Taphrina deformans is the causative agent of peach and almond leaf curl disease. The fungus spends the winter period on twigs, under affected buds, and in the cracks of bark. The climatic factors suitable for the spread of this disease are a relatively warm and humid winter in addition to humid spring with an average temperature of 13-18 degrees Celsius. A particular stage where trees are suceptible to the fungus is the formation of Leaves inside vegetative buds up until the end of leaf growth.
Symptoms of infection
The first signs of the disease appear at the beginning of the appearance of the leaves, and they are:
- Deformation and wrinkling of newly grown leaves
- Leaves turn reddish-yellow in early spring
- Increased thickness of wrinkled leaves
- Strong fall leaves in summer
- A white waxy flower forms from the spores on the underside of infected leaves
In the future, these leaves and buds will die, which greatly weakens the trees and leads to their wilting.
Prevention and control
Agricultural operations alone are not useful in avoiding injury, and therefore it is recommended to:
- Choose resistant varieties
- Cut and burn infected parcels
- Trim trees
The timing of spraying with chemical compounds is very important, but the control after the injury does not work much. Therefore, it is recommended to preventatively spray the affected trees in the previous season at the end of autumn and the beginning of spring with copper or chemical compounds chlorothalonil or ziram.
Chemical pesticides based on ziram were the basis and most used to combat peach wrinkle disease, but after the import of this substance was prevented due to suspension or prevention of its use in some countries of the world, an effective chemical alternative was resorted to in combating this pest, which is the pesticide “Syllit”. Which also has high effectiveness on other fungal diseases such as spotting and apple scab or peacock’s eye on olives, etc.
Syllit belongs to the unique family of the U12 GUANADINE group. It is a suspension concentrate of DODINE, which is currently considered one of the rare pesticides in the fight against leaf curl disease.
Syllit is characterized by local preventive and curative effects, and a guaranteed therapeutic efficacy even after 48 hours of injury or rain. It is also not harmful to beneficial insects.
It can be sprayed even on wet leaves and at low temperatures and has a side effect on bacterial diseases
One of the advantages of using Syllit is to reduce the use of copper compounds on the foliar mass, which subsequently reduces chemical deposits and copper residues in the environment.
Syllit is used at a rate of 100-150 mm/100 liters of water to combat the wrinkling of almond leaves and peacock’s eye on olives, while it is used at a lower rate of 80-100 mm/100 liters of water to combat the apple scab Venturia inaequalis or Fusicladium eriobotryae.
by Eng. Mostafa Saadeh