Raspberry leaves turn yellow in summer: what to do and why this happens

Yellowing, drying out and falling of leaves in autumn is a natural process indicating that the plant is entering a dormant state. But if such signs are absolutely normal for autumn, then a yellowing crown in spring or summer is a serious problem.

The condition of the plant's leaves determines how comfortable it is. The appearance of yellow spots indicates improper care, a deficiency of nutrients, or infection with diseases and pests. Let's look at why raspberry leaves turn yellow in summer and what to do to save them.

Reasons for yellowing of raspberry leaves in summer

Yellowing of raspberry foliage in summer or spring is not natural. The condition of the bush is judged by the color of the leaves. Yellow and dry spots are often the result of:

• lack of nutrients;
• improper care;
• diseases;
• pest attacks.

In most cases, if the cause of yellowing leaves is eliminated, it is possible to save raspberries. If the problem is running, you will need transfer And pruning damaged part of the bush. If the plant has completely shed its leaves and its shoots have dried out, it means it has died. In this case, the bush cannot be restored.

Sometimes yellowed leaves indicate that the bush is infected with a viral infection. Viruses cannot be cured. To save healthy plants, the affected ones will have to be removed from the site.

Nutritional deficiencies

Deficiency of micro- and macroelements leads to improper plant development. The appearance of the leaves determines which substance is missing.

Note! If the fertilizer application schedule is followed, problems with a lack of nutrients do not arise.

With a lack of nutrients, yellowed leaves appear in the summer, usually in June or July. Their appearance depends on the type of deficiency:

1. Nitrogen. With an insufficient amount of nitrogenous fertilizers, the development of the plant slows down and its growth stops. The substance is responsible for photosynthesis, so its lack leads to shredding, paleness and yellowing of the green mass. To save the plant, it is fed with nitrogen-containing agents, for example, ammonium nitrate.
2. Sulfur. Its deficiency is expressed in uniform blanching and then yellowing of the leaves. Over time, the petioles become thinner and fall off.
3. Iron. Iron deficiency is called chlorosis. Outwardly, its symptoms are very similar to those of jaundice, a viral disease. With chlorosis, the leaves first turn pale green and then pale yellow, while the veins remain green. For treatment, preparations containing iron are used, for example, iron sulfate.
4. Magnesium. With a lack of magnesium, the leaves turn yellow, wither, dry out and fall off prematurely. At the same time, spots appear in the center of the leaf plate, the edges turn yellow and curl. To get rid of the problem, apply magnesium fertilizers, for example, magnesium sulfate.
5. Calcium. When it is severely deficient, the edges of leaves and shoots become brown and die. If the problem is not very advanced, white or light yellow stains and stripes appear on the leaf plates.
6. Bor. With its deficiency, small dry spots appear, which gradually increase in size.Hollowness of shoots is observed. Yellowed leaves appear that quickly dry out. Boron deficiency often occurs due to a lack of potassium.
7. Zinc. Gray-yellow spots appear on the leaf blades. Their number increases rapidly and they merge. The greenery is crumbling.

There are two ways to combat the lack of nutrients. The first option is to use only the substance that the plant needs. To do this, it is important to correctly identify the type of deficiency, since an excess of some substances is also dangerous. An easier way is to use complex fertilizers.

Diseases

Another reason why raspberry foliage turns yellow is disease. Most infections kill the plant without timely treatment; some are not treated at all. When one plant is infected, the infection is quickly spread by wind and insects to other crops.

Diseases are most effectively treated in the early stages. The more advanced the infection, the higher the likelihood of raspberry death.

Infectious chlorosis

Viral chlorosis is also called raspberry jaundice. Symptoms of the disease resemble iron deficiency. The problem is identified by the following signs:

1. Yellow leaves appear on young growth and two-year-old branches. On the shoots, the leaves at the top suffer the most. In this case, at first the veins on the yellow leaf plate remain green, but then they also turn yellow. The foliage gradually becomes smaller, but its shape does not change.
2. Shoots, fruit petioles, stalks, sepals, and fruiting brushes acquire a yellow tint. Annual shoots stretch out and become weak.
3. The berries of the affected plant also change - they become smaller, become less juicy, and have an unexpressed taste.

Symptoms are most pronounced at the time of fruit set and ripening., and after harvesting the crown turns green and the signs practically disappear. The disease makes itself felt again in the fall. The next year everything repeats itself.

