg and stem rot do not use contaminated batches and strictly follow all sanitary measures during cultivation. Clean the machines after use and remove infected tubers. Keep them away from crops.

Bacterial soft rot

This type of rot is caused by a bacterium called Erwinia carotovora and lives in any type of soil. Favorable conditions for the bacterium are the wet soil during cultivation and storage in moist rooms.

Symptoms of initial infection are small brownish-yellowish oval areas. If the potatoes are removed at the beginning of the disease, the disease can be stopped, but it is important to store the potatoes in a dry place. As a result of the development of the disease, the tubers become covered with a slippery liquid and have an unpleasant odor.

Chemical means to deal with this disease on potatoes are not known, but as a preventive measure you can avoid flooding the soil, remove infected tubers and store them in dry and cool places.

Potato leaf curling virus

The PLRV virus is spread all over the world. The virus attacks crops at an early age and can halve yields.

The symptoms of the disease begin with the leaves turning inwards and turning yellow. Symptoms on the tubers almost do not appear, but with the development of the disease the whole plant becomes hard and the leaves wither.

The virus is spread only by aphids.

To avoid the disease, use only seeds of proven origin. If the plants get sick, remove the infected ones in the initial phase and destroy them. In case of aphids, use an insecticide immediately.

Varieties of Y potato virus

It is one of the most dangerous viruses for potatoesbecause it is easily transmitted and causes large losses in yield.

Its combination with other viruses can reduce yields by up to 70%. They are transmitted by different types of aphids, the main vector being the peach-potato aphid.

To avoid the virus, use seeds of proven origin only, grow potatoes in a virus-free environment and remove infected plants as early as possible. Spray the crops weekly with mineral oils and harvest on time.