A variety of diseases and plant parasites can cause quite serious damage to the garden rose, sometimes leading to the death of a flower crop. Before starting the treatment of roses, one should not only clarify the damaging factors, but also find out how the most effective fight against them is carried out. It should be noted that roses are sick not only with non-infectious, but also with many infectious diseases, so you should start fighting the lesion as soon as possible.
Infectious diseases of roses
The optimal arrangement of flower culture in the infield and adherence to growing technology significantly reduces the risk of rose infectious diseases.
However, even the most resistant varieties are not immune to disease damage in adverse weather conditions, as well as low light, thick plantings and poor ventilation. Also, this popular decorative culture often suffers from mechanical damage., which may be the "gateway" for the penetration of fungal, viral or bacterial infections.
|Type of lesion||Disease name||Signs of defeat|
|Fungal infections||Powdery mildew||A very characteristic white, powdery coating appears on the foliage and stems.|
|Rust||The appearance of very typical, orange-yellow staining of spores on the shoots and lower leaves|
|Black spotting||The formation on the foliage of purple-brown, blackening over time, rounded spots, falling leaves, slowing down the development of shoots and loss of frost resistance|
|Infectious burn||The formation of brown spots in the early spring with reddish-brown fringing on the shoots of roses|
|Gray rot or botritis||In wet weather, the buds and pedicels are covered with a clearly visible gray coating|
|Bacterial infection||Bacterial burn or stem cancer||The leaves curl, dry out, and the bark acquires a pronounced brown color and dies.|
|Viral infection||Band virus||The formation of dark coloring of the edging along the contours and veins of sheet plates|
|Bronze||The appearance of whitish spots on the foliage and brightened leaf veins|
|Viral wilt||Deformation of leaves on the bush, sprouting shoots and the complete absence of buds|
|Viral necrosis||The appearance of spots of necrosis on leaves that darken and then massively fall|
|Mosaic of crescent||Appearance of round necrotic spots and chlorosis on foliage|
Noncommunicable Rose Diseases
As a rule, non-infectious rose diseases are the result of gross violations of growing technology. Improper agricultural practices, including non-compliance with irrigation and top dressing, often cause non-infectious lesions of rose bushes. Most often, problems are associated with a violation of the diet of decorative culture.
Rose Disease: Treatment
|Malnutrition||Signs of illness||Preventive and therapeutic measures|
|Nitrogen deficiency||Foliage loses its green color, red dots appear, and leaf blades become very narrow||Dressing a decorative plant with a solution of urea or ammonium nitrate at the rate of a tablespoon per bucket of water|
|Excess nitrogen||The foliage acquires a dark green color, the growth of the aerial part to the detriment of flowering is enhanced, the resistance to damage by fungal infections decreases||Reduce the use of nitrogen-containing fertilizers|
|Phosphorus deficiency||Violet-brown staining of the strip and spots is formed at the edges of the foliage, shredding of the foliage and stunting growth are observed||Feeding roses with a solution of superphosphate at the rate of a tablespoon per bucket of water|
|Potassium deficiency||Yellowing of the foliage, and further wrinkling and the appearance of reddish-purple staining of the leaves||Plant nutrition with a complete complex fertilizer with a high potassium content, diluted at the rate of a tablespoon per 10 liters of water|
|Excess potassium||Weakening of the aerial part of the plant, the death of peduncles, stopping the development of the root system of the plant||Feeding rose bushes with calcium nitrate|
|Magnesium deficiency||The formation of discolored spots on the leaves||Top dressing of ornamental culture with a complete complex fertilizer with a high magnesium content, diluted at the rate of a tablespoon per 10 liters of water|
|Lack of iron and manganese||Damage to bushes with chlorosis, resulting in yellowing and discoloration of the leaves||Spend a couple of foliar dressings. Spray the aerial part with iron-containing preparations. You can treat the plant with 0.5% manganese sulfate|
|Boron deficiency||The shoot growth point dies, the foliage is deformed, the edges of the leaves are bent||Close up wood ash in the soil around rose bushes|
When choosing the method of fertilizing and the composition of top dressing, it is important to remember that an excess of nutrients can inhibit the growth and development of roses, so the main dressings are carried out no more than twice a year. Experienced agronomists recommend the first treatment and top dressing of rose bushes after winter, in the initial phase of the growing season. The second top dressing is preferably performed at the end of summer using full mineral fertilizers. Weakened by improper care and depleted by pathogenic microflora, roses often die during the wintering process.
As a rule, the main treatment consists in the correct and timely use of modern, most effective drugs. Plants should be sprayed in dry, preferably slightly sunny weather, which will allow the active substance to effectively combat the damaging factor. Important to remember, that some ailments, including streak virus, rhesus mosaic virus, viral wilting, and bacterial cancer, cannot be treated, therefore it is recommended to scoop up and destroy bushes affected by these diseases.
|Type of lesion||Used drug or remedy||Treatment regimen|
|Fungal infections, including powdery mildew and rust||Iron sulfate, potassium sulfate, colloidal sulfur, Benomil, Tsineb and Fundazol||Spraying in autumn or early spring with a 3% solution of iron sulfate with the addition of a 0.3% solution of potassium sulfate or Bordeaux mixture. Twice a month, treat the aerial part with a copper-soap solution or 1% suspension of colloidal sulfur or replace them with 0.25% Benomil, 0.4% Tsineb or 0.1% Fundazole "|
|Black spotting||Modern drugs "Profit", "Ridamil-gold", "Topaz" and "Skor"||Processing the aerial parts of the plant with solutions, alternating the preparations: Profit, Ridamil-Gold, Topaz and Skor|
|Botritis||Any antifungal insectofungicidal agents||Processing the aerial parts of the plant with Fundazole, Benlat and Teldor, as well as spilling the soil around the bushes with a solution based on the Maxim preparation|
|Necrosis of the cortex||Bordeaux mixture, the drug "Abiga peak"||Spraying the aerial parts before foliage blooms with Bordeaux liquid, a solution based on the Abiga Peak preparation or its substitute|
|Ramulariosis, cercosporosis and phylostictosis||Preparations based on the active substance mancozeb or triazole||Alternating treatment of the aerial parts of the plant with Profit, Ridomil Gold, Topaz and Skor preparations at the dosage recommended by the manufacturer|
Despite the fact that the work of domestic and foreign breeders in recent years is aimed at breeding not only highly decorative, but also disease-resistant varieties, only the correct prevention of rose diseases allows you to get the most decorative, abundantly flowering and long-lasting plant. Preventive measures are as follows:
- splashing water during irrigation measures on foliage is one of the main reasons for the development of fungal diseases, therefore it is necessary to water rose bushes exclusively under the root;
- the plants do not need a significant amount of nitrogen-containing complexes, and the excessive introduction of nitrogen often causes an increase in the susceptibility of the ornamental culture to disease damage;
- good prophylaxis of powdery mildew lesions is soda treatment, which should be carried out twice a week with a solution based on a teaspoon of soda, diluted in a bucket of water;
- as prevention of damage by gray rot, manganese top dressings are used, which increase the plant's resistance to this fungal infection;
- in order to prevent damage to the most common fungal diseases, it is necessary to remove fallen leaves in a timely manner and conduct relatively deep soil treatment around the bushes, followed by spilling with a solution based on the Maxim preparation;
- it is necessary to regularly remove and destroy all parts of rose bushes affected by diseases.
Rose Pests: Fight
For flower growers, especially beginners, it is very important to remember that in order to reduce the risk of hurt roses and pests, it is necessary to use an exceptionally clean garden tool, as well as conduct regular visual inspections of the bushes to quickly detect the first signs of infection.