Content
White spots on raspberries most often appear in hot weather. If they are only noticeable on the berries, it is most likely just due to drought, so there is no need to worry. If spots appear on the foliage, this may indicate the spread of infection or pest invasion. Therefore, urgent measures need to be taken.
Description of the problem
White spots often appear on raspberry fruits, not only on ripe ones, but also on unripe ones. They cover the berries partially, in fragments, from a certain side. In this case, there are no signs of illness - the problem is due to the temperature being too high. The bush should be protected from the sun and watered abundantly.
If white spots also appear on the leaves, this indicates a disease or the appearance of pests. The most common causes are white spot (septoria) and spider mites. You can cope with them using folk remedies, biological and chemical drugs.
Why do raspberries turn white on one side?
If white spots on a raspberry appear on only one side, and the bush looks healthy, the reason is most likely due to hot weather.But if there are other signs, for example, white cobwebs on raspberry leaves, this indicates the appearance of mites. The causes may also be related to diseases, such as white spotting.
Heat and drought
Hot weather is one of the main reasons that is difficult to influence. In many regions of Russia in the summer, daytime temperatures exceed 30 degrees for several days or even weeks in a row. Combined with the lack of rain, this factor has a bad effect on almost all crops.
As a result, raspberries turn white when ripe. Moreover, the surface of the fruit does not lighten entirely, but only in parts, which is associated with the destruction of the coloring pigment. This phenomenon is called drupe spots. The fruits lose their attractive appearance, but remain completely edible.
If the berries are partially whitened, they are still edible
Agrotechnical errors
If the raspberries are white inside, this may also be due to a violation of the care rules. The raspberry bush is unpretentious, but requires regular watering. Water is given intensively at the moment of setting berries and at the initial stage of fruiting. White spots may appear due to lack of nutrition. It is periodically necessary to apply fertilizer containing the main elements - nitrogen, calcium, potassium and phosphorus.
Diseases
Among diseases, the main cause of light spots is white spotting.
Septoria is a fungal infection that can affect not just one raspberry bush, but several plants at once. The disease leads to leaf drop and reduced yield.The pathogenic fungus mainly overwinters directly in the tissues of the shoots and, less often, in the foliage. Activated in summer. The provoking factor is excessive watering and humid air.
Main stages of development:
- first, brownish spots appear on the leaves;
- then they become white;
- a dark border is formed along the contour of problem areas;
- the damaged parts die off, which leads to the death of the leaf blades.
Spider mite
If the raspberries turn white, this may also be due to the appearance of spider mites. This is a dangerous pest that can settle on a wide variety of crops, including fruits and berries. The tick body is small, not visible to the eye (up to 0.7 mm in length). Main signs of infection:
- a dense web that covers raspberries;
- white or brownish spots on the leaves (on the inside, but can also extend to the outside);
- young foliage curls;
- the buds begin to dry out.
At the moment of their appearance, mites do not pose any particular danger - only individual leaves can die because of them. But as a result of the active activity of insects, the leaf plates will become covered with white spots, and the entire ground part of the bush will suffer, which will inevitably affect the yield.
What to do if there are white spots on raspberries
If raspberries turn white, you can help them in different ways. The cause needs to be diagnosed. If white spots cover only part of the fruit, while the entire bush looks normal, then the cause is related only to drought.
The problem can only be solved through prevention. In hot weather, raspberry bushes are given water at least once a week; in the late evening you can sprinkle water on the crown. An additional measure is to mulch the roots with sawdust, straw, grass clippings or other natural materials.
Since pigmented areas can appear due to improper care, the main preventive measure is to follow the rules of agricultural technology, including:
- Application of fertilizing (saltpeter or urea in spring, during fruit set - superphosphate and potassium salt or complex mineral fertilizer).
- Periodic loosening of the soil.
- Installation of supports. They will allow the bush to take the correct shape, which will provide maximum access for ventilation.
- In hot weather, it is recommended to install a sun awning. This will protect the bush itself, as well as the soil, from overheating.
- If necessary, trim off all affected branches and leaves.
- In mid-autumn, clean the raspberry tree trunk, removing all fallen leaves.
If the cause is related to spider mites, white spots appear on the raspberry leaves, and the berries themselves may be covered with a small cobweb.
Pest control measures depend on the stage of plant development
Before the fruiting period (spring, early summer), a single treatment with chemicals can be carried out as a preventive measure:
- "Fufanon";
- "Anti-mite";
- "Acrex";
- "Dimethoate";
- "Decis".
At the berry ripening stage, it is best to use biological preparations, for example:
- "Fitoverm";
- "Vertimek";
- "Akarin";
- "Bitoxibacillin."
If the invasion is not very strong, and the raspberries have already formed, you can cope with the cause of the appearance of white spots using folk remedies. According to the experience of summer residents, the following infusion recipes help best (the quantity is given based on a standard 10 liter bucket of water):
- garlic cloves – 400-500 g;
- dandelion – 200 g roots;
- tobacco dust – 200 g;
- wood ash – 200 g.
If white spots appear due to septoria, you will need to treat with a fungicide:
- Bordeaux mixture;
- "HOM";
- "Tsihom";
- "Skor";
- "Topaz";
- "Ordan";
- "Maksim".
It is also advisable to use the products before fruiting. If the berry has already formed and white spots appear due to septoria, spraying is carried out a maximum of a week before harvest. Raspberry bushes are processed in the late evening or early morning. It is advisable to do this in dry and windless weather.
Regular watering and fertilizing will ensure not only the absence of spotting, but also a good harvest.
Conclusion
White spots on raspberries can appear for various reasons. You can influence almost every one of them. The easiest way is to follow the basic rules of care, especially watering, mulching and fertilizing. In mid-spring, it is recommended to carry out 1-2 preventive treatments against the appearance of diseases and pests.
