Content
Raspberry chlorosis is caused by a decrease in the concentration of chlorophyll in the leaves, as a result of which their color changes to yellow. The cause of pigment deficiency can be either a lack of iron or infection with a virus. In the first case, coping with the problem is quite simple, in the second, all that remains is to get rid of the affected bushes. There are no drugs effective against viral raspberry chlorosis yet.
What does raspberry chlorosis look like?
The main symptom is leaves that have turned yellow much earlier than expected. The leaf blade may turn pale completely, or yellow “veins” are clearly visible on it on a green background.
If nothing is done, there is a strong slowdown in the rate of development of raspberry bushes affected by chlorosis
Varieties
Depending on the cause of development, there are two main types of chlorosis.Less dangerous for raspberry bushes is what is called physiological or non-infectious (non-viral). In this case, by yellowing of the leaves, the plants “signal” about a deficiency of nutrients in the soil. In most cases, they lack iron, less often - manganese, boron, zinc. The situation is aggravated by the gardener’s mistakes in care or the wrong choice of planting location. Raspberry chlorosis can be caused by a lack of sunlight and regular waterlogging of the soil.
Non-infectious raspberry chlorosis does not require any treatment. You just need to identify and eliminate the “destabilizing” factor (adjust watering, carry out appropriate fertilizing), and the condition of the plants will return to normal by itself.
If the problem occurs repeatedly, treatments with biostimulants are recommended.
Carbonate or alkaline raspberry chlorosis is sometimes considered a separate variety. It is caused by planting bushes in alkaline soil that is unsuitable for them (the crop also does not like the increased acidity of the soil, but it tolerates it better). It is obvious from the photo that the symptoms of carbonate and non-infectious raspberry chlorosis are identical. Its treatment consists of restoring the optimal soil pH for the crop (5.8-6.7). Excess alkali prevents them from properly absorbing nutrients.
Infectious raspberry chlorosis, caused by several different strains of viruses, is much more dangerous for bushes. Characteristic symptoms may appear stronger or weaker, depending on the variety, plant immunity and cultivation conditions.
There are no effective means to combat infectious chlorosis yet.
Why is chlorosis dangerous?
Any type of disease disrupts one of the most important processes for any plant - the production of chlorophyll. It is vital for photosynthesis, during which carbon dioxide is converted into oxygen and nutrients by sunlight.
As a result, raspberries are not able to provide themselves with everything necessary for normal development, reproduction and ripening of fruits. The growth of bushes slows down greatly, shoots and leaves begin to gradually die off.
The virus is not afraid of frost, so a relapse of the disease is inevitable in the spring. Non-infectious chlorosis greatly “suppresses” the immunity of bushes, and other problems gradually “join” it.
Raspberry chlorosis develops quite slowly, but after 2-3 seasons the bushes will die
Causes
In the vast majority of cases, the development of non-infectious raspberry chlorosis is the fault of the gardener himself, who chose a place for planting without taking into account the preferences of the crop or made serious mistakes in care. Bushes most often “pick up” the virus from insects that carry it and feed on plant juices (aphids, thrips, raspberry flies).
However, the gardener himself can contribute to infection with the virus. This occurs due to neglect of disinfection of garden tools and tools.
The virus is “sown” on raspberries along with pest excrement
Symptoms
The main symptom is yellowing of the leaves (the entire plate or the appearance of spots or “mesh” on it).He is accompanied by:
- shrinking leaves;
- elongated and thinned shoots, drying tops;
- dry, deformed berries, easily falling apart into individual drupes, practically tasteless or very sour;
- root rotting;
- “massive” shedding of leaves, buds, fruit ovaries;
- gradually drying leaf plates that curl into a tube.
You can’t expect a high-quality harvest from the affected bushes
Non-infectious chlorosis, depending on what macro- or microelements the raspberry lacks, manifests itself in different ways:
- Iron. The opening young leaves are initially lighter than the others; they quickly turn completely yellow.
- Nitrogen. The leaf blades turn yellow from the edge to the center, and at the same time a dry “border” forms along the edge.
- Magnesium. Blurry yellow spots are scattered chaotically on the leaves.
- Bor. Yellowness spreads over the entire leaf from petiole to tip, with the oldest leaf blades being affected first.
- Manganese. Only the tissues between the veins turn yellow.
How to treat raspberry chlorosis
A viral disease, even at an early stage of development, cannot be treated. Only bushes affected by its physiological variety can be saved.
Treatment of raspberry chlorosis with iron sulfate
The most common cause of non-infectious raspberry chlorosis is iron deficiency. To “compensate” for the deficiency, carry out 2-3 foliar fertilizing with iron sulfate at intervals of 3-4 days, diluting it according to the manufacturer’s instructions.
