Question

Fungicides and antimicrobials are the chemicals that
(a) Enhance yield and disease resistance
(b) Kill pathogenic fungi and bacteria respectively
(c) Kill all pathogenic microbes
(d) Kill pathogenic bacteria and fungi respectively

Answer 1

Various types of chemicals are used to kill the bacteria and fungi by inhibiting their mechanism of growth. Those chemicals are named after the organisms. The term cidal in the suffix indicates killing.

Complete answer:
In agriculture, fungi cause serious damage to the crop and are responsible for reducing the yield of the crop. Farmers, in order to get rid of fungi, use certain chemicals that kill the fungi or the spores produced by the fungi. Those chemicals are called fungicides. Apart from fungi, microorganisms like bacteria also cause various types of disease in both plants and animals either directly entering into the body or by contaminating food and water. To kill the bacteria certain types of chemicals are used called bacteriocides.

Additional information:
- The chemicals which are used to kill fungi are also used to kill oomycetes because they use the same mechanism of action as fungi to affect the organism. They are called fungicides.
- If the chemicals used for fungi just inhibit their growth, then those chemicals are called fungistatic.
- If the chemicals used on bacteria just to inhibit their growth, then they are called bacteriostatic.
Bacteriocides can be available in different forms like disinfectants, antibiotics, and antiseptics.
So, the correct answer is ‘(b) Kill pathogenic fungi and bacteria respectively’

Note:
- The most common active ingredient used in fungicides is sulfur and is sold in liquid form.
- Some of the fungicides like vinclozolin, ziram are toxic to humans.
- Some of the examples of bacteriocides are disinfectants: active chlorine, active oxygen, iodine, concentrated alcohol; antibiotics: penicillins, tetracyclines, cyclosporins; antiseptics: rectified spirit, iodine, alcohols.