16 Plum Tree Diseases: Curled Leaves & Co

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16 Plum Tree Diseases: Curled Leaves & Co - Cover picture

table of contents

  • Plum tree diseases
  • from A to N
  • from M to R
  • from S to U
  • from V to Z
  • frequently asked Questions

If the leaves, fruits or shoots on the plum tree (Prunus domestica) suddenly change, quick help is required. We have put together the most important tips for combating plum tree diseases and pests for you.

In a nutshell

  • Changes to leaves, shoots or fruits due to pests, diseases or care errors
  • Monilia fruit rot and Sharka disease dangerous
  • regular check-ups to prevent diseases or to treat them in good time
  • Professional pruning strengthens vitality and prevents diseases
  • Natural gardening promotes the settlement of beneficial insects and prevents pest infestation

Plum tree diseases

Diseases of the plum tree can have various causes.

  • Pests
  • Viruses
  • bacteria
  • mushrooms
  • Location and maintenance errors

from A to N

Bacterial burn

Plum tree disease: bacterial blight

Symptoms:

  • grooved, black-red injuries on trunk and branches
  • in April / May these tear open and rubber flow occurs
  • stunted buds
  • Leaf changes in May with shotgun-like, translucent holes with a yellow border
  • The trees die in the event of severe infections

Root cause:

  • Bacteria Pseudomonas syringae

Prevention or control:

  • thorough removal of dead and diseased shoots
  • Cut after harvest, not in winter
  • Whiten the trunk against frost cracks and infections
  • Avoid cold locations

Galena infestation

purple bark layer fungus Stereum purpureum Pers.
The cause of the galena can be the violet cartilage fungus (Chondrostereum purpureum) or a physiological disorder. Source: Jerzy Opioła, Chondrostereum purpureum G3.1n, edited by Plantopedia, CC BY-SA 3.0

Symptoms:

  • green-silvery sheen on leaves and twigs
  • Restriction of plant growth
  • Reduction of the yield
  • Individual parts of the tree die off

Root cause:

  • Harmful fungus Chondrostereum purpureum

Prevention or control:

  • Plant strengthening with horsetail broth
  • thorough removal of the fallen leaves and the diseased plant parts

Double fruits

Plum tree disease: double fruits

Symptoms:

  • Twin fruits on a fruit stalk

Root cause:

  • high temperatures in the period of flower development

Prevention or control:

  • not known

Note: The taste of the plums is not affected by this plum tree disease.

Throat wilt

Plum tree disease: throat wilt

Symptoms:

  • Plums become soft and shrink in the upper part
  • Decrease in taste
  • Crack formation in the stem area
  • Fruits taste bland
  • The pulp becomes crumbly

Root cause:

  • frequent occurrence when alternating longer dry and wet phases in summer

Note: Plum tree throat wilt disease occurs mainly in late varieties. Ortenauer, Hanita, Hauszwetsche and Elena are particularly susceptible.

Prevention or control:

  • choose resistant varieties

Caverns and broken stones

Caverns and broken stones are usually significant exclusion criteria for the sale of the respective plum in brick-and-mortar stores.

Symptoms:

  • reddish cracks in the pulp
  • Stones split or tips break off
  • gelled juice inclusions

Root cause:

  • inharmonious growth spurts

Prevention or control:

  • choose modern, resistant varieties when replanting

from M to R

Monilia fruit rot

Plum tree disease: Monilia fruit rot

Symptoms:

  • sudden rotting of the fruit in July and August
  • brown or yellow-brown, growing spore beds on fruits

Root cause:

  • Harmful fungi Monilia laxa or Monilia fructigena

Prevention or control:

  • consequent removal of fruit mummies on the tree and on the ground
  • Removing diseased branches
  • Cut back into the healthy wood
  • Thinning out the treetop

Note: Do not dispose of diseased plant parts on the compost, but in the residual waste or in the organic waste bin to prevent them from spreading.

Fool's or pocket sickness

Fool's or pocket sickness
Source: Star renette, Fool's disease of the plum (house plum), edited by Plantopedia, CC BY-SA 4.0

Symptoms:

  • young fruits deform and shrink
  • turn greenish in color
  • furry coating on the plums
  • premature fall of the fruits

Note: Species that are particularly endangered by plum tree disease are: 'Ortenauer', 'Bluefree', 'President' and 'Hauszwetsche'.

Root cause:

  • Harmful fungus Taphrina pruni
  • humidity

Prevention or control:

  • Remove diseased twigs and fruit mummies immediately
  • Rejuvenation pruning in older trees
  • Splash horsetail or tansy broth
  • Plant the garlic on the tree slice

Note: The 'Tophit' variety is considered to be resistant to the fool's disease.

