The Monilia peak drought is caused by the fungal pathogen Monilia laxa, whose spores first infect the flowers and then penetrate the young shoots. Initially, this disease primarily affected stone fruit, in particular cherries, plums, apricots and peaches, but ornamental plants such as almond trees are increasingly becoming victims. Apples and pears are also among the host plants of the fungi. The stubbornness of the Monilia peak drought is mainly due to the fact that the fungus overwinters in the affected branches and fruit mummies in order to destroy young shoots and flowers again the next year. In early spring, even before flowering, large quantities of spores are formed, which are spread by wind, rain and insects and infect new trees. They even penetrate flowers that are still closed. According to previous experience, the fungus does not grow into older wood. Various methods have now been developed to successfully combat the Monilia peak drought, as described below.
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Prevention is better than cure
Since weakened trees are much more susceptible to the Monilia peak drought, the choice of location is a preventive measure to combat it. Waterlogging weakens the fruit trees from the roots and should be avoided anyway. Therefore, it is advisable to prevent the formation of waterlogging when planting the trees by choosing a sunny location and drainage made of gravel, granulate or shards of clay. Since the cold and wet also weaken the young shoots of the fruit trees, they are protected by a cover, e.g. B. from jute bags or foil.
As can be seen from the numerous field reports on combating this tree disease, the disease spreads more strongly in cold, wet weather in spring. For this reason, the hobby gardener takes a close look at indicator plants such as almond trees and forsythia early in the year. In addition, it is advisable to give preference to fruit trees that are less susceptible to the Monilia peak drought.
Hardy tart cherries
- Ludwig’s early
- Great Auburn Delicious
- Burlat: early ripe variety
- Summit: firm but prone to cracking
- Sylvia: Platzfest Sorte
- Regina: late maturing
Insensitive plum varieties
- Kernechter from the foothills
preference, because the Monilia peak drought also has little chance with them. In addition, experienced hobby gardeners advise treating endangered fruit trees with fungicides as a preventive measure, also to get rid of any fungal spores that may already be present. The federal plant protection product database regularly publishes a detailed list of all permitted sprays in hobby gardens for preventive fungal treatment. Further preventive measures for successfully combating the peak drought are:
- always remove all fruit mummies;
- thin out the tree regularly;
- strengthen with mineral-organic fertilizer;
- cut off the shoot at the first symptoms;
Since according to all previous experience, the two-year-old wood is not affected by the Monilia peak drought, it is sufficient to cut back affected shoots at the first sign, usually over a length of about 20 cm. The gum flow, which usually occurs at the transition from diseased to healthy wood, gives an indication of how far to cut back. In this way, there are good prospects that the fruit tree will be able to sprout healthy again in the coming year and develop flowers. Forward-thinking hobby gardeners carry out the preventive actions to combat the Monilia peak drought together with their like-minded neighboring gardeners across borders, because the dangerous spores do not stick to property boundaries.
Monilia fight peak drought biologically
In contrast to commercial fruit growing, no chemical agents against the disease are allowed in private gardens. In principle, these would hardly be successful in getting rid of the fungi. Once the shoots and blossoms are infected, the only thing left to do is radically cut back into the healthy wood. Under no circumstances should the cuttings be disposed of in the compost, but burned or buried. To keep peak drought away, experts recommend the following biological remedies:
pome and stone fruit trees
The copper lime solution often recommended up to now, also called Bordeaux mixture, is no longer allowed in Germany. An alternative is the use of pitcher clove extract, which is used in a variety of ways in organic farming, including to prevent peak drought conditions in Monilia. Since making your own is extremely complicated, it makes sense to buy it from a specialist shop and spray it before and after flowering. In addition, wasp traps help to ensure that the fruit is not injured by these insects and therefore becomes susceptible to the fungal disease. Should it be necessary to cut diseased shoots back into the healthy wood, the wound is immediately washed out with vinegar water and closed with clay mush. The new growth can be forced with nettle manure.
