Question

What is Trichoderma harzianum used for in agriculture?

• A. Nitrogen fixation
• B. Biocontrol of fungal plant pathogens
• C. Phosphorous solubilization
• D. Weed control

Hint:

Remember:
• Trichoderma \(\rightarrow\) Biocontrol fungus
• Rhizobium \(\rightarrow\) Nitrogen fixation
• Phosphate-solubilizing microbes \(\rightarrow\) Increase phosphorus availability \[ \textit{Trichoderma} = \text{Eco-friendly protection against fungal diseases} \]

Answer 1

The Correct Option is B

Concept: Trichoderma harzianum is a beneficial fungus widely used in agriculture as a biocontrol agent. It protects plants against harmful fungal pathogens by:
• Competing for nutrients and space
• Producing antifungal compounds
• Parasitizing pathogenic fungi
• Stimulating plant defense mechanisms Thus, it plays an important role in sustainable and eco-friendly agriculture.

Step 1: Identifying the agricultural role of Trichoderma harzianum. Trichoderma harzianum is mainly used to control fungal diseases affecting crops such as:
• Root rot
• Wilt diseases
• Damping-off disease Therefore: \[ \boxed{\textit{Trichoderma harzianum} \text{ is used for biocontrol of fungal plant pathogens}} \]

Step 2: Eliminating the incorrect options.
• Option (A): Nitrogen fixation is carried out by microorganisms such as Rhizobium and Azotobacter.
• Option (C): Phosphorous solubilization is mainly performed by phosphate-solubilizing bacteria and fungi like Pseudomonas and Aspergillus.
• Option (D): Weed control is generally achieved using herbicides or biological weed-control agents, not Trichoderma harzianum. Hence, the correct answer is option (B).