Which of the following can be used as a biocontrol agent in treatment of Plant diseases?

Step-by-step solution

Trichoderma is one of the most abundant fungi that have been shown to be present in all climatic zone's soil. Among all the biocontrol agents, Trichoderma sp. like Trichoderma harzianum is the most abundantly used against plant pathogens. Many species of Trichoderma produce volatile and non-volatile antibiotics and enzymes which are antagonistic to phytopathogenic fungi and nematodes.