Dahlia diseases and their treatment

Dahlias were the decoration of the temples of the sun god, and were used by the ancient Aztecs and Mayans for pagan religious rites. The first name of the dahlia is "acoctiles". The current name appeared only in 1803. At present, dahlias are used as adornment of homestead territories. Most flower growers are passionate about breeding dahlias. And this is easy to explain - the flowering of these plants is distinguished by its beauty. But dahlias need care. To a greater extent, gardeners are bored with harmful insects and viruses, due to which diseases of dahlias appear

In this material, we will tell you which harmful insects and viruses are most susceptible to dahlia flowers, and how to deal with them.

Dahlia diseases: prevention of infections

Dahlia diseases: photos

Tubers are treated with fungicides or sulfur. You can spray the ends of the tubers with medicine or make a solution (drug + water) and dip the roots into it. If the fungicides are in liquid form, then the nodules should be kept in the medicine for 15 minutes. Chemical treatment is carried out with rubber gloves. After the tubers are processed, dry them. How to do it? We spread the nodules on something paper (newspaper, cardboard) or on a wooden one. In order to avoid confusion in the varieties, it is necessary to carry out preventive measures in turn - from one variety to another.

Do not dry nodules on concrete surfaces. The concrete will draw out the water, because of this, the nodules may shrivel ahead of time. If there are several varieties of dahlias in stock, then prepare several containers containing the solution. Place one variety in each container, you will definitely not get confused. To treat plants, some gardeners prepare solutions from fungicides and systemic insecticides. The nodules that float up during immersion are thrown away, because later they will die.

Preventive measures against diseases of dahlias are required depending on the climatic conditions in which the flowers will be cultivated. If the climatic conditions are humid, then there is an increased likelihood that fungal diseases will manifest themselves, and if the climate is dry, then the fungus will not appear at all.

Types of diseases of dahlias and the fight against them

Dahlia diseases: photos

Dahlias can be affected by various diseases; cases of fungus are frequent. The fungus appears in humid climatic conditions and in the event that the planting of plants is dense.

Dahlia disease - leaf spot

The causative agent of this disease of dahlias is the mushroom Entyloma dahlia. Symptoms: the appearance of specks of yellow-green color on the leaves. Subsequently, they become blurred and stained in a gray-brown color with a very prominent border. Spotting occurs due to poor air passage between the bushes due to the fact that the flowers are densely planted. Treatment is carried out with fungicides. Preparations: Oxyhom, Fundazol. The processing of healthy bushes is carried out, and the diseased flowers are destroyed.

Dahlia diseases: photo of leaf spot

Gray rot (Botrytis)

The causative agent of this disease of dahlias is the pathogenic fungus Botrytis cinerea. Symptoms: specks of brown color appear on the leaves, and then the entire plant is affected. The leaves dry up, the buds dry out, the peduncles are deformed.

Dahlias are also prone to gray rot when they bloom. On the baskets you can see blurry specks, because of them softening of tissues and rotting of flowers occurs. The disease appears due to the fact that the growing area is waterlogged, and this occurs after the dense planting of plants.

Treatment is carried out with fungicides. Preparations: Topsin, Fundazol, Benleit, Rovral.

Verticillium and furious wilting

The signs of diseases of dahlias are identical, but the pathogens are different: Verticillium dahlia, Fusarium oxysporum. First, the root system and nodules are damaged, and they rot. Then the leaves and apical fragments of buds and shoots wilt. The infected flower covers a pinkish bloom (fusarium) or brown (verticilliasis).

The reasons are the same: air does not pass between plants, moisture accumulates in excess due to dense planting of flowers. Infected nodules are removed and burned. Preventive measures - treatment with systemic fungicides. Preparations: "Oxyhom", "Fundazol".

Dahlia diseases: photos

Dahlia diseases: brown rot

The causative agent of this disease of dahlias is the mushroom Rhizoctonia solani. The disease affects young shoots and flowers that are at the very beginning of the growing season.

Dahlia disease appears due to the fact that the nodules are unnecessarily deepened into the ground. Prevention and treatment are carried out with fungicides. Preparations: Fundazol, Alirin, Fitosporin-M, Gamair.

Diseased flowers are removed. But that is not all. The soil contains the causative agents of this disease. Therefore, the planting area must be disinfected. It is necessary to cover the soil in large quantities with garden lime. In the future, it is strictly forbidden to plant dahlias in this place.

Dahlia incurable diseases

Dahlia diseases: photos of affected flowers

There are some diseases of dahlias, from which plants cannot be cured.

Mosaic disease.

On the leaves, stripes of pale green or yellowish color appear. If these signs are found on a bush, immediately dig it up and burn it. This procedure will protect other bushes. The threat of defeat will be reduced to the minimum level.

Tuberous galls.