This remedy consists of a mixture of different stone flours, which also work against peak drought.
The finished product consists of horsetail, comfrey and wormwood. It can be purchased from specialist retailers or, alternatively, you can make it yourself. The effect is particularly effective in dry weather and in sunshine.
This biological remedy made from plant extracts strengthens the fruit trees so that they are vital and resistant to the Monilia peak drought.
Protect forsythia, almond trees and goldbells from peak drought
In addition to the pome and stone fruit trees mentioned, forsythia and goldbells are also susceptible to the Monilia peak drought. As so-called indicator plants, the fungal spores get to work on them early on because they bloom before the fruit trees, especially the cherry trees. Shortly after flowering, wilted leaves and flowers appear on the upper shoot tips. These dry up within a short time, fall off or hang lifeless on the plant. If you look closely, you will see an inconspicuous lawn of fungi on the affected areas. The risk of infection is particularly high in damp and cool weather. A loose plant structure, which is maintained by regular pruning, has proven to be a preventative measure. In order to save the plant in the event of an infestation, the diseased shoots are cut back into the healthy wood. Of course, fungicides can also be helpful for forsythia, almond trees and goldbells to relieve peak drought. However, the application only promises satisfactory success during the flowering period.
With the Monilia peak drought comes fruit rot
The fungus Monilia laxa not only causes the dreaded peak drought, but also nests in the fruit and causes it to rot. The related type of fungus Monilia fructigena has a similarly damaging effect and its effects can hardly be distinguished from Monilia laxa. No pome or stone fruit varieties are spared. Small, brown spots of rot appear on the fruits that fall victim to them. Especially if the fruit has small injuries, the fungal spores attack them. Within a short time, the rot spreads over the entire fruit. The disease can be recognized by the so-called upholstery mold. These are ring-shaped arrangements of the fungi on the fruit. These diseased fruits either fall from the tree or they remain on the tree as fruit mummies. In the case of stored fruit, such as apples, there is another characteristic of fruit rot. In this case, the whole apple turns black and the surface appears leathery.
Successful measures against Monilia fruit rot
First of all, all preventive measures that are also recommended for combating the Monilia peak drought apply with regard to site selection and tree care. In addition, the following countermeasures are recommended:
- pluck mummified fruits before flowering;
- pick these up from the ground as well;
- do not dispose of on the compost heap.
Ideally, these measures are also carried out on neighboring properties, because the fungal spores can be spread across all borders. Since no chemical sprays are currently available to combat fruit rot or are permitted for private gardens, experienced hobby gardeners report good success with the following biological preventatives:
- Chop approx. 300 g fresh leaves
- Boil briefly in 1 liter of water
- Leave for 24 hours
- strain through a sieve
- Dilute 1:10 with water
- Spray every 2 weeks from the beginning of flowering
Onion Skin Tea
- 75 g chopped onions
- boil in 10 liters of water
- sift through
- point undiluted on the trees
- 1 kg horsetail in 10 l water
- alternatively 300 g dried plants
- Cook for 30 minutes and let cool
- Sieve and dilute 1:5
- Splash alternately with horseradish tea
One of the most important preventative measures of all is avoiding any injury to the fruit. Because even the smallest crack in the skin gives the fungal spores unhindered access to the fruit. As ripening progresses, the fruit becomes more susceptible to infection. For this reason, a daily check of endangered trees is essential. If the first symptoms of fruit rot appear, the fruit should be removed. As a precaution, fruits that appear healthy are also picked that come into contact with the sick neighbors.
With vigilant hobby gardeners, the Monilia mushrooms have no chance of gaining the upper hand in the garden. Anyone who knows the growth and spread conditions for this fungal disease can take timely measures to get rid of the spores and prevent the disease from breaking out in the first place. Anyone who basically makes sure that their fruit trees are vital and healthy has often won the battle beforehand.