Viral disease cannot be cured. If its signs are detected, the raspberries are dug up, taken away from the site and burned.

To prevent infection, follow the rules of prevention:

1. Choosing healthy planting material. It is better to choose varieties with resistance to jaundice.
2. Timely prevention and elimination of pests. The bushes are regularly inspected and treated with products to combat aphids and spider mites, which contribute to the spread of the disease.
3. Sanitary pruning. Remove shoots that thicken the crown, dry and old branches, and parts of the plant with damaged bark.
4. Compliance with the schedule for applying mineral and organic fertilizers. This boosts the raspberry's immunity.
5. Raspberry planting in an area where the same crop grew no less than 5 years ago.

Root cancer

Root cancer is also called root goiter. This is a bacterial disease that is provoked by a dry climate, alkaline soil, and long-term cultivation of shrubs in the same place.

Bacteria enter the plant structure through cracks in the roots. Growths with a diameter of 10 to 12 cm form on the root shoots. Sometimes they also touch the root collar. Galls (as the growths are called) have an irregular shape, at first they are soft, then gradually harden.

Due to root canker, the roots stop fully absorbing liquid from the soil.. The plant begins to suffer due to a lack of nutrients: the leaves turn yellow, wither, dry out, new shoots develop poorly and become short, the fruits become smaller and lose moisture.

Advice! To make sure the diagnosis is correct, dig up the raspberry roots and check for growths.

Root cancer cannot be cured. Affected plants are dug up and burned. The soil on the site is treated with copper sulfate to prevent infection of other plants. Other shrubs cannot be planted in a place that has been affected by the disease for 3 years. It is better to plant it with lupine to improve the soil.

To avoid infection, before planting, treat the soil and roots of the planting material with copper sulfate. In the fall, the garden is cleaned. Be sure to check the acidity of the soil.

Rust

Rust is a fungal disease. Carried by coniferous trees and some weeds. Fungal spores are especially active in warm and humid weather.

Symptoms of rust:

1. In the second half of spring, the inner side of the leaf blades is covered with small red pads with spores. Small yellow spots form on the outside.
2. Gradually, the spots and pads with spores increase in size.
3. The pads burst and spores come to the surface. Some of them cover the entire lower surface of the leaves, the other part scatters throughout the garden.
4. Leaves infected with rust dry from the edges to the center.

The productivity of the raspberry bush decreases, the fruits become tasteless. The winter hardiness of the plant is significantly reduced.

Fighting methods:

1. The most affected leaves, which have already begun to fall asleep and are covered with a thick spore layer, are torn off.
2. The plant is treated with fungicides (Topaz, HOM) according to the instructions.Typically re-treatment is required at intervals of 2-3 weeks.
3. To prevent the disease, before the buds bloom, the bush is sprayed with a solution of copper sulfate (1 tablespoon per bucket of water) or Bordeaux mixture.

Ring spot

Ring spot is another viral disease. Its first signs appear a year after the raspberry is infected.:

1. Pale yellow or yellow-green ring-like patterns appear on the leaves. This usually happens in the first half of summer. At the end of July - August, the signs often disappear, but by autumn they appear again.
2. The bush or individual shoots lag behind in development. The branches become short and brittle and die quickly.
3. The fruits are undeveloped and dry out quickly. Sometimes, against the background of the disease, new ovaries begin to develop in the fall.

The disease cannot be treated. The affected raspberries are dug up, removed from the site and burned. To prevent the appearance of ring spot, varieties resistant to it are grown and only healthy plants are planted. The soil is treated against nematodes, possible carriers of the disease.

Late blight

Late blight is a fungal disease that affects the roots of raspberries.. For a long time the disease practically does not manifest itself. Only in advanced stages does the foliage quickly turn yellow, and soon the bush dies.

To treat the disease, water the soil around the raspberries with a solution of copper sulfate. or fungicides diluted according to instructions. In this case, folk remedies are ineffective, since the disease makes itself felt in the later stages of development. To prevent infection, preventive treatment with copper sulfate is carried out.

Curly

Leaf curl is a viral disease that can kill an infected plant within 3 years. The disease is recognized by these signs:

1. The leaves become hard and small, deformed, and look wrinkled. The underside becomes brown.
2. The leaves turn inward. This makes the plant look curly.
3. The berries turn out sour and dry, and are deformed.

Bushes affected by curling cannot be treated. These raspberries are dug up, taken away from the site and burned.

Pests

Pests often cause yellowing of leaves. Typically, this effect occurs when attacked by insects sucking juice from greens.

