Phytoplasma and spiroplasma collectively causes a number of diseases are referred to as –

Correct option is C

Correct option (c) Yellow disease
· Phytoplasma and spiroplasma infections typically cause:
· Yellowing
· Little leaf
· Witches’ broom
· Hence grouped as yellows diseases.
Other options:
· (a) Wilt disease – Mainly fungal/bacterial.
· (b) Mosaic disease – Viral in nature.
· (d) Mottle disease – Virus-induced symptom.