Peach leaf curl
Class: Fungi
Common Name
Peach leaf curl
Scientific name
Taphrina deformans
Potential Hosts
Peach, plum, nectarine, and almond
Who am I?
Peach leaf curl is caused by the fungus Taphrina deformans and is a common fungal disease that infects several plant species. Though, peaches are the most susceptible crop and hence the name.
The pathogen can be found on the host’s branches, buds, and bark. It can survive harsh weather conditions, withstanding summer's high temperatures and prolonged dryness.
At the end of a dormancy period, the fungus activity extends due to significant wetting events. As the weather changes and the flower buds swell, water splashes from irrigation or rain and causes fungus spores to reach the buds. That’s where the infection takes place, despite the fact that no green tissue is present.
After the pathogen enters the host, it stimulates cells, which leads to abnormal growth. Visual symptoms first appear as reddish areas on newly emerged leaves. With time, swelling and leaf distortion cause fungus spores to break outside, release into the air, and infect new tissues.
As the disease progresses, leaves may fall and be replaced by a new set of healthier leaves if a period of low humidity is present during their development. The loss of leaves during springtime results in decreased fruit production, defoliation, and could expose branches to sunburn.
Control measures
Control of peach leaf curl disease revolves around prevention through the use of chemical treatments. Broadly speaking, it is fairly common to perform two spraying treatments that are timed with respect to the physiological phase of growth. It is advised that the first treatment is implemented before buds swell, and the second treatment is implemented closer to the bud swelling process.
Conventional (chemical)
The following are generic names of fungicides used in one or more parts of the world: dithianon, captan, copper based fungicide, and bordo mix.
Caution and careful notice should be taken when using any plant protection products (insecticides, fungicides, and herbicides). It is the grower’s sole responsibility to keep track of the legal uses and permissions with respect to the laws in their country and destination markets. Always read the instructions written on labels, and in a case of contradiction, work in accordance to the product label. Keep in mind that information written on the label usually applies to local markets. Pest control products intended for organic farming are generally considered to be less effective in comparison to conventional products. When dealing with organic, biologic, and to some extent a small number of conventional chemical products, a complete eradication of a pest or disease will often require several iterations of a specific treatment or combination of treatments.