Common hazel, like most other plants grown in gardens, can be attacked by diseases and pests.The most common hazel diseasesare moniliosis, powdery mildew and leaf blotch. The first one damages the fruit, the other two - the leaves. We advisehow to recognize hazel diseasesand what are the best methodsprotection of hazel against diseases
Hazel leaves and ripening nuts should be monitored for the presence of diseases and pests
The most dangerous disease affecting hazel ishazel moniliosis , contributing to large losses in hazelnut yields.The disease is caused by the infestation of hazel by the fungus Monilinia coryli. The fungus Monilinia fructigena (known to fruit growers as the cause of brown rot of pome trees) or Monilinia laxa (the cause of brown rot of stone trees) also affects hazel less frequently. Hazel moniliosis manifests itself mainly by lesions visible on hazelnuts, i.e. hazelnuts. As a result of infection with this disease, dark brown, recessed spots appear on the green nuts, gradually spreading over the entire surface of the nut. Over time, infested nuts turn brown and mummify, with cream-colored clusters of fungal spores appearing on their surface. Monilia coryli fungus can also infect fruit buds and inflorescences, but it does not cause disease symptoms. This often causes the initial stage of infestation to be overlooked.
To reduce the occurrence of moniliosis, avoid over-compaction of the bushes by cutting the hazel regularly and removing the affected nuts.It is also worth choosing varieties that are not very susceptible to this disease, such as the common hazel 'Catalan' or 'Halle giant'.Spraying against moniliosisis performed from mid-May, repeating them 3-4 times at intervals of 10-14 days, alternating fungicides: Dithane NeoTec 75 WG, Sadoplon 75 WG, Topsin M 500 SC . In amateur crops, in order to limit the use of chemical plant protection agents, the mentioned fungicides can be used alternately with one of the biopreparations with a fungicidal effect available on the market.
Another disease that infects hazel ispowdery mildew of hazel , which is the result of infection of the bushes by the fungus Phyllactinia corylea. The powdery mildew infection is most often visible at the end of summer on the lower leaves of the shrubs. On the underside of the leaf blades, spots of a white, powdery coating appear. Leaves wilt and fall prematurely. In the fall, black surroundings with bags and sac-like spores of the fungus appear (in this form the pathogen hibernates).
In order to limit the spread of powdery mildew, the leaves that have fallen from the bushes should be systematically ruffled and removed (preferably burned). It is also necessary to avoid wetting the leaves when watering, and especially not to leave the leaves wet overnight (it is better to water in the morning). After noticing symptoms of the disease, apply several sprays at intervals of 7-10 days with the following preparations: Discus 500 WG, Domark 100 EC, Nimrod 250 EC, Score 250 EC.
Phyllosticta coryli can causehazel leaf spotAs a result of this disease, the first spots to appear on the leaves are round or oval, brown in color, sometimes surrounded by a yellow border. Over time, the spots on the hazel leaves increase in size and may merge with each other. Black spots of fungus sporulation are visible on the upper side of the leaf where the spots are formed.
As in the case of fighting powdery mildew on hazel, rake and remove the infected leaves, while watering, pour the water directly on the ground so as not to sprinkle the leaves, and avoid excessive thickening of the bushes.In order to protect hazel against leaf blotch, 2-3 sprayings are performed every 10 days with the use of fungicides: Discus 500 WG, Dithane NeoTec 75 WG, Topsin M 500 SC. They can be used alternately with the selected fungicidal biopreparation.
