Help the development of the site, sharing the article with friends!
An apple tree is an integral part of the living inventory of local gardens. But those who find out about possible diseases and pests in advance will want to give up right away. Too many germs and small animals seek for its lifeblood. And yet there are millions of them: the abundantly bearing apple tree, with the most delicious fruits. Perhaps because many of the dangers are not as serious as feared. Or because the tree, united with its owner, is not at their mercy.
Apple Tree Diseases
Diseases of bark and wood
If the bark and wood of the apple tree suffer from the diseases described below, the supply to the other parts of the tree also suffers. If the tree is diseased, the quantity and quality of the harvest ultimately leave a lot to be desired. Those who have not been able to prevent these diseases through preventive measures can at most wrest a little more time from them.
collar rot
The fungal pathogen responsible for collar rot occurs naturally in soil. An infection is caused by this excessive moisture favored. Rainy periods but also heavy soil can lead to unfavorable waterlogging. However, the apple tree only shows the external symptoms from the fifth year of life.
- the bark is damaged
- small, rotten spots become visible
- expand more and more over time
- the bark sinks in and turns purple
- the underlying wood remains intact
combat
If the apple tree is sick, then any action comes too late. Only that helps Prevent:
- Avoid waterlogging and damage to the bark
- Plant less susceptible varieties
fruit tree cancer
Fruit tree cancer is one of the diseases caused by fungal pathogens caused. During the long course of the disease, various symptoms of the disease appear externally:
- cracked and dry bark
- with orange-brown discoloration
- sometimes individual branches die off
- Affected parts show round, orange spore beds
- strong growths sometimes form on the bark
combat
Even if the apple tree is sick, it can live on for years and even bear tasty fruit. The disease cannot be completely reversed, but it can be alleviated to some extent with a few measures. The strong growths protruding from the trunk are cut away and the open wounds are sealed with tree wax. You should also remove dead branches.
Fruit tree canker on an apple tree
root crop
Root goiter occurs even in young apple trees. The causative bacterium penetrates from the ground through open wounds into the roots and makes the tree sick. Sap flow is reduced, resulting in stunted growth and low crop yield. When buying new trees, pay particular attention to the following negative feature:
- swellings at the roots
- sometimes the size of an apple fruit
combat
There are no suitable measures that lead to the recovery of the apple tree. In the case of a severe infestation, it can even die quickly. Prevent by avoiding open sores from root damage. For example when digging. The pathogen can survive in the soil for several years without being damaged. Do not plant a new sapling here for the time being.
Root crop on pecan nut
diseases on leaves
The leaves, which supply energy to the apple fruit, sprout in early spring. Most illnesses affecting them can be easily combated with suitable measures, provided that the signs of illness are recognized early and interpreted correctly. Then the harvest can still be satisfactory.
apple powdery mildew
This fungal disease is insidious, not only for the one infested tree specimen. Thanks to the easy spread by insects, but also by wind and rain, the pathogen can spread to all parts of the tree in no time at all, as well as to neighboring trees. Then there is a risk of crop losses or total failure. The following visible signs of disease can be read from the green of the apple tree:
- white, powder-like coating
- preferably on young leaves and shoots
- curled leaves follow, which finally dry up
combat
A radical cut of the affected areas is unavoidable, cutting right into the healthy wood. If necessary, repeat the cut promptly. For stubborn infestations, sulfur preparations and fungicides can be used. As a preventive measure, keep the crown of the apple tree airy with suitable pruning measures.
tip: Watch out for wilted buds, they are harbingers of this fungal disease.
apple mosaic virus
Fortunately, this disease caused by a virus is triggered, a rare occurrence. A transmission of the disease by animal garden dwellers is not known, so other trees have nothing to fear. Only noble tears may not be taken from these trees. These are the signs of this viral disease:
- Leaves have white to yellowish spots
- Speckles form tessellated patterns
- Disease only shows up on a few shoots
- conquers the whole tree over time
combat
There is no cure for this disease. Combat is therefore not possible.
apple scab
Malus domestica, as the botanical name for apple tree is, is often the declared goal of scabs, although some apple varieties are more susceptible and fall ill early in the growing season. A rainy garden year accompanied by heat is ideal for this fungal pathogen, which is why you should pay attention to the symptoms of the disease:
- brown discoloration on the leaves
- uneven leaf structure, such as bumps
- dry leaves falling off in moderation
- later the effects are also reflected in fruits
- they are cracked in places and discolored brown
combat
From the outset, more resistant varieties should be used or your own apple tree should be strengthened in its resilience. Spraying with horsetail broth and regular thinning of the crown have proven effective. Affected areas must be cut down to healthy wood and infected leaves must be collected and disposed of. If these measures do not help, a fungicide can also help in the case of a heavy infestation.
tip: The fruits remain edible, the unsightly areas can be cut away. The cracked areas make it easy for rotting fungi to penetrate, which is why long storage no longer works.
fire blight
As the firebrand rages, no amount of "putting it out" can stop it. This bacterial infection is one of the most serious diseases that Malus domestica can afflict.
