Help the development of the site, sharing the article with friends!
The heat-loving apricot tree originally comes from Armenia and China. Today it is widespread in our regions and sometimes also known as the apricot tree. Not only is it popular for its sweet fruit, it is also relatively easy to care for. Because apricot trees do not make great demands on the soil. But they love a warm, rain and wind-protected location. However, regular watering should only be done during dry periods. In early summer, when the weather is dry and the temperatures are high, the leaves on the apricot trees can sometimes hang limp, begin to wither and ultimately fall off. In this case it is necessary to get to the bottom of the causes.
causes
Don't wilt leaves from lack of water
At first sight, the assumption can quickly arise from such a sight that a lack of water causes the leaves to wither and dry up, since this phenomenon usually occurs in dry periods. But even watering cannot help the tree here. The plant continues to dry out slowly. The cause of this can be a sign of various diseases, such as:
- Verticillium wilt
- apoplexy
- Monilia laxa
Verticillium wilt
This disease is caused by the harmful fungi Verticillium dahilae (dark microsclerotia) and Verticillium albo-atrum (permanent mycelium). Their fungal spores can survive in the soil for more than ten years without a host plant. You get there via the root, for example after root pruning, into the plants, where they form toxins and ultimately block the water channels of the tree. Signs are:
- Leaves wither until they fall off
- Reduction of leaf growth
- Cracking of branches and shoots
- Balding and dying of individual shoots, later also of entire branches
- The whole tree dies off after a few years
- Occurs mostly on one side at first
- Additional occurrence of leaf yellowing and necrosis possible
- Slow course of the disease
- Periods of drought and high temperatures accelerate the course
- Fruits are small, sometimes inedible
- Definite proof only through laboratory analysis of the soil
tip: Due to scratching of the bark near the ground or on affected shoots, the longitudinal water channels underneath are discolored brownish.
Verticillium in branch cut
measures
Use of fungicides against Verticillium wilt is not possible
So far, it has not been possible to directly combat the harmful fungi using chemical agents. When the first symptoms become visible, you should act as follows:
- Carefully rake up fallen leaves and dispose of with household waste
- Remove dead branches and twigs directly at the base
- Don't leave stubs
- close cuts
- Prune diseased shoots far back into the healthy wood, at least 50 cm
- Using clean and sharp cutting tools
- Carrying out pruning measures in dry, sunny weather
- Completely remove dead trees
- Replace soil if necessary
tip: Ring-shaped dark discolorations in the area of the conductive pathways indicate Verticillium wilt on a cross-cut branch.
apoplexy
Apoplexy in apricots is also called slap meeting known. Apricot trees can die off in a very short time. The cause can be cold damage due to winter or late frosts. These lead to damage to the pathways under the bark. This is particularly critical for apricots, as they are the first to end their hibernation, and late frosts then usually occur. However, a heavy crop of fruit in the previous year, bacterial blight, shotgun disease or Monilia laxa can also promote the occurrence of the "slap hit". First signs of apoplexy:
- After initial sprouting, leaves and sprouts wither
- Encroachment on individual twigs, branches or the entire crown
- Typical gum flow below withered sections (blockage of pathways)
- Torn bark on strong branches and in the trunk area
- Highest mortality rate between the 3rd and 7th year of life
measures
Strengthen tree health and frost resistance
At the first sign of apoplexy, immediate action should be taken.
- Remove dead branches at the end of May
- However, stress due to high fruit load or strong growth with a lack of yield
- Balanced fruit thinning, at least one fruit per palm
- When planting new apricots, make sure they have frost-hard substrate
Monilia laxa
Monilia laxa is also called peak drought known. Infection with the fungus Monilia laxa occurs from bud formation until after flowering. The mycelium spreads rapidly and penetrates the fruit wood. The peak drought is also favored by rainy weather. However, the fungal spores can also overwinter on the dried leaves, twigs and fruit mummies on the tree. Since they have a high germination capacity, they multiply quickly in the spring after flowering. It is then spread by rain, wind and insects. You should look out for the following symptoms:
- Blackening of the inflorescence
- Pale green leaves on one year old wood
- 3 to 4 weeks after flowering, shoot tips, flowers and leaves wither
- Encroachment on entire branches, leading to peak drought
- Gum flow at the border between diseased and healthy tissue
measures
Cut back if infested
In order to avoid further damage, an infestation with Monilia laxa must be acted upon as quickly as possible.
- Chemical treatment is no longer possible in the event of an infestation
- Cut out all affected branches, infected flowers and fruit mummies
- Cut back dying branches down to 30 cm into healthy wood
- Preventive fungicide spray (fungus-free Ectivo or Duaxo Universal fungus-free)
- In addition, spraying at full bloom
Monilia laxa on an apple tree
General prophylactic measures
In order to avoid an outbreak of the disease from the outset, you should pay attention to a few things. Because here it is advisable to combine various preventive measures. Nothing stands in the way of a lush harvest of the delicious sweet fruits for years to come.
- Choose the best location, light, well-drained soil in a sheltered location
- Avoid soil with waterlogging, improve if necessary
- Don't plant too deep and don't damage the roots
- Use tree snorkels when planting
- If necessary, lowering the pH value of the soil by adding grape pomace, compost from coniferous wood or peat
- If necessary, replace the entire soil
- Soil improvement through the incorporation of active plant substances (e.g. radish or mustard plants)
- Balanced water and nutrient supply
- Avoid drought stress by watering regularly
- Fertilize with compost, patent potash or horn meal and shavings
- Avoid nitrogen-rich fertilization
- Regular thinning and pruning
- Close open cuts immediately
- Do not leave any branch stumps or fruit mummies
- Correct selection of varieties, such as Goldrich, Sylvevcot, Bergarouge, Harlayne
tip: Tree snorkels are jute bags filled with expanded clay for good root aeration. It is advisable to hire a specialist company in order to avoid root damage when installing it later.
Plant strengthening by natural means
Only healthy and strong trees have a good resistance to diseases. However, biological tonics can also be administered to keep the plant cells healthy and strengthen them at the same time. Manure made from horsetail, nettle, tansy, comfrey or wormwood have proven effective. These can be made quickly and without much effort, such as manure made from field horsetail:
- Pour 5l of water over 500g of fresh field horsetail
- Let the brew steep for 3 hours, heat up and simmer for 30 minutes
- Strain after cooling
- Use every 2 weeks for at least 4-6 weeks
tip: Preparations made from algae extracts and essential oils to strengthen resistance are also available in specialist shops. But there are also inorganic strengthening agents such as silicates, carbonates and phosphorus and potassium salts.