Content
Stolbur or phytoplasmosis of tomatoes is a dangerous disease that can cause the death of up to 80% of the crop. It is focal in nature and most often found in the southern regions of the country, since low air humidity and high temperatures are optimal conditions for the reproduction of its vectors. Treatment of tomato stolbur is difficult, since when obvious signs of damage appear, the infection has time to spread to most of the plantings. However, with timely measures taken, it is possible to save most of the crop, as well as prevent the development of the disease in the next season.
Infection occurs in the early stages of tomato development.
What kind of disease is this
Stolbur or phytoplasmosis (Tomato stolbur phytoplasma, Aster yellows phytoplasma) is an infectious disease caused by phytoplasma, which is an intermediate life form between bacteria and viruses. Crops grown in open ground are more susceptible to the disease.
Stolbur affects all types of nightshade crops, as well as some herbs and shrubs, including sow thistle, plantain, St. John's wort, bindweed, spurge, chicory, nettle, chamomile, and elderberry. The incubation period of the disease is 30 days.
Causes
The infection is transmitted by sucking pests, namely: leafhoppers, psyllids, and some types of moths. Early damage to tomato seedlings by phytoplasmosis is explained by the beginning of active summer in the first days of June of insects, and mass distribution is observed already at the end of July. The likelihood of infection persists for 2.5 months, during which the leafhoppers actively reproduce and transfer the infection from diseased bushes to healthy ones.
Signs of the appearance of stolbur on tomatoes
The first sign of damage to tomato bushes by stolbur is deformation of their vegetative parts. Shoots and leaves initially acquire an anthocyanin hue. The color changes first at the top of the plant, and only later the changes become noticeable below. Terry appears on the plates and chlorosis develops.
Often the leaves curl upward, taking the shape of a boat.
Subsequently, in the absence of treatment, the roots of the affected plant become covered with microcracks. The shoots begin to accumulate starch, as a result they become lignified and become brittle. The color of the roots noticeably darkens and in most cases becomes brown.
With the spread of the disease and untimely treatment, the petals increase in size and grow together, so eventually the inflorescences take on the shape of a bell.
The corolla and pistil stop developing, and the stamens shorten
The affected bushes do not bear fruit, and if this happens, the tomatoes become unsuitable for fresh consumption and processing. At this stage of development of the disease, the bushes are no longer treatable.
On infected plants, tomatoes grow small and tasteless. You can cut such tomatoes only with force. Inside them, seeds may be completely absent or contained in minimal quantities.
The pulp of tomatoes becomes lignified and consists of vascular-fibrous bundles; when pressed on them, a light liquid is released
The carbohydrates in affected tomatoes are converted to a type of cellulose. This can be determined by the whitish veins on the pulp.
How dangerous is the disease?
The danger of stolbur is that often the first signs of damage go unnoticed. After all, the anthocyanin tint that leaves and shoots acquire most often indicates a lack of phosphorus in the soil. And this leads to incorrect treatment.
And even with the massive spread of the stolbur tomato disease, not all gardeners know what to do correctly and what means need to be used to preserve the crop. And this leads to significant losses not only in the current season, but also in the next one. After all, the source of infection, in the absence of proper treatment, can persist for a long time in the roots of perennial plants, since they act as reservoirs of pathogens.
Infected seedlings are stunted in growth and development
How and with what to treat tomato stolbur
Only comprehensive control measures can stop the spread of stolbur on tomatoes in open ground, as well as prevent the occurrence of infection in subsequent seasons. For treatment, you can use agrotechnical methods, folk remedies and special preparations. But you should understand that it will be possible to get rid of the infection only with their combined use and long-term treatment.
Agrotechnical methods
This method of control involves timely weeding of tomato plantings in order to destroy possible reservoirs of infection. Also, to prevent the spread of stolbur, it is recommended to choose varieties that have high natural immunity. To treat and protect tomatoes, experienced gardeners recommend planting curtain plants around the tomato bed and in the inter-row spaces. Their function is to protect tomato plantings from pests that are carriers of infection.
