Diseases of Fruit Plantation Medicinal and Aromatic Crops

Peach leaf curl disease

Causal organism: Taphrina deformans
In India this disease is prevalent in Himachal Pradesh, Jammu & Kashmir and
Symptoms

• The disease first appears in the early spring as the leaves begin to unfold
• The leaf blade thickens and midrib turns yellow and curl
• Finally infected leaf turns to reddish purple tint
• The reddish velvety surface of lamina is soon covered with a whitish grey bloom of the fungus on the upper surface
• Both the leaves and petiole may curl
• Affected leaves die and drop immaturely
• Twigs become pale green to yellow, swollen, stunted and exude gummy material
• Flowers and fruits are also infected & drop prematurely


Etiology

• Mycelia are intercellular and not produce specific ascocarp.
• Asci are produced (Open ascus) individually and measure 25to 40 x 8 to11 µm. Each ascus bears eight ascospores of 3 to 7µm diameter.
Epidemiology

• The disease is prevalent in areas where cool and misty spring weather prevails and the dry hot weather hastens defoliation
• Primary source of inoculum: Dormant mycelia in the affected stem newly formed buds.
• Secondary source of inoculum: Air borne conidia.
Management

• Removal & burning of infected leaves and shoots reduce the spread of the disease
• A dormant spray with Bordeaux mixture (1%) with an adhesive and a winter spray with Bordeaux mixture (1%) before bud burst controls the disease.