17. Answer briefly V

 

a. Microorganisms are called fertilisersdecomposers because they act upon degradable wastes. During the process, nitrates and other inorganic nutrients are released into the soil, making the soil fertile. This compost is called bio-control agentsnatural fertilizer.

 

b. RhizobiumTrichoderma bacteria found in the root nodules of leguminous plants enrich the soil by fixing nitrogen from the atmosphere as nitritenitrates, which are necessary for plant growth.

c. BaculovirusesBacillus thuringiensis aids in the prevention of  insect control.

 

d. TrichodermaBaculoviruses aids in root protection and control of plant pathogens.