Recognize & fight raspberry diseases

When raspberries have diseases, it can endanger the harvest. We present the most common raspberry diseases with pictures and show countermeasures.

Raspberries (Rubus idaeus) can be grown excellently in the home garden. Unfortunately, the raspberry is not spared from plant diseases either. Surely you have asked yourself the question of what disease your raspberry has. We will show you how you can recognize, treat and prevent these diseases in raspberries.

Crumbly fruity in raspberries

The raspberry is a composite stone fruit. That is, what we call a raspberry is actually a lot of small stone fruits that stick together. The name "crumbly fruity" illustrates very well what this disease is about: the Individual stone fruits no longer stick together and the raspberry falls when picked or stored apart.

Recognize crumbly fruity raspberries

Crumbly fruity can be recognized before harvest by the smaller fruits, which consist of a few stone fruits. The individual stone fruits that make up a raspberry are often thickened. When harvesting, the crumbly fruity is very easy to recognize, as the fruits disintegrate easily when picked.

Combat crumbly fruity

The cause of the crumbly fruity, which is also occasionally described as crumbly fruity, has unfortunately not yet been finally clarified. Insufficient fertilization of the flowers, influences of vegetative reproduction and location factors are suspected of causing this disease. Viruses cannot be excluded as a cause either. As long as the cause of the crumbly fruitiness is not clarified, there are unfortunately no ways to combat it. However, some raspberry varieties are less prone to crumbly fruity, for example 'Prussia', 'Polka', 'Borgund' or 'Zefa 3'.

To prevent crumbly fruity, we recommend that you ensure that your raspberries are supplied with adequate nutrients. It is also conceivable that other diseases weaken the raspberry and promote crumbly fruity. Hence, you should take care to keep your plants healthy overall. The site preparation, possibly with a high-quality potting soil like ours Plantura organic universal soil, as well as suitable fertilization are important elements here.

Root rot in raspberries

Raspberry root rot is an attack on the raspberry roots by the fungus Phytophthora fragariae var. rubi. As a result of the infestation of the roots, the water supply of the plant is disturbed and there is a severe loss of yield up to and including the death of the plant.

Recognize root rot in raspberries

The first symptoms of root rot in raspberries are usually visible from May. In the case of new shoots, leaf discoloration and wilting of leaves and the shoot tip occur. The base of the young shoot often turns dark. In early summer, the first new shoots often die off. Due to an infestation of root rot in two-year-old bearing rods, the shoot is weaker and fewer fruits are formed. Here, too, leaf discoloration and drying of leaves occur. When pulling a rod out of the ground, dark discoloration and the lack of fine roots can be seen. The symptoms are usually first visible in plants in damp locations.

Prevention and control of root rot

Since there is no pesticide against root rot in raspberries, we recommend measures to prevent it from spreading and to get the infestation under control. You should dig up infested plants with their roots as soon as possible and dispose of them in the residual waste. Please do not put the plants on top of the compost, as spores of the fungus may be retained during composting.

The fungal spores can survive in the soil for years. Therefore, raspberries should not be planted for a few years on areas that have already been infested. In another place, as far as possible from the infected soil, you can plant raspberry varieties that are highly resistant to root rot, for example the ’Rubaca variety.

Preventing waterlogging is particularly helpful for prevention. You should therefore avoid compacted or very moist soils as a location. In addition, cultivation on embankments is possible, which also reduces waterlogging.

Rod disease in raspberries

The rod disease is a clinical picture and can be caused by the fungi Didymella applanata,Leptosphaeria coniothyrium or Fusarium avenaceum be evoked. Even Botrytis cinerea (Gray mold) and Elsinoe veneta can cause similar symptoms. These combined diseases of the rod are among the most important diseases in raspberries. The fungus usually penetrates the plant through injuries. An infestation weakens the raspberry, which leads to a reduced yield in the infestation year. In addition, the budding is greatly reduced in the following year.

Recognize rod disease in raspberries

The rod disease, also known as rod death, can be recognized from early summer by purple to black spots on new shoots. The spots often arise first in the leaf axils and become larger and larger over time and can develop into strips that extend over the entire shoot. In late summer, the entire shoot is usually affected, the bark appears black and shines silvery in the light. The leaves of infected branches turn yellow more quickly than on healthy shoots. In addition, the bark begins to peel off the wood.

