Species: Trees and shrubs of the rose family like apples (Malus spp.), pears (Pyrus spp.), hawthorns (Crataegus spp.), photinia (Photinia spp.), roses (Rosa spp.), almonds, cherries, plums (Prunus spp.)
Symptoms: Young leaves, stems and flowers become brown or black, and new shoots look as if they as if scorched by fire (therefore the name for the disease). On the bark of the trunk, branches and twigs, sunken cankers may appear. It mainly attacks certain parts of the plant, but in severe cases it can attack the trunk and root and kill the plant.
Causes: The bacterium Erwinia amylovora causes this disease, it has been a quarantine disease in Europe since 1957. It is spread with contaminated tools (so it is always recommended to disinfect the tool with 70% alcohol after each use) and by insects that pollinate the flower. The bacterium rests over winter in cancer wounds on the infected part of the plant and reappears in the spring when the weather is warm and humid.
Consequences for the plant: Withering and dying of leaves, flowers, shoots and branches.
Treatment: As the disease is destructive in nature, prevention is recommended rather than treatment. In order to prevent the development of the disease, it is best to avoid strong pruning, fertilizers with higher amounts of nitrogen, and during the movement of vegetation until flowering, treat the plants with a copper preparation registered to control this disease Be sure to disinfect scissors after pruning each plant.
If the disease has already occurred, it is recommended to prune the infected parts 30 to 50 cm below the infection over summer or winter. Ensure tools are disinfected after each cut, and burn the infected parts of the plant. Finally, coat the cut with a 3% solution of copper preparation.
コメント