- young shoots are affected
- as well as flowers
- turn completely brown to black
- but stay on the tree
- the tree looks burnt
combat
The spread of fire blight is easily possible or probable due to the large insect population but also by humans. Fire blight usually leads to the death of the apple tree. Because of these two circumstances, fire blight is notifiable in this country. Notify the appropriate agency as soon as you spot any of the above signs on a tree. Control is not possible, but in the early stages the tree can still be saved by very large pruning measures, otherwise it should be cleared and completely burned.
tip: For new plantings, ask about resistant apple varieties.
Monilia - peak drought
If the monilia fungus spreads on leaves and flowers, this is referred to as the so-called peak drought. This disease shows clearly:
- puny, withered leaves
- at the shoot tips
combat
Immediately cut back affected branches to at least 30 cm into the healthy wood. Regular thinning reduces the risk of infestation. As a preventive measure, biological plant strengtheners are sprayed every two weeks from the moment the plants sprout.
Monilia peak drought on apple tree
Diseases that damage fruit
Apples that are already clearly marked by disease cannot be turned back into healthy specimens. Then it's just a matter of distinguishing between what is still edible and what absolutely needs to be disposed of. In a further step, the causes must be found and combated as best as possible so that the harvest in the following year does not suffer the same fate.
glassiness
At this metabolic disease the causes have not yet been fully clarified. However, calcium deficiency, too much solar radiation and an imbalance between the foliage and the amount of fruit are suspected to be beneficial factors. The sliced apple doesn't look appetizing. However, consumption is not harmful to health. Only the taste can suffer. In this case, however, the apple can still be processed into mush or something similar.
- Apple produces too much sugar
- Flesh is glassy and watery
- mostly around the case
- freshly harvested apples affected
- Glassiness partially decreases after storage
combat
Avoiding glassy apples begins at planting with choosing a less susceptible variety and a slightly shadier location. Cut back greenery that is proliferating on the apple tree, leaving enough foliage as sun protection. Also pay attention to a fertilizer containing calcium.
calyx rot
If the apple fruits show damage in the calyx area, calyx rot is up to mischief. It is also often referred to as core rot. Most of the time, damp weather has created favorable conditions for her. the infection with the pathogen has already taken place during flowering and shows up visibly in the harvest season.
- dark brown spots in the calyx area
- dry and sunken
- inside, the core is brown and putrid
- during storage, the pulp can also rot
- affected fruits ripen earlier
- fall prematurely from the tree
combat
Infested fruits are promptly and completely collected and disposed of. You should only take appropriate measures if collar rot keeps appearing on your apple tree over the years. Spray preventively in wet weather during the flowering period.
Monilia - fruit rot
Humid weather combined with a dense canopy greatly ruins the apple crop. the mushroom then spreads extremely quickly, with small punctures from codling moths and apple sawflies providing ideal access.
- healthy fruits turn into fruit mummies
- turn brown with spots of white mold
combat
Collect and dispose of all infested fruits promptly so that the fungal pathogen cannot spread further. However, the brown fruits must not end up on the compost heap. But also fight the above pests, which significantly contribute to an unfavorable course of the disease.
sooty spot disease
In private gardens, where preventive spraying with fungicides is not the order of the day, sooty spot is one of the most common fungal diseases on apple trees.
- patches of different sizes on fruit
- greenish-black colour
- cannot be completely removed by rubbing
- heavy infestation covers the whole fruit with a black coating
combat
Since the fungus is also spread by moisture or raindrops, an airy crown must ensure quick drying. Therefore, dense branches must be thinned out. Spraying against apple scab is also effective against the pathogen that causes sooty spot disease.
dullness
Also these metabolic disease probably causes a calcium deficiency. At the same time, increased levels of magnesium and potassium are found. A lack of calcium in the soil does not necessarily have to prevail, rather its transport in the tree is decisive. This is not optimal for some varieties. The symptoms only appear on the fruit and must be accepted for the current harvest.
- Flesh has brown spots
- often only appear during storage
- the apple flavor is initially still edible
- but becomes more and more bitter as time goes by
- Jonagold and Boskop are particularly vulnerable
- the apple variety Golden Delicious less
combat
Trees that are not very productive should experience a reduction in foliage by pruning in the summer. From July, the fruits can be treated several times with 0.5% calcium chloride sprays.
tip: About two weeks before harvest, pick some apples and store them in plastic at around 30°C. If the symptoms of the disease then appear, you should refrain from storing them for a longer period of time.