Why spots appear on leaves and fruits of pepper
Vegetable spotting is one of the most common causes of crop death. This pathology is observed annually on the fruits of various cultures, including bell pepper. This article will discuss the main causes of dark spots on peppers, and also describe what needs to be done to eliminate them.
Why do spots appear on peppers
The appearance on the pepper of brown, white spots and other inclusions always indicates all kinds of violations of the agricultural technology of growing crops. However, the cause of this pathology can be different - from improper irrigation conditions to damage to plantations with complex infections.
Problems with leaving - this is the first thing the vegetable grower should suspect if spots have appeared on his peppers. Bell pepper came to European culture from tropical regions, so creating optimal conditions for it is not easy.
Crop rotation failure
In the pursuit of an abundant harvest, farmers often neglect crop rotation on the site. As a result, the soil is saturated with toxins and all kinds of secretions, which have a detrimental effect on the stands; in particular, they become a source of various pests and infections. Therefore, the landing of culture at the same place for several years is unacceptable. In addition, often plantings of vegetables alternate with tomatoes, potatoes, eggplant and other representatives of solanaceous plants, which depletes the soil and creates an unfavorable infectious background on the site.
Learn more about what to plant after pepper next year.
To avoid this, a balanced crop rotation system needs to be created on the site: it is conditionally divided into several zones, which are planted alternately with various crops.
Pepper is grown on one site no more than 1 time in 3 years - this is the so-called three-year crop change system:
- after pepper, cucumbers, zucchini, onions, carrots, cabbage are planted. After that, in winter, the plot is sown with siderates, which then mow and plow in the soil;
- in the second year, legumes or cruciferous plants are grown on the site;
- in the third year, pepper planting is repeated.
Nutrient deficiency, nitrogen
Lack of nitrogen in plant nutrition leads to degeneration of chlorophylls, photosynthetic components of foliage. In this case, single or numerous small green spots can be observed on the leaves. Most often they can be found after transplanting seedlings, in the phase of active development of plants. Often, a deficit of nitrogen in the soil threatens plantings not only with external manifestations, but also with a general inhibition of growth, as well as a decrease in productivity. This leads to neglect of pre- and post-planting fertilizers of the soil by complex organic and mineral mixtures.
To avoid this, the site must be well fertilized with nitrogen compounds before planting. Most often, manure (5-6 kg / m²) or all kinds of mineral fertilizers are used for this. Ammonium nitrate and urea (50 g / m²) have proven best. Fertilize the soil approximately 7–10 days before the estimated planting date. Additionally, after 7-14 days, the soil can be poured with liquid solutions of concentrates (50 g per 10 l of water).
Non-compliance with the irrigation regime
Optimum water management is one of the main conditions for good care. Its absence leads to a variety of diseases, including putrefactive spotting. Usually it occurs with a sharp overmoistening of the beds, when an ideal environment for the development of pathogenic fungi is created. However, water scarcity can also cause spotting. In this case, with a lack of moisture on the green mass of pepper, dry spots are observed, which gradually lead to the withering of the entire leaf, as well as the fruits.
Did you know? Despite the prevailing opinion, the fruits of sweet pepper, from a botanical point of view, are not vegetables, but berries.
Such pathologies can be eliminated by a sharp change in the water regime of the site. To do this, when watering, you must adhere to the following recommendations:
- when moistening the soil, the soil should be soaked to a depth of not more than 0.6–0.7 m;
- only the soil is watered near the basal column; row-spacing moistening is irrational;
- the procedure is carried out as necessary, only after the appearance on the site of a small dry crust with a thickness of about 4 cm;
- sudden changes in substrate moisture are fatal, the optimal rate should be within 70%;
- watering is carried out in the early morning or late evening, and only under the root.
Infectious lesions on sweet pepper stands are not uncommon. In nature, there are many parasites of this culture, which under favorable conditions instantly infect pepper tissue and its fruits. It is completely impossible to solve this problem - microorganisms are able to adapt to new living conditions, including the effects of plant protection products. Therefore, in order to protect the beds from them, it is necessary to get rid of the main reason for their distribution - favorable conditions for pests.
By mosaic is meant an infectious disease caused by a group of specific viruses. The causative agent of the disease reduces the gas exchange between the green mass and the environment - because of this, the plants overheat, which causes the appearance of dry spots on the outside of the leaves. With prolonged exposure to infection, wrinkling of the leaf is added to the main symptoms. The disease spreads instantly, thanks to insects (aphids, ticks, etc.), the development of which becomes the main cause of pepper damage.
Important! Hybrids of the first order are considered the most resistant to mosaic - these are varieties obtained by direct crossing of mother plants. Distinguishing them from the rest of the varieties is not difficult due to the F1 mark.
Late blight on pepper and other nightshade are quite common. This culture is characterized by increased susceptibility to late blight, especially in the second half of summer, when an optimal microclimate is created for its pathogen (cold nights with heavy dew). The fungus affects the entire green mass and is manifested by single or massive putrefactive spots of brown color, on the back of the leaves there appears a light cobwebbed plaque. This infection often leads to the death of bushes.
