Tristeza or quick decline: Citrus tristeza virus (CTV)

Symptoms

• 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.
• Roots decay, 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 very much reduced. Fruits are small in size.
  Use of infected bud wood and 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.