Potato Blackleg: Control Measures (Photo)

Many gardeners are familiar with potato blackleg, but not everyone knows how to combat it. The disease itself is dangerous to the harvest. If the crop is left untreated and no measures are taken to save the tubers, half the harvest can be lost.

The disease is caused by three species of a single bacterium. Each type of bacteria has its own characteristics and ability to withstand various weather conditions. Any crop variety can be susceptible to the disease, but some have better immunity to blackleg. Nevertheless, all gardeners who value their work and harvest should know how to combat it.

Description of symptoms of black leg on potatoes

Pathogenic bacteria may not produce obvious symptoms for a long time, but the plant will still suffer from blackleg. This common disease occurs on tomatoes and eggplants. It is also common on cabbage, radishes, and peppers.

It's no wonder that many potato growers' guides recommend carefully inspecting the planted crop in order to detect the first warning signs in time.

Potato tubers are more susceptible, but the above-ground part also exhibits symptoms:

1. Brown spots appear on the stems.
2. The leaves curl up, start to turn yellow and dry out.
3. The shoots often become dark, sometimes black, and soft, with hints of spreading slime. The slime that appears on the shoots has a green tint.

In the initial stages of infection, pathogens multiply and attack plants, starting from the stem. From the stem, they confidently move to the roots, where they quickly attack the tubers. Infected tubers will have brown spots that become larger and darker over time. Depending on the severity of the infection and the activity of the microorganisms, the tubers may rot and turn black, lasting anywhere from several days to weeks.

Causes of infection

When potato stems turn black, gardeners suspect disease. But how many people have ever wondered how the disease develops or what causes it? Rain and dampness are ideal conditions for the spread of pathogens.

The cicada, a pest, can transmit the disease and viruses. The Colorado potato beetle can become another insect that carries the blackleg pathogen, along with wireworms and aphids. Potato blackleg quickly destroys tubers; photos of the pathogen's effects can be found online. Gardeners transporting fruit over long distances may not adhere to proper storage conditions, which, combined with insufficient fertilization during potato cultivation, can lead to blackleg.

Biology of potato blackleg

Potatoes are rapidly affected by blackleg, which causes the stem to blacken and rot. This is due to pectolytic enzymes, which cause soft rot and slime formation. The bacteria secrete an enzyme capable of causing maceration. Damaged plant tissue allows the disease to spread, and it is also spread by insects, which often attack crops. The bacteria that cause blackleg spread most easily in heavy, moist soil. The bacteria also thrive in sandy loam soil.

How to combat blackleg on potatoes

When potato roots turn black, gardeners panic. But the disease can be controlled, or better yet, prevented, with preventative measures. Using healthy planting material can significantly minimize the risk of potato infection with this dreaded disease.

The quality of planting material is the key to the quality of the harvest:

1. The crop should be planted only in areas free of pathogenic microorganisms.
2. If the soil has been infected with blackleg bacteria, then potatoes cannot be planted in it for at least three years, or even four.
3. The gardener should turn to crop rotation.

Signs of infection may appear some time after the first shoots emerge. The plant is dug up, replanting the bushes deep into the soil, using bleach as a top dressing. Many gardeners recommend burning infected bushes immediately to reduce the chances of spreading the infection.

Before harvesting, potato stalks should be mown and removed from the garden. Mowing should be done seven days before harvesting. Any organic matter left over from the potatoes should be burned away from the plot. To prevent soil, which may contain the microorganism that causes blackleg, from sticking to the dug-up tubers, harvesting should be done in dry weather.

Drying the tubers before storing is essential. Many gardeners prefer to green up their potatoes before storing them for the winter.

An effective method is to use a chemical treatment. The tubers can be treated with a product called TMTD or VSK. Dissolve 4 liters of the product in 70 liters of clean water. This is enough to treat a ton of potatoes.

Reviews

Maxim:

"I've been growing potatoes for many years. I rarely encounter blackleg. I try to monitor the development of the seedlings and prevent the spread of the infection. I can't wait to let the microorganisms spread to neighboring plants. I know from personal experience that this can happen quickly. I don't have time to go to my dacha to check on the potatoes often, so I try to regularly treat the tubers with biological agents before planting."

Michael:

"I used TMTD last time to treat tubers before planting. The results were good. There were no problems with the harvest; we enjoyed good tubers. We didn't even have to remove any infected plants from the garden; there simply weren't any."

Anastasia:

"A neighbor complained about blackleg. I haven't had it in three years. I've gotten into the habit of carefully sorting through the tubers before planting. And when digging, it's best to discard any suspicious fruits immediately. If you keep your potatoes green, fertilize them frequently, and treat them regularly, there's no chance of the blackleg pathogen spreading."

Igor:

"Blackleg is a serious problem. I never thought the disease could progress so quickly. One year, I lost about half my crop. Since then, I haven't planted tubers without pre-treatment."

Alexandra:

"I can confidently recommend Fitosporin-M to everyone, although there are many worthy alternatives on the market. But I always buy this product to treat blackleg before planting. It's extremely effective, and there's no cause for concern with proper crop care."

Tamara:

"Blackleg is an insidious disease that can creep up quickly and unnoticed, but vigilant gardeners always recognize the first signs of the disease and destroy infected plants. If you fertilize potatoes promptly and care for them properly, this problem and other troubles will be avoided. Potatoes require attention. For reliability, you can use biological treatments, but I rarely do this. I prefer to choose varieties that are naturally immune to blackleg.