UPSC MainsAGRICULTURE-PAPER-II201215 Marks200 Words
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Q15.

Microbial pesticides and their use in agriculture

How to Approach

This question requires a nuanced understanding of microbial pesticides, moving beyond a simple definition. The approach should involve defining microbial pesticides, highlighting their advantages over chemical pesticides, discussing different types (bacteria, fungi, viruses), explaining their mode of action, and addressing limitations/challenges in their adoption. A brief mention of the regulatory framework and future prospects would also be beneficial. Structure: Definition, Types & Mode of Action, Advantages, Challenges, Future Prospects.

Model Answer

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Introduction

The escalating concerns regarding the detrimental effects of chemical pesticides on human health and the environment have spurred the development of biopesticides, with microbial pesticides gaining prominence. These are derived from microorganisms like bacteria, fungi, and viruses, offering a potentially more sustainable alternative. India, being an agrarian economy, faces significant challenges in pest management, making the adoption of such eco-friendly solutions crucial. The question asks us to delve into the specifics of microbial pesticides, examining their utility and limitations in modern agriculture.

What are Microbial Pesticides?

Microbial pesticides are biological control agents derived from bacteria, fungi, viruses, or protozoa that control plant diseases and insect pests. They are a subset of biopesticides, which also include botanical pesticides and insecticidal nematodes. Unlike synthetic pesticides, they are often more target-specific and break down quickly, minimizing environmental persistence.

Types and Mode of Action

Microbial pesticides can be broadly categorized based on the microorganism used:

  • Bacteria: Bacillus thuringiensis (Bt) is the most widely used, producing toxins that affect insect larvae. Bacillus subtilis produces antibiotics effective against fungal pathogens.
  • Fungi: Beauveria bassiana and Metarhizium anisopliae are entomopathogenic fungi, meaning they infect and kill insects.
  • Viruses: Nuclear polyhedrosis viruses (NPVs) are host-specific and target insect larvae.
  • Protozoa: Less common, but some protozoa can be used to control specific pests.

The mode of action varies. Some, like Bt, produce toxins upon ingestion. Others, like fungi, infect the insect cuticle and penetrate tissues. Viruses typically cause occlusion of larval digestive systems.

Advantages of Microbial Pesticides

Microbial pesticides offer several advantages over synthetic alternatives:

  • Target Specificity: They often target specific pests, minimizing harm to beneficial insects and pollinators.
  • Reduced Environmental Impact: They are generally less persistent in the environment and pose lower risks to non-target organisms.
  • Lower Toxicity: Generally safer for humans and wildlife compared to synthetic pesticides.
  • Resistance Management: Can be integrated into resistance management strategies to delay the development of resistance in pest populations.

Challenges and Limitations

Despite their benefits, microbial pesticides face challenges:

  • Lower Efficacy: Often less potent than synthetic pesticides, requiring higher application rates or multiple applications.
  • Environmental Sensitivity: Their effectiveness can be affected by environmental factors like UV light, temperature, and humidity.
  • Mass Production and Storage: Production can be complex and requires specialized facilities. Storage and shelf-life can be problematic.
  • Cost: Production and formulation costs can be higher, making them less accessible to smallholder farmers.
  • Public Perception: Some farmers may be hesitant due to concerns about efficacy or unfamiliarity.

Future Prospects & Regulatory Framework

The future of microbial pesticides lies in advancements such as:

  • Genetic Engineering: Improving efficacy and broadening host range.
  • Formulation Technology: Enhancing stability and delivery.
  • Combination Products: Combining microbial pesticides with other control methods.

In India, the Insecticides Act, 1968, regulates the registration and use of pesticides, including microbial pesticides. The Central Insecticides Board & Registration Committee (CIBRC) is responsible for their evaluation and registration. The National Biodiversity Authority (NBA) also plays a role in ensuring compliance with biodiversity regulations.

Pesticide Type Advantages Disadvantages
Synthetic High Efficacy, Broad Spectrum Environmental Persistence, Toxicity
Microbial Target Specificity, Reduced Environmental Impact Lower Efficacy, Environmental Sensitivity

Conclusion

Microbial pesticides offer a promising pathway towards sustainable pest management in agriculture, reducing reliance on harmful chemical pesticides. While challenges regarding efficacy and cost remain, ongoing research and technological advancements are steadily improving their performance. Government support, farmer education, and integrated pest management strategies are crucial to facilitating wider adoption and realizing the full potential of these eco-friendly alternatives for ensuring food security and environmental sustainability.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Biopesticide
Pesticides derived from natural sources, including microorganisms, plants, and minerals. They are generally considered to be less harmful to the environment than synthetic pesticides.
Entomopathogen
An organism, typically a fungi, bacterium, virus, or nematode, that is pathogenic to insects. These are often used as biopesticides.

Key Statistics

The global biopesticides market was valued at USD 4.6 billion in 2023 and is projected to reach USD 8.5 billion by 2030, growing at a CAGR of 9.2% from 2023 to 2030. (Source: Allied Market Research, 2023)

Source: Allied Market Research

India accounts for approximately 25% of the world's total pesticide consumption. (Source: Ministry of Agriculture & Farmers Welfare, Knowledge Cutoff)

Source: Ministry of Agriculture & Farmers Welfare

Examples

Bt Cotton

Bt cotton, genetically modified to produce the Bt toxin from <em>Bacillus thuringiensis</em>, is widely cultivated in India and other countries to control bollworms. While it has reduced insecticide use, resistance is a growing concern.

Frequently Asked Questions

Are microbial pesticides completely safe?

While generally safer than synthetic pesticides, microbial pesticides are not entirely without risk. Some can cause allergic reactions in sensitive individuals. Thorough risk assessments are still necessary before registration and use.

Topics Covered

AgricultureEntomologyEnvironmentPest ControlBiocontrolSustainable Agriculture