The root collar is covered with nodular warts. The infected tuber is immediately dug up. There is another way: at the end of the period, you can save the nodules - to trim the diseased fragments. After cutting, the cut is treated with fungicides. But it is still recommended to burn the infected nodules, and not plant plants on the affected area for a year.

Fusarium.

Brown specks appear on the stems. Dahlias wither and die. Affected shoots are cut and burned. The rest of the bushes are processed, for example, 0.1% Bordeaux mixture or 0.1% foundation.

Mycosis.

The manifestation of this disease is compared with the usual lack of moisture - yellowing of flowers and wilting of shoots occurs. Therefore, first, watering the beds is carried out, it is necessary to follow the plants. If the leaves are restored in a day, it means that these were symptoms of a lack of moisture, and if, on the contrary, it means mycosis. The disease does not respond to treatment, the infected bush is dug up and burned. For the next four years, it is forbidden to plant anything on the affected soil.

Dahlia diseases: video

Dahlia diseases and pests. Control methods

There are a large number of harmful insects affecting the dahlia.

Aphids (Aphididae).

These harmful insects can be seen with the naked eye. Symptoms: the leaves turn yellow and become curly, sticky discharge appears on them.These enemies are carriers of other infections.

If there is only one aphid colony, then we simply cut it off along with the leaves. If there are a large number of colonies, then the flowers are processed. Medicines: green soap solution, insecticidal preparations - "Aktara "," Fitoverm "," Confidor "," Decis ".

Chrysanthemum and strawberry nematodes.

Leaves, cuttings, buds are damaged. On the leaves, first light, then darkening necrotic spots appear. Nematodes can survive the winter in the buds of the nodules. There are also root nematodes. Symptoms: the bush lags behind in growth, and in the future, the stems are bent.

Flowers infested with nematodes are dug up along with a large lump of soil and burned. Cultivation of plants that may be attacked by nematodes is prohibited on this site. Preventive measures - watering the soil with the drug "Ecogel», It is a strengthening agent for flower walls. Nematodes are afraid of marigolds, which means we plant them next to dahlias and other vegetation that may be exposed to these pests.

Vegetable bugs.

They suck out nutrients from the leaves of dahlia flowers. For this reason, there is a violation of the current of the batteries. Symptoms: the affected leaves are covered with specks of yellow color, turning brown over time. Subsequently, the leaf tissues wrinkle and break.

If you find the appearance of pests on flowers in a timely manner, then treat them with a solution of green soap. If the lesion is massive, more radical treatment measures are required, for example, drugs "Iskra-M"," Mospilan". In the morning, the insects hardly move, which means that we process the bushes just in the morning.

Scoop-gamma.

Moths appear in the last spring days and in the first summer. They drink nectar without harming the plants. But butterflies are harmful by laying a large number of larvae, from which caterpillars hatch later. So they are pests. Caterpillars gnaw at the roots of flowers at the surface layer of the soil; later on, dahlias can simply wither.

If a small number of caterpillars have bred, then you can collect them with handles. But if there are a lot of them, then drugs go into battle: “Bitoxibacillin», «Lepidocide", Insecticides Fufanon, Iskra-M. With these drugs, it is necessary to process the plants and the soil under them.

Gastropods (slugs).

They manifest themselves in shady places, more often with high humidity outside, and are very active at night. They gnaw through the furrows in the leaves. More often they just eat the leaves.

Scatter ashes between the rows that irritate these pests. This, of course, is ineffective, because after the ash gets wet, it no longer poses a danger to slugs. To destroy them, you need a simple crushed red pepper and superphosphate. Also, slugs die from metaldehyde preparations scattered on the ground. You can set slug traps and collect them by hand. An abomination, but preserving dahlias is still more important.

Greenhouse whitefly.

Small butterflies, 0.1 cm in size, occasionally come across on flowers that are planted in open soil. They tend to attack dahlias in greenhouse conditions. Laying of larvae occurs on the inner side of the leaflet. These pests are hiding under the leaves of flowers, they have found a shelter, it is called. Eggs eat on leaves, which causes specks to appear on the leaves. Cocoons are also formed on the leaves. It turns out that the leaves for whiteflies are home. Fight them with insecticides. Preparations: "Iskoriy "," Aktara "," Mospilan "... They are sprayed with dahlias.

Deer (furry bronze).

This beetle is black in color, more than 1 cm in size. It gnaws at pistils, stamens, petals. It attacks dahlias from the last spring days to the last summer days.The laying of the larvae is carried out in the soil saturated with humus, where the brown-headed larvae of white color hatch, feeding on the roots of flowers and the remains of plants. As a rule, there are few beetles themselves, they just need to be collected, and the larvae are destroyed when the soil is loosened.

Summary.

If you take proper care of dahlias, then nothing will amaze them, and no one will attack them. Well, if it happened, use this material and find out how to overcome the disease of dahlias. All in your hands.

Dahlia diseases: fight and treatment