Aphid

These small insects settle in whole colonies on young shoots and leaves of raspberries.. They come in green, brown, gray and black. There are individuals with and without wings.

Aphids suck the sap from the plant. Affected leaves wither, turn yellow, dry out and fall off. It is easy to detect the pest by examining the raspberries.

To get rid of aphids, the affected shrub is treated with insecticides. (“Karbofos”) or folk remedies:

1. Soap-ash solution. A grated piece of laundry soap and 1 kg of ash are dissolved in a bucket of water. The product is allowed to brew for a day, then used for spraying. It is recommended to water the soil around the bush.
2. A decoction of bitter herbs: wormwood, dandelion greens, yarrow.
3. Onion-garlic solution. Grind 0.5 kg of onion and 0.2 kg of garlic in a meat grinder. The pulp along with the peel is poured with a bucket of water and left for 3 days. Then the affected plants are filtered and sprayed.

Spider mite

Another pest is the spider mite. These are small insects that are black, green, yellow or red..

Advice! To spot mites, look at the underside of the leaves. On them you can see a cobweb containing pest larvae.

Affected foliage curls inward, turns yellow and fades.

Fight spider mites like aphids. Use insecticides or folk remedies.

Agrotechnical errors

Although raspberries are a hardy and unpretentious shrub, violation of agricultural practices affects its condition. The problem arises with improper care, incorrect selection of a site for planting, or unfavorable climatic conditions.

Agrotechnical errors causing yellowing of leaves:

1. Bush thickening. This error causes poor air exchange, insufficient supply of nutrients, stagnation of moisture on the leaves, which provokes yellowing of the foliage and fungal infection. Annual sanitary and formative pruning and maintaining a distance of at least 1.5 m when planting will help avoid the problem. When the bush thickens, thin out the crown, removing all branches directed inward and root shoots.
2. Lack of moisture. In this case, the leaves begin to turn yellow and fall off. In dry summers, raspberries are watered once every 1-2 weeks, spending 10–30 liters of water per bush. Mulching the tree trunk circle will help reduce the number of waterings and reduce the risk of fluid deficiency.
3. Increased soil acidity. Slightly acidic soil suits raspberries. If acidity levels are elevated, add dry alkali or ash at the rate of 1 kg per 1 m².
4. Excess moisture. The problem often occurs during periods of prolonged rainfall. Mulching the soil and watering it with a solution of copper sulfate will help save the plant. Excess liquid often leads to leaching of useful substances. In this case, additional fertilizer will be required.

How to save raspberries

If the raspberry leaves begin to turn yellow, it is first of all important to check the bush for diseases and pests.. Even if there are no obvious signs, several preventive treatments are carried out with copper-containing preparations (copper sulfate solution).

If there are no signs of illness, review care. It is important that the soil around the bush does not dry out, but that the liquid does not stagnate. The soil is mulched. The plant is fed with complex mineral fertilizers. After a month, add organic feeding.

Attention! The reasons for the yellowing of remontant and simple raspberries are the same. However, plants that produce 2 harvests per year most often suffer from nutrient deficiencies. After harvesting the first harvest, comprehensive fertilizing is required.

If all care conditions are met and no signs of disease are detected, but the raspberries have turned yellow anyway, the bush is replanted after first inspecting the roots. Another way to save the plant is to carry out anti-aging pruning.

Preventive measures

To prevent premature yellowing of raspberry leaves, it is important to create optimal conditions for it. Prevention rules:

1. Selection of healthy seedlings. Before planting, they are inspected for traces of diseases and pests: spots, holes, cracks in the bark, distortions, growths on the shoots and root system.
2. Disinfection of seedlings, soil and garden tools. Preventative treatments solution of copper sulfate in the spring before the buds open and during the rainy season.
3. Timely watering, mulching the soil to prevent moisture stagnation.
4. Fertilizer application at least 3 times a year. Usually raspberries are fed in spring, summer and autumn, before wintering.
5. Formative and sanitary pruning. Cutting out root shoots.
6. Autumn garden cleaning. Remove and burn fallen leaves and other plant debris.

Conclusion

Premature yellowing of raspberry leaves is a dangerous symptom that indicates improper agricultural practices, a lack of micro- and macroelements, and infection of the bush with diseases and pests.

To cope with the problem, the plant is carefully inspected for traces of diseases and insects, and proper care is checked. After this, all possible causes are eliminated.