I have been growing raspberries for 30 years, I can get stable crops. For those who are just mastering gardening, I want to talk about the causes of yellowing of leaves in the midst of the season. This chlorosis is an insidious disease, it is difficult to immediately determine the causes of the disease. Eliminate them in different ways. 
Source: frukti-yagodi.ru
Depending on the form of the lesion, treatment is chosen. The pigment in the leaf blades emerges due to a lack of chlorophyll. The reason can be viral or physiological, as the bush claims a lack of macronutrients, primarily iron.
A disease always arises unexpectedly. This is not connected with the vagaries of the weather. By the way, if you arrange an ice shower in the midst of hot days, the sheets turn pale, but under the sun in three days they will return to normal. Worse if a wiry pattern is clearly manifested on the plates. First of all, dense tissues turn yellow. If the leaves of the buttocks suddenly began to turn pale or yellow, this indicates raspberry chlorosis
There is a massive loss of landings and a single. Yellowness on the leaves is a bright, but not the only symptom of chlorosis on raspberries. They become smaller, shoots grow worse. When the rampant disease falls on budding, trouble. There will be no harvest. The ovaries will be stunted, crooked. They will quickly dry out. Sugar content in them will not be, one acid.
The danger of raspberry chlorosis
It is not difficult to recognize chlorosis in a timely manner, and not every gardener can determine the cause of the lesion. Non-infectious is easy to eliminate, and fighting infectious is difficult. I admit that if before harvesting at least two weeks, at the first sign of yellowing, just in case, I carry out preventive treatment against viruses. During the ripeness of the berries I try to apply mechanical methods. Doing nothing is dangerous.
An infection that disrupts the synthesis of chlorophyll is not afraid of frost. If you do not take action, there will be a relapse in spring, then goodbye, berries!
The causative agents of the disease are insects. The virus, falling through the leaves, penetrates the roots of the bush. The plant begins to languish before our eyes. I immediately throw out such bushes so as not to infect neighboring raspberries. I spill the soil with potassium permanganate. If this is not done, the whole plantation will die in a couple of years.
Types of raspberry chlorosis: causes, symptoms
The virus usually occurs sporadically. Usually on extreme bushes of raspberry rows. Large age leaves are affected, on them you can see the traces of aphids or thrips. Viruses live in symbiosis with these insects, develop inside them, are sown with excrement.
Aphids are spread by black earth ants, they must be destroyed!
Thrips creep on their own. Against them, effective treatment is the treatment of Bordeaux liquid on a green cone. If, nevertheless, the sucking "guests" have come, urgent measures are needed.
As chlorosis manifests itself, it can be:
- yellow veins and mesh on the leaves;
- yellowed spots drying up from the edges;
- tips of spotted leaves twisting into a tube.
Depending on the immunity of the raspberry, the symptoms appear in a pronounced or mild form. Sweet thermophilic varieties are more susceptible to pathogens, zoned varieties are more resistant. 
Non-Infectious, Viral
Physiological chlorosis can occur with an excess of deoxidants in the soil, for example, after liming the soil, making ash. When raspberries are flooded, although this is a moisture-loving culture, grows on the banks of rivers, does not like stagnant water - the roots cease to transfer nutrients due to excess mineral salts.
Non-infectious lesion manifests itself in different ways, depending on the lack of a macro or microelement:
- yellowing, drying along the edges, and then the death of the leaves occurs with a lack of nitrogen;
- with young greenery, the leaves look paler than the rest: the bushes lack iron;
- poor growth of young shoots and the appearance of yellow spots throughout the leaf, indicates a deficiency of magnesium;
- with damage to old leaves, in the petiole region and its gradual yellowing to the tip - a lack of boron;
- if only adult sheets between veins are discolored - manganese deficiency.
Treatment of different types of raspberry chlorosis
Physiological forms are eliminated by foliar top dressing - iron sulfate. I breed it, as it is written on the bag, then I double the volume of water. I spend processing with a spray gun or a broom. For better adhesion, add liquid laundry soap up to 100 ml per bucket in vitriol. When there is green soap, it is added twice as much.
The old method is to close rusty cloves or other pieces of iron at the roots. I haven’t tried it myself, but the neighbors say it helps. If there is no vitriol, other chelates are used - substances containing iron. 3-4 treatments with an interval of three days - and order. Raspberries come to life.
With a lack of nitrogen, spraying with a solution of 1 tbsp will help. urea in 10 liters of water. But you need to do this better a month before the berries ripen.
Foliar top dressing is good to do in any case, 2-3 times a season, it increases fruiting and sugar content. To do this, dissolve 10 g of boric acid in 10 l of hot water.
Manganese is replenished with manganese chelate, magnesium with magnesium sulfate.
For prevention, it is necessary in the early spring and autumn to feed raspberries with a complex fertilizer.
The fight against the viral form lasts for months. With a weak infectious lesion, first of all, you need to remove the affected leaves. Agronomists recommend supporting diseased raspberries with potassium - this fertilizer improves immunity. With a severe defeat, diseased bushes are burned. And the rest are treated with special means.
Preparations against chlorosis:
- Topaz at a concentration of 0.05% (you need to breed according to the instructions), carry out processing during budding or after picking berries, the drug is toxic;
- Fundazole 0.1%, raspberries are sprayed from early spring to flower stalks, in autumn, the remedy is not so effective.
Many cultures are susceptible to chlorosis, so the treatment of the berry should not be delayed.
Chlorosis resistant raspberry varieties
I will list the zoned varieties that grow on our site and are quite stable:
- Collective farm worker - raspberry large berries are sugar-rich;
- Progress - a repairing variety, pleasing with harvest until late autumn;
- Hussar is the most unpretentious species;
- The yellow giant - raspberries have never been ill either with me or with my neighbors;
- Kuzmin's news - if it grows in a dry place, it will not hurt;
- Gigantic - bushes do not affect aphids, thrips, sweet berries.
With proper care, spring prevention forget about chlorosis. But if suddenly yellowness appeared, you need to treat the plants immediately.