Legumes, sunflowers, rye and corn can be used as cover crops.
Folk remedies
Folk remedies help increase the resistance of tomatoes to adverse external factors and protect the bushes from damage by leafhoppers and other pests. They can also be used to treat diseases during the fruiting period of tomatoes, when the use of chemicals is unacceptable. However, it is worth understanding that this method provides a short-term protective effect, so it is recommended to treat plants regularly every five days, as well as after rain.
Effective folk remedies for protecting tomatoes from stolbur:
- Grate 100 g of tar soap and pour 3 liters of boiling water over it. Add an additional 3 tbsp to the resulting mixture. l. sugar and stir until smooth. It is necessary to use the product for treating tomatoes throughout the entire growing season.
- Grind 200 g of garlic to a paste consistency. Pour the mixture into 3 liters of hot water and add 100 g of tobacco. Mix the product thoroughly and leave for a day. Before processing the tomatoes, strain the mixture and add 1 tsp. dishwashing detergent.
- Heat 5 liters of whey to +40 °C. Then add 30 drops of iodine and 3 tbsp. l. Sahara. Mix the product until it is homogeneous and can be used immediately to treat tomatoes.
Preparations for tomato stolbur
To protect tomatoes from stolbur, it is recommended to use special preparations. To do this, you need to use insecticides when planting seedlings in a permanent place and throughout the entire period of active summer of leafhoppers. To treat tomatoes in this case, you need to use Fufanon, Aktar, Decis, Actellik, Fitoverm.
Treatment frequency: every two weeks
For the prevention and treatment of stolbur on tomatoes, it is recommended to use biological agents such as Fitoplasmin and Fitolavin. The first preparation should be used for watering seedlings at the root 1.5 months after planting the seedlings in a permanent place. The protective effect lasts for 20 days. Then it is recommended to spray the bushes with these drugs, alternating them to avoid addiction. Treatment can be carried out until mid-August, strictly adhering to the instructions for the preparations.
Treatment of stolbur is possible only with the use of antibiotics
Measures to combat tomato stubble in a greenhouse
It is much easier to fight this disease in closed ground conditions. This is due to the fact that leafhoppers do not tolerate high air humidity. However, to protect tomatoes in a greenhouse, it is necessary to use the same insecticides as for treatment in open ground, only in a lower concentration. Bushes should be treated every three weeks, alternating products.
It is not recommended to use Phytoplasmin in greenhouses, since its phytotoxicity manifests itself at elevated temperatures and insufficient light.
Preventive actions
Since tomato stubble is caused by phytoplasmas that are not very susceptible to most known fungicides, prevention is extremely important. It cannot completely eliminate the possibility of damage, but it allows you to reduce the risks to a minimum and avoid further treatment.
Basic preventive measures:
- regularly spray tomatoes with repellents;
- when plowing a plot in autumn, add copper sulfate and wood ash to the soil;
- regularly feed the bushes to maintain a high level of immunity;
- remove weeds in a timely manner throughout the entire growing season of the crop;
- Grow tomatoes in greenhouses if possible.
Resistant varieties
You can get a good harvest of tomatoes by choosing varieties that are resistant to leafhopper damage. Therefore, if the prevalence of the disease is high in the region, they should be given preference.
Resistant varieties include the following types:
- Volgogradsky 5/95;
Volgogradsky 5/95 – mid-season semi-determinate variety
- Sovereign F1;
Sovereign F1 is resistant to transportation
- Legionnaire F1.
Legionnaire F1 – early ripening salad variety
Conclusion
Treatment of tomato stolbur is possible only at the initial stage of crop damage and with timely detection of signs of the disease. Therefore, every gardener must follow preventive measures to eliminate the possibility of damage. However, it is worth understanding that they will only be effective if they are used regularly.
