Lime is susceptible both as seedling or buddling on any root stock. But mandarin and sweet orange seedlings or on rough lemon, trifoliate orange, citrange; Rangpur lime root stocks tolerant; susceptible root stocks are grapefruit and sour orange. In sweet orange or mandarin on susceptible root stocks, leaves develop deficiency symptoms and absise. Rootsdecay, twigs die back. Fruit set diminishes; only skeleton remains. Fine pitting of inner face of bark of sour orange stock. Grapefruit and acid lime are susceptible irrespective of root stock. Acid lime leaves show large number of vein flecks (elongated translucent area). Tree stunted and dies yield verymuch reduced. Fruits are small in size. Use of infected bud wood and Toxoptera citricida (aphid) is the important vector.
Pathogen
Citrus tristeza virus is long, flexuous rod and measure 2000x 12nm in size. Three strains viz., mild, severe and seedling yellow are reported.
Mode of spread
Use of infected bud wood Toxoptera citricida (aphid) is the important vector.
Management
For sweet orange and mandarin, avoid susceptible root stocks. For acid lime, use seedling preimmunised with mild strain of tristeza.