Preventing and combating rod disease

In order to combat the various pathogens causing rod disease in a targeted manner, it would be necessary to identify the exact pathogen. Unfortunately, this is usually not possible, which is why we advise against using pesticides for rod diseases. Infested rods should be removed as soon as possible and disposed of in the general waste to slow down further spread.

As a preventive measure, we recommend that you avoid an overly dense stand. A good row spacing is 2.5 meters, there should be at least 50 cm space between the plants. Regular weed control also contributes to a well-ventilated stand. In all grooming activities, it is important to avoid injuring the rod. If you cultivate the raspberries with a climbing aid, you should therefore make sure that the rods are not injured.

A need-based fertilization will help you to keep the raspberries healthy. We recommend that you ensure a good supply of potassium and phosphorus when fertilizing. On the other hand, you can keep nitrogen fertilization reduced. A primarily organic long-term fertilizer like ours Plantura organic universal fertilizer promotes fruit formation on your raspberries. It also prevents diseases.

Raspberry Anthracnose

The anthracnose in raspberries is made by the fungus Elsinoe veneta caused. This attacks leaves, shoots and the fruits. An infestation can usually only be recognized at the time of harvest on unevenly tearing fruits, deformed berries and pink spore beds on the fruit. The pathogen overwinters as spores on infected parts of the plant and infects healthy tissue in humid and warm weather.

Unfortunately, pesticides are not available for control. The spread of the disease to raspberries can be reduced by cutting back the infected parts of the plant. As a preventive measure, we recommend a row spacing of around 2.5 meters and a plant spacing of at least 50 cm, as well as good weed control. In addition, you should remove all fruit, including inedible berries, before winter.

Raspberry rust

The raspberry rust is one of the most common diseases in raspberries and is caused by the fungus Phragmidium rubi-idaei caused. The plant is weakened by an infestation and the yield can be reduced. The fungus overwinters on fallen leaves, with the risk of infestation being greatest in May and June when the weather is damp.

The best distinguishing feature of a raspberry rust are the yellow-orange spots or dots on the upper side of the leaf. When the infestation is fresh, orange dots can also be seen on the underside, but they quickly turn black. Once you've identified an infestation, we recommend that you monitor your raspberries regularly and consistently remove any infested leaves. It is best to dispose of the infected leaves in the general waste to prevent the fungus from spreading. There are several synthetic active ingredients available for treating infested plants, such as tebuconazole, azoxystrobin or difenoconazole. Tebuconazole is not considered to be harmful to beneficial organisms, but is suspected of being carcinogenic, i.e. causing cancer. Difenoconazole, for example, has a damaging effect on the useful wood wasps (Trichogramma cacoeciae), whereas the active ingredient azoxystrobin is described as not harmful to beneficial insects and is therefore less of a problem for the home garden. You can avoid the use of such synthetic active ingredients by consistently removing infected leaves and taking preventive measures.

As a prophylactic measure, we recommend that you make sure that the crops are airy and that the leaves dry off quickly. You can achieve this with regular weed control and a wide row spacing. If the plants are infected, the fallen leaves should be disposed of, as the fungus hibernates there.

Botrytis fruit rot in raspberries

Are the flowers or ripe fruits on your raspberries covered in gray mold? Then it is the botrytis fruit rot. This disease is caused by the fungus Botrytis cinerea caused.

Especially in damp weather, the flowers or fruits can quickly be attacked by gray mold. It is spread by conidia spores that get from other infected plants or from the soil to the healthy plant. You should remove the infected parts of the plant as soon as possible and dispose of them in the residual waste. Please do not throw the infected parts on the compost to prevent re-infection. Synthetic pesticides containing the active ingredient fenhexamid are available to treat an infected plant. This is not dangerous for bees, but we recommend that you keep the use as low as possible in order to protect the environment.

We advise you to prevent botrytis infestation. An open stand with good air circulation and a wide row spacing of 2.5 meters is very effective. The fungus penetrates the berry through injuries or through uninjured tissue. Therefore, you should avoid injuries and keep the cells resistant with an appropriate, potassium-rich fertilization. By harvesting completely in autumn, you prevent forgotten or inedible fruits from being attacked, which could lead to an infection in spring. If there is a strong botrytis infestation, we recommend not to grow berries at this location in the following year.

tip: An optimally supplied raspberry with perfect location conditions is more resistant to raspberry diseases. You can find out more about the fact that raspberries need a sunny, airy location with humus soil in our article on the subject Plant raspberries read up. It also describes how extremely important the planting distance is and gives you further tips.