Ash(Fraxinus) is a viable tree quite resistant to diseases and pests. Although pathogens rarely attack this tree, there are quite a lot of diseases and pests that can threaten the ash tree. It is worth getting to know them and learn how to distinguish them in order to apply the appropriate methods of treating the tree. Here are the most commondiseases and pests of ashand ways to combat them. We recommend the best ash sprayers.
Common ash - Fraxinus excelsior
Fig. pixabay.com
Physiological diseases of ash
Browning leaves and dying ash shootsis a physiological disease. Excess water caused by abundant rainfall or too closely located water reservoir leads to rotting of the roots. As a result,the leaves of the ash turn yellow , turn brown, and the entire shoots die. In order to prevent these symptoms from occurring, ensure that the soil is well-drained and that the ash growing position is slightly inclined.
Fungus diseases of ash
Ash dieback is a very dangerous diseaseoccurring throughout Europe. Unfavorable habitat conditions and the activity of the fungus Hymenoscyphus fraxineus lead to infection, the symptoms of which are often: dieback of fragments and entire shoots, discoloration and distortion of leaves, and scars and necroses on the trunk. Common ash is most often attacked by this disease.
Ash dieback caused by the fungus Hymenoscyphus fraxineus
Fig. Food and Environment Research Agency - FERA, OGL v1.0, Wikimedia Commons
No method has been found yetcombating this dangerous ash diseaseIn small areas, thorough raking of the leaves, on which the fungus spores overwinter, is recommended. It is also recommended to remove heavily infected trees, the trunks of which show visible disease symptoms.
Dust of ash seedlingscaused by a number of pathogens (Phythium ultimum, Botrytis cinerea, Fusarium spp., Rhizoctonia solani, Phomopsis spp.) Causesbrowning and death of ash seedlingsThe same pathogens cause seedling gangrene in many other plant species as well. Older ash trees develop root rot and root rot, which causes the plant to die. Pathogens often live in the soil, on plant debris, and are transmitted by infected seeds.Infected seedlings should be removed and the still he althy ones should be watered with a fungicide, e.g. Magnicur Energy 840 SL or natural Polyversum WP.
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Phytophthora(Phytophthora spp) - attacks the roots of both seedlings and older ash specimens. Damaged seedlings turn yellow and can be easily removed from the ground. The pathogen, infecting older trees, causes growth inhibition, shoot dieback, browning, cracking and rotting of the base of the trunk.
The pathogen's spores overwinter in soil and plant debris. They also spread with water. Phytophthora is a disease that affects many different plant species at various stages of their development.
If we noticesymptoms of this ash disease , the infected plants should be removed and the remaining ones watered with a natural preparation of Polyversum WP or with chemicals e.g .: Scorpion 325 SC or Magnicur Energy 840 SL.
Werticilioza(Verticillium dahliae) infects both ash seedlings and older plants. It manifests itself in summer with yellowing of one side of the leaf blade. Then the ash leaves turn brown and fall off. Necrotic spots appear on shoots affected by the fungus. The spores live in the soil and penetrate the plant through the roots.Spray the infected ashwith natural agents such as: Biosept Active, Biochron AL or, in more severe cases, with the fungicide Scorpion 325 SC.
Ash leaf blotch(Discula fraxinae, Cercospora fraxinites) causes the appearance of round, mostly dark spots on the leaves that merge to cover the entire leaf blade. Dark fungus spores are visible on the underside of the leaf. Ash leaves die and fall off. The disease can also affect ash shoots with cancerous lesions. The spores travel with the air and overwinter in soil and plant debris.In order tofight this ash diseaseafter the season, carefully rake the fallen leaves and spray the infected plants with a natural preparation based on Biosept Active grapefruit extract or the fungicide Scorpion 325 SC.
Powdery mildew(Phyllacitinia guttata, Microsphaera alni) causes small spots on the leaves to appear on the leaves in the second half of summer, covered with a powdery mycelium coating. Over time, the spots grow larger and coalesce. The fungi also attack flower buds and fruit. Infected organs die and fall off. If in the previous season, powdery mildew was present on ash, then in May and June of the following year it is worth performing preventive spraying with natural preparations: Biosept Active, Evasiol, Lecitec or Limocide. If, nevertheless, symptoms of this disease appear on the ash, spray the trees with the fungicide Scorpion 325 SC.
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Vermillion nuggets(Nectria cinnabarina) most often occurs on older trees growing in high density. It manifests as cinnamon lumps on the bark of the trunk. The leaves of the affected trees become brighter, then turn brown and fall off. After noticing the symptoms, remove the affected shoots weakened by the fungus, and preventively spray the whole plant with Biosept Active.
Ash pests
The ash spike(Aceria fraxinovorus) is a mite that occurs mainly on older common ash specimens. It feeds on the inflorescences, distorting them into green (browning over time) cauliflower-like formations that remain on the branches until the next season. To combat this pest of ash, spray e.g. with Siltac EC in the period of bud bursting and leaf development.
Ash rust remover(Aculus epiphyllus) is a mite that feeds on the underside of leaves. Damaged leaves curl downwards and become finer. We fight like our predecessor with Siltac EC spray.
Apple crustacean(Lepidosaphes ulmi) - this is June from the family of scales. The larvae and female insects feed on the shoots, inhibiting them. Leaves on infected trees are smaller than in he althy specimens. If the trees are attacked by apple shells, spraying must be performed twice during the larvae lodging period. This date coincides with the flowering of the hawthorn, which may be a useful clue. To combat the pest, we can use natural preparations such as Agrocover, Emulpar 940 EC or stronger agents, such as Karate Gold or Siltac EC.
Cotton ash and fir(Prociphilus bumeliae) is a two-house aphid that feeds on the lower side of the leaves and on the tips of young shoots. Infected leaves curl strongly downwards and young shoots die. During feeding, the aphid secretes a honey honeydew. After noticing the feeding symptoms of this ash pest, we spray it with preparations based on natural ingredients such as Agrocover, Emulpar 940 EC or with chemical agents: Siltac EC, Karate Gold or Mospilan 20 SP.
The ash moth(Desineura fraxini) is a common ash flycatcher. On the lower side of the leaf, along the veins, it forms galls in which the larvae develop. Infected leaves turn brown and die. In order to border the population of this ash pest, we spray with oil preparations, e.g. Emulpar 940 EC or Agrocover.
Jesik budkowiec(Prays fraxinella) is a butterfly from the tentaceae family, the larvae of which dig tunnels in the apical buds. The juice leaking from the buds, which turns into a white substance on the surface, indicates that the pest is feeding. Young shoots growing up in spring turn black and wilt. Spraying against this pest is carried out at the end of July and in August with agents such as Mospilan 20 SP or NeemAzal T / S.
Ashwort brooch(Macrophya punctumalbum) is a hymen whose larvae gnaw round holes in the leaves.Adults scrape the top of the tissue, leaving behind the innervation and visible fecal dots. After noticing the pest, spray with Karate Gold.
Pilarz osinowiec(Tanthredo vespa) is a Hymenoptera whose larvae gnaw through holes in the leaf blade starting from its edge. The larvae feed in July and August. To combat this ash pest, we can spray the infected trees with Karate Gold.
MSc Eng. Anna Błaszczak
