Question

Explain the importance of biopesticides in organic farming.

Answer 1

Hint: Biopesticides are produced from toxins found in biological organisms that are harmful to the pests that invade plants. They do not affect the plant and in fact, reduce soil pollution and erosion. Hence, organic farming requires biopesticides for good crop production.

Complete answer:
 - Biopesticides are pesticides obtained from biological agents and organisms that are toxic to pests that invade crops.
- They work against various insects, weeds, and nematodes.
- These pesticides can be naturally occurring in the microorganisms or can be induced genetically in the plants through genetic engineering.
- Usage of biopesticides prevents soil pollution and contamination from various chemicals like fluoroacetamide. They also have a lower chance of causing skin irritation in humans and animals.
- Chemical fertilizers have broad specificity, that is, they tend to kill a large population of pests but may also kill beneficial insects like pollinators. Biopesticides are specific for particular weeds and pests, hence they do not harm other neighboring species.
- Following are the examples of biopesticides:
1. Bacillus thuringiensis that causes intestinal diseases of various lepidopteran, coleopteran, and dipteran species. The toxin from this bacteria has also been directly expressed in plants through genetic engineering, such as Bt cotton and Bt brinjal.
2. Trichoderma, a plant root fungus, acts as a biocontrol agent against several plant pathogens

Additional Information: - Biopesticides can be classified as 1. Microbial pesticides consisting of bacteria, fungi, viruses, and sometimes nematodes.
2. Bio-derived chemicals that are various substances naturally occurring that control pest populations such as neem oil and other aromatic compounds.
3. Plant-incorporated protectants or Genetically Modified (GM) crops.
4. RNAi (RNA interference) pesticides. Some of them are applied topically on plants and are absorbed by them.

Note: - Biopesticides can be obtained from byproducts of fermentation, for example, spinosad obtained from sugarcane fermentation.
- Some substances derived from plant extracts such as canola and garlic also have shown pesticidal properties.