If the apricot tree is to be in full bloom and survive the winter, you need to protect it from one of the numerous diseases. Prunus armeniaca is one of the most delicate fruit trees you can grow. Not only do they need a lot of care, they also need a suitable location and regular pruning to prevent illness. It is important to know which diseases can affect the apricot tree.
Apricot tree: 10 typical diseases
Due to its sensitivity, the apricot tree can be afflicted by a multitude of diseases, which in the worst case can even lead to the death of the wood. The reason for this is the fact that Prunus armeniaca is originally from an area that is not the ideal Properties for the intensive development of bacteria, viruses and fungi, as is the case in Central Europe is. Even with ideal care, the trees are still susceptible to the ten diseases presented below. However, there are a few ways you can make the apricot tree more resistant to possible disease if the location is adapted:
- sunny
- warm
- protected from moisture by precipitation
In addition to site optimization, it is also possible to choose a resistant variety. The problem with apricot, however, is the fact that there is no variety that is immune to each of the diseases. Some varieties are more resistant to a specific disease than others. For this reason, you need to check which apricot diseases are prevalent in your area and plant appropriate varieties.
Tip: If you're wondering what the difference between apricots and apricots is, you'll be amazed that both names refer to the same fruit. The apricot is called apricot in Austria, South Tyrol and southern parts of Bavaria and for this reason it is not a different species.
Rubber flow
The rubber flow is one of the most common apricot diseases, which presents itself mainly in the humid regions of Germany. Gum flow is a physiological disorder that can either occur alone or accompany a disease. It is characterized by the following symptoms, which are very easy to recognize:
- gummy liquid leaks out
- this happens with shoots and branches
- either colorless or like amber
Rubber flow occurs due to a liquefaction that affects individual parts of the wood and decomposes them until it then emerges and forms the characteristic rubber bodies. Since the flow of gum is not a single disease of the apricots, but a concomitant phenomenon, it is not always certain what causes it. Therefore, you will need to look for or review your care for any of the diseases below to be able to effectively counter the flow of gum. Failure to combat the flow of rubber will result in the following problems:
- blocked ducts
- Nutrient and water supplies are cut off
- Branches and shoots die off
- whole tree dies
The flow of rubber becomes particularly bad when there is a longer dry season or when it is particularly warm. Since the apricot tree loses a lot of moisture as a result and can no longer transport liquid via the ducts, intense drying out occurs and the apricot tree dies. You can slow down this problem a little if you remove the infected shoots and twigs and dispose of them in the general waste. Then you should examine the apricots for possible diseases or care errors and take appropriate treatment measures.
Powdery mildew
Powdery mildew is not uncommon in Germany when you are cultivating an apricot tree. Since Erysiphaceae can occur on numerous native and naturalized plants, the apricot tree is also not protected from this and is usually even worse affected. Powdery mildew can be recognized on apricots when the leaves and young shoots are covered with a white coating that appears mealy. The mushrooms have an easy job if the apricot tree does not have enough fresh air and there is permanent moisture in the crown. The following measures will help against powdery mildew if it affects your apricots:
- Remove infected parts of the plant
- do not dispose of on compost
- Dispose of in residual waste
Fungal infestation is prevented by regular clearing cuts in the treetop, as the fungi have a lot of leeway in this. If too much nitrogen is given to the tree via the fertilizer, this can also increase susceptibility to mildew infestation. In combination, these two variants work very well against the fungi, but you should always keep an eye out for them. It can also help if the soil is well loosened so that the fungi cannot spread easily. Neem-based preparations can also be injected if you have access to them. This is particularly recommended as a direct control measure.
Note: You can try using home remedies to control powdery mildew if the infestation is not that severe. This is especially recommended if the tree is still young and would suffer from a cut.
Black sooty mildew
Black soot is a disease that does not really damage the apricot tree. It is caused by a pest infestation and is a side effect. The reason for this is the already weakened apricot tree, which is an easy target for the mushrooms. Black sooty mildew is usually triggered by a scale or aphid infestation and can therefore only be treated if you take action against the pests. The fungus can be recognized by the following symptoms:
- Time: late summer
- Upper side of the sheet covered with black spots
- can be very large
- Leaves slowly wither
- Honeydew recognizable
Since the apricot tree can no longer carry out effective photosynthesis due to the black spots, the leaves slowly die off, but this does not really harm the apricots. In addition to combating pests, you should take preventive measures to strengthen the apricots. This works effectively against the pests and the fungus.
Bacterial burn
If the bacterial fire attacks your apricot tree, there is nothing you can do about it and you have to slowly foster your specimen over a longer period of time. The disease can be recognized, triggered by the bacterium Pseudomonas syringae pv. morsprunorum, from the following symptoms:
- Leaf margins become blotchy
- Leaves slowly die off
- more resin is excreted
- Fruits become blotchy
- The bark shows clear indentations (cortical necrosis)
- in extreme cases, entire branches die off
These symptoms are similar to those of shotgun disease and should not be ignored. Since there are no direct remedies for this disease, you need to use preventive measures that will strengthen your apricot tree and, in this way, slowly get it back on its toes. This includes:
- liming (trunk white)
- Use sprays containing copper
- Carry out careful cutting measures
- just thinning out
- avoid wounds
There is nothing more you can do in this case.
