Content
Beet cercospora is a dangerous fungal pathology that affects all varieties of the crop. The first signs are noticeable on the leaves - they become covered with spots, then curl and die. The disease leads to a decrease in yield, so if symptoms are detected, several treatments with drugs must be carried out. The use of folk remedies is ineffective - only chemical and biological fungicides give results.
Causes of defeat
Beet cercospora blight is a fungal infectious disease caused by the pathogen Cercospora beticola Sacc. It is found everywhere, affecting beets of different types and varieties. The name is associated with the source of infection - Cercospora. She overwinters in dead tops. In spring it becomes active and infects plants through the stomata. Most often, pest penetration occurs in the morning.
The latent period lasts 7-14 days in summer and 30-40 days in autumn. At this time, no symptoms are noticeable. Over time, the leaves become stained, the tops lie down, and the cercospores overwinter in them again and infect new plants next spring.
The main cause of infection is the alternation of hot, dry and relatively warm, humid weather. This phenomenon is often observed in different regions of Russia. Spores successfully spread in the soil, so the risk of damage cannot be completely eliminated.
Description of beet cercospora with photo
The causative agent of beet cercospora mainly affects the leaves, but can also appear on the stems and petioles of plants. The first symptoms are noticeable on well-developed tops already at the end of June. The main signs of the disease are easy to determine visually:
- Small round spots of a grayish or brown tint with a bright red or brown border appear on the leaves.
- A grayish velvety coating forms over the affected areas; it appears especially quickly in humid weather.
- At advanced stages, the leaf blades curl downward along the center. They completely lose their elasticity, dry out and die.
- The tops lie on the ground. The row spacing opens, while the young foliage itself in the middle of the rosette remains healthy.
The damage to the tops by cercospora can be easily determined by visual inspection
Control of cercospora blight in sugar beet
Beet cercospora can be treated in different ways. The main measure is treatment with chemical and biological fungicides. Drugs belonging to the classes of triazoles, strobilurins, and benziamidazoles are especially helpful.
Effective fungicides against cercospora blight of sugar beet
The first treatment is carried out when stains appear.The second, third and subsequent (if necessary) are repeated at intervals of 7-10 or 14 days, depending on the characteristics of the drug.
For prevention at the beginning of the season, Fitosporin is used. It belongs to the biological fungicides. The active ingredients are strains of bacteria. The product is completely safe for humans and does not pose a threat to bees.
You can also use the fungicide “Doctor Krop” for prevention. This is a chemical fungicide that effectively destroys the causative agent of cercospora when growing beets in different climatic conditions.
At the first appearance of symptoms of the disease, use “Pseudobacterin-2”, “Gamair” (biofungicides) or “Zoltan” (chemical). All products completely destroy pests, while being used sparingly. They are low-hazard for humans and bees (class 3).
Subsequent treatments are carried out as necessary. For this, other fungicides described below are used.
Progressive beet cercospora disease affects most of the tops
For subsequent treatments with an interval of 1-2 weeks, the following drugs are used:
- "Benazol, SP" is a systemic fungicide against many diseases. Cercospora is used for treatment and prevention; it begins to act within three hours after treatment. Compatible with most other drugs, can be used in tank mixtures. The dosage of the drug for treating beets is 600-800 g/ha. Treatment is carried out by spraying until the pest is completely destroyed.
- "Vintage, ME" is a combination drug characterized by a wide spectrum of action and rapid penetration to the affected area. The product is released in liquid form. The consumption rate is 600-800 ml of pure product per hectare. Used for both ground and airborne processing.
- “ZIM 500, KS” is a systemic chemical fungicide that destroys the causative agent of beet cercospora. They are used not only for treatment, but also for prevention. Compatible with most drugs, used in tank mixtures. Available in liquid form. The consumption rate of pure preparation is 600-800 ml per 1 hectare. Also used for seed treatment.
- “Mysteria, ME” is a remedy against beet cercospora based on three active ingredients. Reduces the sensitivity of plants to hot, dry weather and temperature changes. The protective effect lasts 2-3 weeks, so if necessary, the last treatment of even late varieties can be carried out in early August. The drug is produced in liquid form, the consumption rate is 1.0-1.25 liters per hectare.
- “Title 390, KKR” is a systemic chemical fungicide. It is used for ground and aviation processing. The protective effect lasts for 3-4 weeks, and it begins within a few hours. The consumption rate is 260 ml per 1 ha (in terms of pure solution).
- “Bordeaux mixture” is a universal fungicide based on copper sulfate and calcium hydroxide. Used as a solution with a concentration of 1%. It is not recommended for repeated treatments, since copper accumulates in the soil and takes a long time to be removed.
- "Abiga-Pik" is a preparation based on copper oxychloride. Chemical fungicide for universal use. It is used to combat various diseases, including cercospora. It is often used as an additional remedy when pests have already developed resistance to other drugs.
The pest has been developing for a long time without signs of damage, so time has already been lost.Only drugs can help cope with it.
Agrotechnical techniques
Treatment with fungicides is the main means of combating beet cercospora. But along with them, other techniques should be used:
- Plant varieties and hybrids resistant to cercospora (for example, Incomparable A-463, Kuban polyhybrid 9, Ganusovskaya single-seeded 55, Pervomaisky polyhybrid 10).
- Carefully destroy all leaves and petioles after harvesting. They need to be taken as far as possible and burned. You should not use such material for mulch.
- Maintain crop rotation - change the planting site every 4-5 years.
Disease prevention
Cercospora blight is a dangerous and at the same time common disease of beets. Dealing with its consequences is not always easy. Therefore, you should be aware of certain preventive measures:
- Do not plant beets in low-lying areas where moisture accumulates after heavy rains.
- Do not plant too thickly, do not plant other crops. Maintain an interval between rows of 50 cm.
- Apply fertilizers, especially phosphorus and potash. During the season, two feedings are given, observing the norm per 1 square meter: 30-40 g of superphosphate, 20-30 g of potassium sulfate.
- Plant beets in a field where onions, potatoes, cucumbers, green manure, and carrots previously grew. It is worth considering that the worst predecessors are tomatoes, cabbage and other beet varieties.
- Finally, plantings should be treated promptly with fungicides at the beginning of the season. Products such as Fitosporin and Doctor Krop are well suited for this.
Conclusion
Beet cercospora affects all plantings; the disease is dangerous, and it is not so easy to cope with. As a rule, the problem is solved by preventive treatments at the beginning of the season.You should also use varieties that are resistant to this infection, but there are not many of them yet. If signs of disease appear, several treatments should be carried out at intervals of 1-2 weeks.
