Contents
Raspberry leaves curl – gardeners usually face such a problem in late spring and summer. The deformation of the plates can be caused by several reasons, among which are improper care and exposure to infections and insects.
Why do raspberry leaves curl?
Diseases, poor growing conditions, or pest attacks can lead to leaf deformation in raspberries. To understand exactly why the plates are curling, you need to carefully examine the bush.
Lack of minerals
If there is no plaque, no spots, no traces of insect activity on the raspberry leaves, but the plates are still twisted, the problem is most likely a lack of nutrients. Especially often the shrub suffers from a lack of:
- nitrogen – with a deficiency of this element, the development of raspberries slows down;
- potassium and phosphorus – with a lack of minerals, the endurance of the plant decreases, the shrub absorbs other nutrients from the soil worse;
- iron – the leaves usually not only curl, but also turn yellow, although the veins often remain green.
Feeding raspberries for good growth is recommended from early spring. For the first time, fertilizers are applied immediately after thawing the soil. At the first feeding, it is better to use ammonium nitrate or urea, as well as wood ash.
In summer and closer to autumn, shrubs can be fed with complex potassium-phosphorus mixtures.
Lack of moisture
During dry periods, raspberries can suffer from lack of water. The roots of the shrub are located close to the surface and do not reach the deep layers of the soil, in which moisture can remain. In the absence of rain and watering, the leaves of the plant often curl, change color and begin to fall off.
In dry weather, it is recommended to moisten raspberries at least once a week. On average, from the end of spring to the beginning of autumn, 7-8 waterings are carried out for the plant.
Diseases
The leaves of the shrub curl due to viral and fungal diseases. Ailments interfere with the normal nutrition of the plates, provoke deformations. Ultimately, leaf tissues are destroyed, the raspberry crown crumbles ahead of time.
Chlorosis
Chlorosis of raspberry leaves is non-infectious and viral in origin. In the first case, it is caused by sudden temperature changes and an excess of nitrogen in the soil, in the second case, by pathogens that penetrate tissues through damage to roots and shoots. Against the background of chlorosis, the production of chlorophyll in the required quantities is disrupted, the leaves curl up and turn yellow.
An ailment of non-infectious origin can be eliminated with the help of complex dressings and spraying with iron sulfate. If chlorosis is viral, then raspberries can only be removed from the site, since there is no treatment in this case.
Chlorosis is reflected in the fruiting of raspberries and leads to crushing and drying of berries.
Curly
Viral curl of raspberries, as the name suggests, causes the leaves of the shrub to curl, dry out at the edges and darken. The shoots stop growing and thicken, the yield drops, the berries become watery and tasteless.
It is impossible to cope with curliness, the affected raspberries need to be dug up and burned. Neighboring shrubs are then sprayed with fungicides to prevent the spread of aphids – this parasite is a carrier of the virus.
Curly raspberry leaves often develop with high humidity and insufficient ventilation of the bushes.
Rust
The fungal disease is manifested by a bright orange tuberculous rash on the underside of raspberry leaves. Over time, the plates twist and massively fall off, the shoots of the shrub weaken and become thinner.
Rust fungus quickly spreads throughout the site. When the first symptoms occur, it is necessary to remove all affected parts of the plant and treat the raspberries with copper sulfate or Bordeaux liquid. If the bush is not affected too much, then it is not necessary to destroy it entirely, it may well recover.
Spraying against rust is carried out 2-3 times with an interval of two weeks
Fungal anthracnose
Anthracnose often affects raspberries in acidic soil and with a lack of phosphorus and potassium. The disease manifests itself as brown spots on the stems and leaves, with time the marks become purple. The plates curl and dry, and then begin to fall off. On the branches of a shrub with an advanced disease, ulcers appear with a dark rim around the edges, the bark becomes coarse and cracks.
The fight against anthracnose is carried out with the help of Quadris, Abiga-Peak and similar fungicides. Spraying is performed according to the instructions several times at two-week intervals.
