How to confirm it is disease or a pest

[khabbab]

If i am unable to see a pest on the leaves then it is surely a disease? For example If leaves are wilting and there is no pest i can see does it mean it will be a disease?

What are the general plant diseases? I know pests and their cure but how to know which disease my plant is suffering from?

[M Farooq]

If i am unable to see a pest on the leaves then it is surely a disease? For example If leaves are wilting and there is no pest i can see does it mean it will be a disease?

What are the general plant diseases? I know pests and their cure but how to know which disease my plant is suffering from?

A picture would be highly helpful. Fungus is also possible but it is visible as well. May be the plant roots are decaying but again picture is worth a thousand words.

[khabbab]

Actually it is not a problem with my plant, i just want to know(for knowledge purposes) how to differentiate between a pest and a disease? If i post picture, how would you determine whether it is a pest of disease? Leaf shape? Leaf color?

[M Farooq]

Actually it is not a problem with my plant, i just want to know(for knowledge purposes) how to differentiate between a pest and a disease? If i post picture, how would you determine whether it is a pest of disease? Leaf shape? Leaf color?

Khabbab it is then a very difficult question; The causes of the plant being unhealthy are so varied that probably only a plant pathologist can identify after diagnostic tests. There are plant viruses which cause many diseases and we will not be able see any pest. There are certain pests which live inside the leaves. So they are not visible on the top side or the bottom of the leaves. Similarly if the plant is suffering from a fungal disease we would not be able to see "pests".

I think the simple test would be to examine the plant very carefully, leaves & stems to see moving creatures. There may be root eating nematodes in the soil. If you notice no foreigners on the plant and still the plant is dying then it might be a disease from fungus/ virus / bacteria etc. Have you seen plant tumours on "bair" tree (Zizyphus jujuba) on the stems? Pretty common ... but this is typically by bacterial infections.

Regards,

Farooq