Citrus tristeza
Causal organism: Citrus tristiza virus Symptoms
- Leaf: Chlorosis is the common symptom followed by leaf size reduction, leaves fall and die back of defoliated twigs.
- Stem: Bark eruption and pittings on stem (V shaped depression on the stem and stem twisting occurs.)
- Fruits: In the affected fruits, thicknesss of the rind is increases and, mesocarp decreases.
- Root stocks are susceptible, phloem necrosis is the common symptom, root discoloration and root decay occurs which leads to sudden leaf dropping.
Epidemiology
- Primary source of inoculum: infected plants and cuscuta
- Secondary source of inoculum: Vectors (aphids) (Toxoptera citricida), infected implement used for grafting/budding.
Management
- Use the seedlings developed from seeds for transplanting.
- Use a rough lemon root stock and other scion so as to, protect plants from phloem necrosis.
- Cut and burn the infected parts.
- Replanting with resistant plants in a phased manner.
- Hot water treatment of rootstocks at 450 C for 10-25 minutes.
- Removal of cuscuta and spraying with systemic insecticides like Dimethoate (2ml/lt) controls the aphid vector population.
- Apply recommended dose of N P K and FYM.
- Heat treatment
- Cross Protection: Use pre-immunized seedlings with mild strain of the virus so as to manage the disease and avoid losses.
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Last modified: Friday, 20 January 2012, 1:31 PM