- excessive moisture;
- growing plants in closed conditions with insufficient ventilation;
- cultivation of previously infected seed;
- crop rotation failure on the site.
Most often, the following drugs are used for this:
- Bordeaux mixture;
- 2% potassium permanganate solution;
- 1% potassium chloride solution;
- soapy water (50 g of soap per 10 liters of water).
Find out what to do if holes appear on pepper leaves.
Alternaria is called a lesion caused by microscopic fungi from the genus Alternaria. The fungus spreads due to wind erosion, rain and insects. The main danger of the disease lies in the fact that it instantly spreads among the stands, and the spores of the fungus can withstand even prolonged frosts. Numerous small and large black spots indicate this disease. Since rot from them often does not stand out, such spots are perceived by many farmers as something natural.
- high temperatures;
- excessive humidity;
- frequent damage to the fruit;
- the use of infected seeds;
- cultivation of plants in contaminated soil.
Cladosporiosis appears, like brown or brown spotting. Its main reason is the development on plants of fungi from the genus Cladosporium. With untimely treatment, the spots affect not only the foliage, but also the stem, as well as the fruits. In the advanced case, the disease leads to the death of individual plants and all plantings.
A combination of such factors leads to damage to the stands:
- high temperature (more than + 25 ° С);
- humidity is about 80% and higher;
- natural instability to cladosporia;
- cultivation of infected seeds;
- neglect of soil sterilization when growing seedlings.
We recommend learning how to deal with pepper pests: aphids, spider mites, caterpillars.
Of these, the most popular are solutions:
- a mixture of polycarbacin (1 tablespoon per 10 liters of water), copper sulfate (1 tablespoon per 10 liters of water) and colloidal sulfur (3 tablespoons per 10 liters of water);
- the drug "Neotec";
- Bravo products.
Black bacterial spotting
The cause of the disease is the aerobic gram-negative bacterium Xanthomonas campestris. Plants at any stage are subject to the pathogen, but young bushes are most often affected by the disease. This infection manifests itself in numerous black spots on the fruits, stem and leaves. With untimely treatment, the disease leads to the formation of large ulcers, with a diameter of 7-10 cm.
- air temperature increase up to + 25 ° С;
- high humidity (about 80% or more);
- damage to fruits and foliage during active vegetation.
Important! If seedlings are affected by bacterial spotting, such plants are recommended to be disposed of. Even in the case of successful treatment, they will be sick throughout the growing season and give a poor-quality crop.
Oidium, or powdery mildew, refers to fungal infections. Its causative agent is pathogenic microorganisms from the genus Uncinula. The disease is spread by air, insects and rain masses. The disease causes black or brown spots, which over time develop into large foci, are covered with a characteristic mold coating. In this case, the foliage dries slowly and curls characteristically.
The causative agent exists in the natural environment freely, but the defeat of pepper is observed upon the occurrence of favorable conditions:
- temperature within + 20 ° С;
- high humidity;
- protracted periods of rain;
- poor site ventilation;
- cultivation of previously infected seed.
Almost all bushes are subject to this disease, regardless of variety. Most often it occurs on young bushes that have entered the fruiting phase.
Most often vertex rot occurs due to irrigation errors. With a lack of moisture, the plants are trying by all means to stock up with freely available water - for this they sacrifice fruits, which become sources of moisture. During this, the fruits fade, which leads to the appearance of dry brown spots on the crown. Over time, they cover all the fruits, which leads to the irrevocable death of the crop.
Additional causes of pathology include:
- an excess of nitrogen in the soil;
- salinization of the site;
- excessively acidic soil.
Pepper bacterial cancer develops as a result of damage to plants by specific pathogenic bacteria belonging to the genus Agrobacterium. With the active development of the pathogen in the tissues of the fetus, the appearance of small black dots is observed, which after a while grow together, forming a dense crust.
To combat bacterial cancer, it is necessary to adjust the water regime of the site. After this, the affected bushes are removed and disposed of, as their fruits become unsuitable for consumption. The remaining plantations are sprayed twice, with a break of 10-14 days, sprayed with 2% solution of copper sulfate.
The best method for combating dangerous pathologies and infections on the site is traditionally considered a complex of all possible preventive measures.
To do this, you must:
- cultivate only rot-resistant varieties purchased from trusted suppliers;
- it is necessary to carry out preplant sterilization of seed;
- sterilize seedlings with the preliminary germination of pepper;
- treat planting material with growth stimulants and other drugs that increase the immunity of plants;
- strictly observe the agricultural technology of growing pepper, including the basic principles of crop rotation;
- create an optimal microclimate on the site, as well as a water regime;
- fertilize the soil qualitatively;
- periodically fight insect pests;
- at least 1 time per month to process plantings with complex means of protection.
Familiarize yourself with the processing features of pepper with boric acid.
Spotting is one of the most common and dangerous pathologies of pepper, which in just a few weeks can lead to the death of all plantings. Pathology can occur for a number of reasons, but the main one is the neglect of the general rules for the cultivation of solanaceae. Therefore, before planting peppers, it is necessary to study the basic requirements of plants, as well as to familiarize yourself with the specifics of growing a crop.