To enhance the effect, iron chelate is prepared from iron sulfate. Dissolve 5 g of citric acid in 2 liters of hot water (50-60 °C), and then add 8 g of iron sulfate. The liquid is intensively stirred, and a flaky sediment often forms in it. The finished product is cooled and used for foliar feeding.
For better “sticking”, you can add a little small shavings of green potassium or laundry soap to the solution, whipping it into a foam
Drugs
You can purchase ready-made iron chelate in the store. In addition to it, the deficiency of this microelement is compensated by other drugs.
Ferovit
Contains iron chelate in high concentration. This is a very effective stimulator of the process of photosynthesis and cellular “respiration” of plants. It is suitable for the prevention and treatment of non-infectious raspberry chlorosis.
The drug Ferovit can be used to protect indoor plants, garden ornamental and fruit-bearing crops from chlorosis
Brexil Fe
A drug specially created for the prevention and control of chlorosis on fruit and berry crops. One foliar feeding of raspberries is enough.
Brexil Fe is part of a series of preparations containing microelements necessary for raspberries (iron, calcium, magnesium, manganese) in the form of chelates
Orton Micro-Fe
Universal fertilizer for indoor plants and garden crops. Contains not only iron chelate, but also other microelements necessary for raspberries during chlorosis in an easily digestible form.
Fertilizing raspberries with Orton Micro-Fe has a positive effect on plant immunity
other methods
An ancient folk remedy for preventing and combating raspberry chlorosis is to bury a small rusty nail under each bush when planting. Rust is iron oxide, which gradually “passes” into the soil and is absorbed by raspberry bushes. Therefore, such a remedy will be quite effective and long-lasting.
The only serious drawback of the folk method of combating raspberry chlorosis is that you can “disturb” the nail during loosening, and then stumble upon it.
A similar result can be obtained by scraping off rust from somewhere and scattering it over a bed of raspberries. However, such a procedure will have to be carried out annually to prevent and combat chlorosis.
Raspberry varieties resistant to chlorosis
There are no raspberry varieties that are guaranteed not to become infected with the virus. However, there are those who resist the disease much more successfully than others.
Kuzmina News
Vigorous bushes with weakly branching shoots that bend under the weight of berries and need staking. The variety is early ripening, cold-resistant, medium-yielding (1-1.5 kg per bush). The weight of the berry is 2.5-3 g, the shape is blunt-conical, the taste is pleasant, sweet and sour, with a light spicy aftertaste.
Raspberries Novosti Kuzmina firmly adhere to the stalk even after ripening and are distinguished by good transportability
Collective farmer
Mid-season, frost-resistant, high-yielding variety. The bushes are spreading, the shoots are strewn with thorns.The berries are large (2.5-3.5 g), elongated-cone-shaped, with a balanced sour-sweet taste.
Kolkhoznitsa raspberries retain their characteristic taste and do not “fall apart” into individual drupes even after heat treatment
Hussar
A very unpretentious variety that tolerates drought and frost well. The shoots are powerful, erect, tall (up to 3 m), and do not require garter. The berries are conical, very large (10-12 g). The taste is distinctly sweet, with a slight sourness.
The high yield of Gusar raspberries (5-7 kg per bush) is ensured by the arrangement of fruit branches along the entire length of the shoots
Preventive measures
Simple prevention will help minimize the risk of developing raspberry chlorosis:
- selection of varieties with good resistance to the pathogen;
- providing the bushes with the necessary “living space”;
- refusal to place beds in lowlands, planting raspberries in “heavy” soil;
- preliminary check of soil pH;
- regular loosening and weeding of beds;
- application of complex fertilizers during the season to maintain plant immunity;
- Immediate treatment of raspberries with insecticides or fungicides if suspicious symptoms are detected.
Raspberries affected by viral chlorosis should not be spared. The bushes are uprooted and burned. You cannot put them in a compost pit or simply “store” them on the site. In the place where the bushes grew, the soil with raspberry chlorosis requires disinfection by any means. Most often it is shed with a 3% solution of copper sulfate or Bordeaux mixture.
Conclusion
Having discovered raspberry chlorosis on the bushes, it is important to understand what caused the yellowing of the leaves and the appearance of “associated” symptoms.If the lack of chlorophyll is due to iron deficiency, restoring the healthy appearance of the bushes is quite easy - you just need to provide them with the necessary microelements. Infectious chlorosis caused by a virus cannot be cured with modern means, so attention must be paid to its prevention.