Shotgun Sickness
As explained in the previous section, some symptoms of shotgun disease overlap with bacterial burn. Above all, the numerous leaf spots are to be mentioned here, those caused by the Wilsonomyces fungus carpophilus look like the leaves have been shot with a shotgun been. Other symptoms are:
- Spot color: red, brown
- Spots turn into holes
- increased leaf shedding
- Shoots become blotchy
- Shoots begin to wither
- Fruits blotchy
- Spots sink into the pulp
- are outlined in red
- dry up or rot until they are dropped
The only direct measure against this fungus is to remove infected shoots. Here only cut into healthy wood, no further. Then apply special preparations against the disease. These are based on the following ingredients:
- copper
- Network sulfur
- Clay
To prevent further infestation, plant garlic (bot. Allium sativum) and onions (bot. Allium cepa). These work effectively against the fungus in the soil.
Note: Since shotgun disease is particularly common in years with a lot of rain, you should ensure a sheltered location. The leaves just can't stand too much rain.
Sharka disease
One of the most dangerous diseases that can affect your apricots is sharka disease. Due to its high risk of infection, it is notifiable and cannot be combated directly, but it can be prevented. The first signs can be seen from mid-May. The damage caused by the Sharka virus (PPV) is as follows:
- Leaves show rings of olive green color
- Rings turn into black spots
- The apricot peel becomes pocky
- gummy pulp
- Red color
- premature fruit shedding
The viral disease is notifiable due to its intensity. It can ruin entire crops and shouldn't spread to the neighborhood. If you recognize an infestation, you should act immediately and remove the tree completely and then burn it. Unfortunately, it is not enough to remove the infected areas, the virus is still retained. Only clearing and burning are effective. For prevention, fight any aphids that have chosen your apricot tree as these transmit diseases. This can also happen through already infected apricot tree fissures. For this reason, you should only plant healthy pieces and choose robust varieties if possible.
Frizziness
One of the fungal diseases that could attack your apricot tree is curl disease. This is caused by the fungus Taphrina deformans and can be clearly recognized by the damage:
- leaves that grow frizzy
- littered with vesicles
- Vesicles colored red or green
- Shoots or entire branches can perish
- weak bloom
- Harvest yield decreases sharply
In itself, the curl disease is not fatal for the apricot tree, though
it is dealt with and precautionary measures are taken for the next season. However, the infestation can no longer be prevented if you can already see the first, curled leaves. Remove all affected parts of the plant and dispose of them in the residual waste to prevent the fungus from spreading. With a little luck, the fungus will stop spreading after the cut. This is prevented with the following measures:- Plant protected from rain
- Inject preparations (containing copper) in January
- Use plant strengtheners in spring
- Remove dead plant parts
- collect existing fruit mummies
- Burn fruit mummies
A very important point of prevention is removing wet leaves in autumn. This is the ideal basis for the fungi to spread and must therefore be completely removed. If this step is not taken, the apricot tree will fall ill in most cases and you will have to accept another season without the delicious fruits. Do as much as you can to stop the fungus from spreading.
Note: If you cannot plant your apricot tree under a roof or some other form of rain protection, stretch a waterproof tarpaulin over the tree during heavy and prolonged rainfall. In this way, the basis for an infection is removed from the fungus.
Monilia peak drought
Another of the numerous fungal diseases that your apricots can suffer from. Monilinia laxa attacks your apricots and causes a crop failure, as the flowers and shoot tips in particular suffer from it. The infection by the fungus always occurs in early spring, when it is damp and cold and flowers have already formed. The fungus enters the plant via the flowers and causes the following symptoms:
- Shoot tips of 20 to 40 cm in length affected
- Leaves wither
- Flowers wither
- Fruits wither at a young age
- The fruits take on a brown color
- don't fall off
- Fungal spore stores of gray color are formed
- Rubber flow visible
Unfortunately, nothing really can be done about the Monilia peak drought, other than completely removing the infected parts of the plant. It is best to cut back the entire shoot until the healthy wood is reached. As long as these parts have been removed, the infestation should be averted. Here, too, either dispose of the infected parts of the plant in the residual waste or burn them. Before a new shoot takes place, use a means to strengthen the plant. This means that your apricot tree is better protected from numerous diseases.
Verticillium wilt
As the name suggests, this is a disease caused by the fungus genus Verticillium. It is one of the deadliest diseases for your apricot tree and is caused by the long-standing settlement of fungi in the soil at the location of the trees. Since they can stay there for up to 15 years, you have to choose a good location and provide the right soil properties. The withered fungi clog the trees' nutrient and waterways, which leads to the following symptoms:
- Leaves wither
- Shoots, branches and twigs follow
- Tree dies over a period of several years
Since the process is slow, an infestation is sometimes not even noticeable in the first few years. Be sure to collect any leaves that fall off during this time. You should also remove the autumn leaves to prevent the mushrooms from spreading further. Remove all infected shoots and dispose of them in the general waste or burn them completely. It is only trimmed down to the healthy wood, without leaving stubs.
Valsa disease
When the valsa or toad skin disease hits the apricots, all you have to do is remove all of the affected parts of the plant to contain the infestation. This disease can be recognized on the apricot tree by the following symptoms:
- dried up branches and twigs
- Dried up bark
- Spots stand out on the bark
- Spots are black and slightly raised
- The spots then turn white
- secrete mucus in red color
- Fruits develop putrid spots
- Putrefaction of pustules outlined in red color
The toad skin bark is the typical sign of the disease.
