Peach leaf curl is a fungal disease caused by Taphrina deformans that affects peach tree leaves. The fungus survives winter on buds and twigs and infects leaves in spring when temperatures are below 16°C and rainfall wets leaves for over 12.5 hours. Diseased leaves become thick, rubbery, and distorted and change color from green to red and purple. Common control methods include fungicide sprays and planting resistant cultivars.

1. PEACH LEAF CURL
SUBMITTED BY COURSE TEACHER
J.MAHESHKUMAR Dr. S. PARTHASARATHY
2015021073 Asst. Prof. (PLANT PATHOLOGY)

2. Peach Leaf Curl
• Causal organism: Taphrina deformans
• Distribution:
America,
Europe,
Asia,
Australia,
New zealand

3. Systemic Position
• Kingdom : Fungi
• Phylum : Ascomycota
• Class : Taphrinomycetes
• Order : Taphrinales
• Family : Taphrinaceae
• Genus : Taphrina
• Species : T. deformans

4. Symptoms
 Diseased leaves can usually be identified soon after they
emerge from the bud, due to their red color and twisted shape.
 As the leaves develop, they become increasingly distorted,
and ultimately thick and rubbery compared to normal leaves.
The colors of the leaves change from the normal green to red
and purple.
 Fruit may fail to develop from diseased blossoms, or may be
affected, showing a reddish colour.

6. Pathogen description
• Intercellular mycelium devoid of ascocarp.
• Naked asci are produced individually and bear eight
ascospores.
• Ascospores undergo budding division before released
from ascus.

7. Disease cycle
• Peach leaf curl is caused by the fungus Taphrina
deformans. This pathogen is called monocyclic,
meaning these fungal spores infect peach leaves only
once a year in the spring.
• Taphrina deformans survive winter on buds or twigs of
the tree.

9. Favourable condition
• For successful infection, the fungus requires cool
and wet winters, where rain wets the tree for
more than 12.5 hours at temperatures below 16°C
(61 °F).

10. Management
• The most effective method is to plant peach trees possibly
covered by a mat during the winter, to keep winter rain
away from the buds before they burst (incidentally to
delay blossoming until spring frosts are over)
• Spraying the leaves with fungicides is the most common
control method.

11. Copper based mixtures (such as bordeaux mixture) and lime
sulphur are two fungicides commonly used.
• Peach cultivars can be planted which show some resistance
to peach leaf curl, or at least regenerate rapidly, such as
Peach 'Benedicte'.
• No similarly resistant nectarine cultivar is yet known.

12. References:
"Peach--Leaf Curl." An Online Guide to Plant Disease
Control. 01 Jan 2008. Oregon State University. 14 Apr 2009
<http://plant-disease.ippc.orst.edu/disease.