Diseases And Pests Of Roses That We Most Often Encounter. Description, Photo

2023 Author: Ava Durham | [email protected]. Last modified: 2023-11-27 07:13

Despite the abundance of new resistant varieties, the rose is still very sensitive to many diseases and pests. Under certain conditions, some diseases and pests are considered the "scourge" of rose growers, in others - others, but, in general, all roses are subject to the same troubles. Often, the lesion is complex, when several pathogens attack the plant at once. In this article I will talk about the main diseases and pests of roses and for clarity, I will show photos of roses with clear signs of certain diseases or pests.

Content:

• Rose disease
• Rose pests
• How to deal with rose diseases and pests?

Rose disease

1. Gray rot

Gray mold is one of the most common problems when growing roses. It is found everywhere. It is especially pronounced in varieties with light color of the petals. It affects the whole plant - from the root collar to the buds.

For the first time, gray rot can be seen in the spring after removing the shelter. It manifests itself on the stems in the form of brownish rotten shoots. Later - in the form of elongated brown spots growing from top to bottom. Small brown specks initially appear on the foliage, which later spread throughout the entire leaf blade.

On the petals of flowers, the disease manifests itself in the form of light spots, which quickly grow, darken, dry out. The affected buds do not bloom - they pupate. In some varieties, rot appears on the petals of flowers in the form of red dots.

2. Marsonina, or black spot

Another common rose disease. It is often confused with peronosporosis, but it is very easy to distinguish black spot - its rounded spots have a radiance. Appearing on the upper side of the leaves, they are at first single. Then there are more and more of them. They grow in diameter (up to 5-15 mm) and gradually merge with each other.

Affected leaves turn brown, crumble - flowering bushes are prematurely exposed. Because of this, the wood does not mature, new buds are not formed, and in winter the plants freeze slightly.

3. Peronosporosis, or downy mildew

It manifests itself on the leaf apparatus in the form of red-brown or purple small spots with an indistinct shape, which, depending on the type of rose, can either be concentrated along the central veins of the leaf, or be located along the entire leaf plate. On the back of the leaves, in place of spots, a mealy bloom appears. It happens that a clear yellow edging is outlined around the spots, which means that the leaf will soon fall off.

With a significant lesion, the disease manifests itself on young shoots - red-brown spots appear, cracking of the bark is observed.

4. Powdery mildew

Everyone has probably encountered this disease. It manifests itself on young foliage and stems with buds. First, in the form of separate spots, similar to a powdery bloom. Then - in the form of a solid white bloom.

Gradually, the plaque becomes more and more dense, gray - small black fruiting bodies of the wintering stage of the pathogen are formed in it. The affected buds dry out, the plant loses its attractive appearance.

5. Phyllostic spotting

Phylostic spotting is caused by several pathogens and therefore can manifest itself in slightly different ways. In one case, scattered rounded spots appear on the leaves of a rose, limited by an expressive wide border of purple-brown color. Over time, the center of the spots turns ash gray, but the border remains.

In another case, the edging of the spots has a crimson tint. Damaged leaves turn yellow and fall off prematurely.

6. Purple spot

It appears on the upper side of foliage in the form of many small, purple, often almost black, rounded spots, sometimes forming purple stripes. Over time, the color of the spots changes to gray, but the crimson hue does not disappear. On the underside of the foliage, you can find merging brown spots. The affected leaves fall off, the flowers remain underdeveloped.

7. Rust

Rust damage can often be found on standard varieties of roses. Separate rounded spots without bordering appear on the leaves. Over time, numerous orange pustules form on the back of the leaf on the spots. At the base of the shoots, cracks often appear, from which spores appear in the form of a yellow dusty powder. Gradually, shallow brown ulcers form in these places.

8. Pestalonia

A new disease for us, brought from foreign rootstocks. Until recently, it was believed that the disease manifests itself exclusively in greenhouses, but every year it can be seen more and more often in the open field.

At the edges of the leaves, brown spots appear, growing towards the middle (a characteristic feature), with yellow edging spots, on which grayish sporulation pads of the fungus form over time. The affected foliage turns yellow and dries up prematurely.

9. Drying of branches

The problem is caused by a number of pathogenic fungi. Most often, this can be a manifestation of an infectious burn, cytosporosis, tubercular necrosis of the cortex, tracheomycotic wilting, and common cancer.

10. Bacterial cancer

One of the most dangerous diseases of roses. It enters the plant organism through mechanical damage. It manifests itself in the form of tuberous growths that can form on the roots, at the base of the stems, branches. The growths are small at first, but quickly grow and harden. Over time, they rot.

The disease greatly inhibits the plant, inhibiting its development. Over time, the bush will inevitably die.

Rose pests

In addition to diseases, insects also harm roses. There are about 50 species in total. Among them are leaf-gnawing, and sucking, and mining, and even gall-forming pests. However, the most harmful are rosaceous aphids, thrips, rosaceous downward sawfly, golden bronze, shaggy bronze, common spider mite.

1. Rose aphid

Rose aphid lives in colonies. It settles on buds, peduncles, young shoots. By sucking the sap, it drains the plants. Severely affected bushes develop poorly, form twisted shoots. In places where insects accumulate, a sticky coating forms. The buds of affected roses often do not open, but simply dry up.

2. Thrips

Very small pests (1-2 mm). They can be gray, brown or black. They feed on the cell sap of plants, also damaging the leaves and petals of roses. The damaged leaves are covered with very small discolored dots and haircuts. Damaged flowers have an untidy edge of the petals, small spots along the edge, and a slight torn.

3. Rosy downward sawfly

The larva is harmful as it passes through the period of development inside the tops of young shoots and peduncles. As a result, in the spring, the tops of the shoots suddenly wither, turn black, dry out. If you cut off such a shoot in the place where wilting begins, you can see the course of the pest.

4. Golden bronze

A fairly large (up to 20 mm) beetle with a golden-green color. For roses, it is especially unpleasant because it damages the buds, trying to get to the stamens and pistils, gnaws at the petals, because of which they either do not open at all or open an incomplete flower. But not only adult beetles do harm, but also larvae. They, developing in the soil, gnaw at the roots of plants, which is especially harmful to young rose seedlings.

5. Bronze Shaggy, or Shaggy Olenka

A small (up to 12 mm) black beetle covered with grayish hairs and characteristic white spots. Like the golden bronze, it damages the buds, eating away the stamens, pistils and rose petals.

6. Common spider mite

Very small, invisible pest (body length 0.25-0.43 mm). It is very harmful in greenhouses, but it is also rare in the open field. It feeds on the sap of young plant tissues. Weaves a thin cobweb. The damaged leaves brighten and dry out.

How to deal with rose diseases and pests?

Diseases and pests of roses can manifest themselves throughout the garden season. Moreover, insect larvae and fungal spores tolerate winter well and, with the onset of heat, immediately begin their destructive activity for roses. Moreover, it is in the spring, when roses come out of hibernation, actively increase the leaf mass and form buds, that they are most sensitive to diseases and pests.

Therefore, experienced rose growers must carry out preventive spraying of roses in the spring, trying to prevent the appearance of diseases and pests. The market offers a large number of both biological and chemical preparations for these purposes, which can be bought at almost any garden store.

Spring preventive spraying of roses is needed and works - first of all, they give roses the opportunity to enter the flowering period strong and healthy. But they only restrain the spread of diseases and pests, without completely destroying them. And, for sure, during the season there will be a need (perhaps more than once) to combat this or that disease or pest.

May your roses be beautiful and healthy!