Question

A common biocontrol agent for plant diseases is ______.
a. Bacillus thuringiensis
b. Glomus
c. Trichoderma
d. Baculovirus

Answer 1

Hint: There are lots of diseases that affect plants, animals and human beings. Here, particularly in plants we use pesticides to protect it. Apart from pesticides we use a greater number of biocontrol agents. These are the agents that protect plants from the parasites. They help in the infestation of the pests. Here, the most common biocontrol agent which is used for plant diseases can be found and analyzed.

Complete answer:
Biocontrol agents are those which are used for the control of the pest by using biological agents and microorganisms. This is used to get pest free fields. This is a very effective one. These are specific only to the harmful organisms and do not affect any of the useful organisms that are present in the soil. Biocontrol agents have both advantages and disadvantages. They are as follows:

Merits:
- They are cost-effective
- It reduces the use of chemicals and pesticides.
- This is effective in all the seasons.

Demerits:
- This affects the product quality
- The pest is not removed completely
- Not very much effective for short scale application.

Here, Bacillus thuringiensis is the gram-positive bacterium that is used as the biological reagent. This is the effective control agent in many of the crops. This is present in the soil and not poisonous to humans. Glomus is a mycorrhizal fungus. This is the largest fungi. They are solitary and multicentric. Currently, it is declared as non-monophyletic. Trichoderma is the genus of fungi that can grow on the roots. Many species in these fungi can be characterized as opportunistic avirulent plant symbionts. These are the most common biological agents. Baculovirus are those which come under the DNA virus family that infects invertebrate animals. They improve solubility and higher yields of security proteins.

Hence, the correct answer is option (C).

Note: Trichoderma forms symbiotic association with the plants. These are commonly used in the root infections. They are used for preventing foliar disease. They do not cause any harm to the plants but they suppress the infection by other species of fungi. These are the popular agents that are used to protect the crops against the pathogens all over the world.