Name the causative micro-organisms of the following plant diseases :
(a) Rust of wheat (b) Citrus canker (c) Yellow vein mosaic of bhindi (Okra)
Part (a): Rust of wheat is the disease that damages the wheat grains due to infection caused by fungi.
Part (b): Citrus canker is a bacterial disease that affects the citrus plants and fruits.
Part (c): Yellow vein mosaic of bhindi is caused by a viral pathogen.