Anthracnose fungus develops at high humidity and a temperature of about 22 ° C
Mučnistaâ rosa
In conditions of high humidity, raspberries in the area are often affected by powdery mildew. You can recognize the disease, first of all, by a whitish coating on the plates, as the disease develops, the leaves curl and dry out. With a strong defeat, the yield of raspberries drops up to 50%, the growth of new shoots is reduced.
The disease responds well to treatment in the early stages; Topaz, Fitosporin-M and Thiovit Jet can be used to get rid of powdery mildew. It is necessary to cut the raspberries and remove the affected shoots.
In the early stages, powdery mildew can be easily rubbed off with a finger, but becomes thicker over time.
vermin
Raspberry leaves curl when the shrub is damaged by pests. Insects draw juices from the plant, as a result of which the plates are deformed and quickly die.
aphid
The insect breeds in large colonies and can densely stick to whole raspberry shoots. Under the influence of the pest, the plates of the shrub curl up, acquire an unnatural sheen, and then dry out and fall off. Most often, aphids attack raspberries in July and August in hot and humid weather.
With a weak lesion, you can get rid of the pest with a solution of laundry soap or ash. If there are a lot of insects, it is better to use industrial insecticides – Karbofos, Aktellik and others.
Aphids carry mosaic and curl viruses, which further weaken raspberries
stem fly
The pest affects raspberries most often in mid-May. The insect lays its eggs in the axils of the leaves, the hatching larvae begin to feed on plant sap and gnaw through passages inside the shoots. Shrub plates twist and change color, young branches begin to rot.
To eliminate the stem fly, insecticides Iskra and Karbofos are used. As a preventive measure in autumn and spring, they carefully dig up the soil under the bushes, since some of the larvae hibernate in the ground.
Raspberry shoots affected by the stem fly are cut to the ground
Loads and waves
Raspberry leaves curl under the influence of the weevil, which becomes active in late April or May when the soil warms up to 10-15 ° C. Damage to the culture is caused by both adult insects that feed on the juice of plates and larvae. When affected by a weevil, raspberries slow down in development. The insect lays eggs in the buds of the plant, so the culture begins to bloom and bear fruit worse.
You can eliminate the weevil by spraying with insecticides. In the spring, the shoots must be inspected daily and, if necessary, manually collect beetles. If the insects managed to lay their eggs, then the damaged buds must be cut and destroyed.
Raspberries often suffer from weevil in close proximity to strawberries and strawberries
What to do if raspberries curl leaves
If the raspberry leaves are curled, then the first step is to spray with preparations containing copper – vitriol or Bordeaux liquid. These solutions have a good effect on most fungal diseases and strengthen the overall hardiness of the shrub. With the obvious presence of pests on the shoots, it is necessary to carry out the treatment with an industrial or home insecticidal solution.
If visually the shrub is in order, but the leaves are still curling, it is worth reviewing the watering and fertilizing schedule. Raspberries need to be urgently fertilized with complex minerals, watered abundantly and loosened the soil. In the future, it is required to carefully monitor the level of soil moisture and its composition.
Prevention
Often, the leaves of raspberry bushes curl when it is too late and pointless to treat the crop. Priority should be given to prevention, namely:
- carefully inspect seedlings before planting and do not use plants with damaged roots and shoots;
- in spring and autumn, carry out a sanitary haircut and thinning of the bush;
- regularly feed raspberries with complex minerals containing potassium, nitrogen and phosphorus;
- spray plantings with Bordeaux liquid, starting in early spring.
An important step in prevention is maintaining cleanliness in the garden. In autumn, all plant debris in the raspberries is removed. Fungi and pests that cause leaf curl usually overwinter in the soil.
During the autumn loosening of the soil, fungal spores and larvae appear on the surface and die during frosts.
Conclusion
Raspberry leaves curl, usually under the negative influence of pests and fungi. Less often, a pronounced lack of moisture or nutrients in the soil leads to deformation of the plates. To maintain the health of the shrub, you need to follow the rules of agricultural technology and devote time to disease prevention.