Fruit tree spider mite

Fruit tree spider mite
Source: \ ldblquote, Red spider, edited by Plantopedia, CC0 1.0

Symptoms:

  • sudden leaf changes in June and July
  • Leaves turn silver or bronze in color

Root cause:

  • Fruit tree spider mite Panonychus ulmi

Prevention or control:

  • Thoroughly remove diseased parts of the plant
  • Establish beneficial organisms

Plum louse

Plum louse
Source: Sarang, Plum leaf with floury plum aphid 2, edited by Plantopedia, CC0 1.0

Symptoms:

  • Leaves curling
  • pale green lice

Root cause:

  • Plum louse, Brachycaudus helichrysi

Prevention or control:

  • Removal of affected parts of the plant
  • Spray with horsetail or garlic stock
  • Remove root shoots in autumn

Plum moth larva

Plum moth larva
Source: Slimguy, 2017 08 08 Grapholita funebrana, edited by Plantopedia, CC BY 4.0

Symptoms:

  • Falling off the Stone fruit-Fruit

Root cause:

  • Plum moth Cydia funebrana

Prevention or control:

  • Shake the plum tree frequently
  • Dispose of fallen fruit
  • Remove affected parts of the plant
  • Spray with neem oil solution
  • Attach fruit maggot trap made of corrugated cardboard

Bursting of fruits

cracked and popped plum

Symptoms:

  • Fruits tear open
  • Putrefaction arises

Root cause:

  • strong rainfalls

Prevention or control:

  • choose resistant varieties

from S to U

Sharka or smallpox disease

Sharka or smallpox disease
Sharka or smallpox is illustrated by another plant. This plum tree disease looks similar on affected trees. Source: User: MarkusHagenlocher, Sharka leaf symptoms, edited by Plantopedia, CC BY-SA 3.0

Symptoms:

  • light and olive green spots on the leaves in early summer
  • later black dots
  • premature fall of the fruits
  • pox-like depressions in the skin of the fruit
  • gummy consistency of the pulp

Root cause:

  • Sharkavirus
  • is transmitted by aphids or by grafting
  • more common with long periods of drought

Prevention or control:

  • complete control not possible
  • infected trees must be cleared
  • Preventing the spread by fighting the transmitting insects
  • Use of virus-free documents for grafting
  • Prefer less susceptible varieties

Note: Sharka disease is that most dangerous viral disease with plums, plums and apricots. Signs of this disease are according to the Ordinance to Combat Sharka Disease notifiable! Sharp cat-tolerant varieties can become infected, but their fruits remain edible.

Shotgun Sickness

Shotgun Sickness
Symptoms of shotgun disease on a cherry leaf. The clinical picture looks similar in a plum tree. Source: cool grill, Shotgun Cherry Leaf, edited by Plantopedia, CC0 1.0

Symptoms:

  • red-brown spots on young, infected leaves
  • Spots fall out of the leaf tissue
  • Perforation of the leaves

Root cause:

  • Harmful fungus Clasterosporium carpophilum
  • damp weather in spring

Prevention or control:

  • Thoroughly remove fruit mummies
  • Dispose of diseased leaves and parts of plants immediately
  • Thinning out the treetop
  • Plant garlic on tree slice

from V to Z

Valsa toad skin disease

Valsa toad skin disease
This branch affected by Valsa toad skin disease is not a plum tree branch, but is well suited for visualization. Source: This image was created by user Gerhard Koller (Gerhard) at Mushroom Observer, a source for mycological images. You can contact this user here. English | español | français | italiano | македонски | മലയാളം | português | +/−, 2012-05-26 Valsa ambiens (pers.) Fr 223504, edited by Plantopedia, CC BY-SA 3.0

Symptoms:

  • wart-like, black spots on the branches, which later turn white and secrete reddish mucus
  • Rubber flow on the trunk and on the branches
  • Rotten spots on the fruits
  • Twigs dry up

Root cause:

  • Leucostoma fungus that penetrates the wounds

Prevention or control:

  • Thoroughly remove infected parts of the plant
  • Disinfect the tool carefully
  • Strengthening with horsetail broth

Browning of the pulp

Plum tree in the blazing sun
Presumably, overheating at temperatures above 30 ° C leads to a breakdown of the pulp.

Symptoms:

  • Just before ripening, plums suddenly become soft and glassy - ripening no longer progresses
  • Fruits taste like they are cooked

Root cause:

  • longer periods of heat with temperatures above 30 degrees Celsius

Prevention or control:

  • choose a shady location when replanting a plum tree

Note: The browning of the pulp often occurs together with sunburn.

Plum grate

Plum tree disease: plum rust

Symptoms:

  • rust-colored spots and pustules on the underside of the leaves
  • mosaic-like yellow patterns on the leaf tops
  • early shedding of leaves in the event of severe infestation

causes

  • Rust fungus

Prevention or control:

  • Destroy ornamental junipers in the vicinity
  • Strengthen trees with horsetail broth
  • Thoroughly dispose of fallen leaves
  • do not plant anemones or winterlings near plums

Note: The rust fungus occurs regularly in damp locations in sensitive varieties. He has no influence on the edibility of the fruit.

frequently asked Questions

Which location can strengthen plum trees and protect them from diseases?

Plum trees need deep soil with high water holding power. Waterlogging must be prevented by drainage. Plant the tree in a sheltered place near the house. Keep the tree grate free of weeds. Water when it is dry.

Which varieties are considered to be resistant to the Scharka virus?

The varieties 'Freiya' and 'Jojo' are currently the only resistant varieties. 'Opal', 'Elena', 'Kathinka' and 'Tophit' are considered sharka-tolerant.

Can diseased fruits or plant parts be composted?

Opinions differ on this question. Most of the pathogens are completely destroyed in compost heaps, which are heated inside to temperatures of up to 70 degrees Celsius. To be on the safe side, we recommend that you dispose of all parts infected by pests or diseases in the household waste or in the organic waste bin.