Question

Chemical substance used to kill insects is
A. Fungicide
B. Insecticide
C. Weedicide
D. All of the above

Answer 1

Hint: Insects help plants in pollination and increase crop productivity. However, certain insects damage crop plants. They feed and grow over the crop plants and destroy the crops. Therefore, several chemical substances are used to kill them and eradicate them to protect the crops.

Complete answer: Let us look at all the options that are given to us one by one.
-Fungicide: Fungicide is the chemical substance that is used to eradicate fungus and fungal infections from the plants. Several fungi are pathogenic to the plants and cause various kinds of diseases. These diseases hamper the normal growth of the plant. They damage certain organs of the plants. Due to this reason, the plant usually dies. Thus, Fungicides are sprayed over the plants to protect them from the attack of fungi and fungal infections. Fungicides are chemical substances. They inhibit the growth of fungi.
-Insecticide: The insecticide is the chemical substance that is used to eradicate insects from the plants. Several insects are pathogenic to the plants and cause various kinds of damages to the crops. These insects feed on the crops and damage the plants. Due to this reason, the crop yield decreases. Thus, Insecticides are sprayed over the plants to protect them from the attack of insects. Insecticides are chemical substances. They kill the insects attacking the crops.
-Fungicide: Weedicide is the chemical substances that are used to eradicate the weed from the plants. Weeds are unwanted plants. They grow with other plants and consume the nutrition of their share. Due to this reason, the crop plant has stunted growth and it becomes weak and usually dies. Thus, weedicides are sprayed over the plants to protect them from the attack of weeds. Weedicides are chemical substances. They inhibit the growth of the weeds so that the crop plant can grow properly.
Thus, based on the above information we can conclude that chemical substances used to kill insects are known as the Insecticides.
Hence, the correct answer is option (B).

Note: The chemical substances that are sprayed over the crop plants save them from various kinds of diseases and plant pathogens and predators. However, they are very harmful to human or animal consumption. These chemicals cause biomagnification and eutrophication. Therefore, the use of biological agents to control plant pathogens is being used and promoted nowadays. These substances are known as Biopesticides. They are completely natural and biological substances.