Elaborate the following : 
VAM 

Expand the following:

DDT

(a) Describe the procedure of hybirdisation in plants.

(b) Name the causative agent and the main preventive measure for each of the following diseases:

(i) Amoebiasis
(ii) Rabies

(iii) Pneumonia

(c) What is manure? Explain any two types of manures.

Give reasons for the following:                                                                      
Nitrogenous fertilisers are not applied in fields where leguminous crops grow.