Disease:Amaranthus aphid borne mosaic

Amaranthus aphid borne mosaic poty virus (CabMV)

Black eye cow pea mosaic poty virus (BICMV)

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Symptoms

  • Initially the young trifoliate leaves show chlorosis irregularly.
  • Gradually, the extent of chlorotic areas increases.
  • Soon leaves show mosaic mottling, vein banding, puckering and distortion.
  • Severe infection results in considerable reduction of the size of new leaflets and also blistering and bleaching of leaves.
  • The pods are also twisted, curved and reduced in size.
  • The seeds in these pods are shriveled and few in number.

Epidemiology

The virus belong to poty virus group and are transmitted by aphids in a non - persistent manner. Three species of aphids namely Myzus persicae, Aphis gossypii and A.craccivora are found to be the most efficient vectors. The virus perpetuates on several other hosts that includes both crop plants and weeds.

Procedure for Observation

Select 25 plants at random and observe for mosaic symptoms

ETL

  • Mere presence

    • Control Measures

  • Collect seeds from healthy, disease free plants.
  • Manage vectors by spraying insecticides like malathion 50 E.C. (2ml/L), quinalphos 25E.C. (1.25 ml/L), or, neem oil emulsion (This is done by dissolving 60 g bar soap in 500 ml water and blending 1 L. neemoil into it and diluting the mixture 10 times). Spraying should be directed to the under surface of leaves and other parts of the plant. (i.e., stem, flower, pods, etc) The best method is to use resistant varieties .