Context

• In a globalised world, plant pathogens are causing multiple outbreaks, thereby hampering food security.

Plant Pathogens

• Pathogens include fungi, bacteria, nematodes, and viruses, all biological organisms that can cause disease symptoms and significantly reduce the productivity, and even cause the death of plants.
• Pathogens can spread through insect vectors, infected seeds, transplants, contaminated equipment, irrigation water, and humans.
• Major plant diseases include wheat blast, canker, coffee leaf rust, rice blast, late blight etc.

Plant Disease Triangle

• Plant pathologists have identified three factors that are needed for a plant disease to develop,
  • A Susceptible Host – Some pathogens have a narrow host plant range, meaning they can infect just a few host species. For instance, the primary host crops of Late blight are tomato and potato. By contrast, pathogens with a wide host plant range can infect many different host species. Ex: Bacterial wilt can infect over 200 plant species.
  • A Pathogen – They are disease causing organisms and can include fungi, bacteria, viruses, and nematodes.
  • A favorable environment – Pathogens usually require specific humidity and temperature conditions for disease symptoms to manifest. Ex: Late Blight disease symptoms are most likely to occur when the weather is cool and wet.

Findings

• According to FAO, 40% of the yield of economically important crops is lost each year due to plant pathogens and pests. 
• The losses associated with plant disease carry a high economic burden, with an estimated annual loss of $220 billion dollars.
• As per a recent research, a rise in global warming from 1.5°C to 4 °C is expected to increase the territorial spread of several plant diseases across the world.

Implications of Plant Pathogens on Food Security

• • Reduced Crop Yields: Plant Pathogens can hinder plant growth and productivity thereby significantly reducing crop yields. For example, the late blight caused by Phytophthora infestans led to the Irish Potato Famine in the 19th century.
  • Economic Losses: Farmers incur significant losses due to the cost of managing diseases, purchasing fungicides, bactericides,etc thereby reducing the profitability of farming.

• Increased food prices: Reduced supply of food garins due to crop losses leads to higher food prices making  food less affordable, especially for low-income populations.

• Disruption of Trade: Trade restrictions imposed to prevent the spread of plant pathogens can disrupt food imports and exports, thereby affecting food supply.

Measures to curtail the spread of Plant pathogens

• • Quarantine Regulations: It is important to implement strict quarantine regulations and inspections to detect and eliminate contaminated plant material.
  • Biological Control: Pathogen populations can be controlled effectively by using natural predators, parasites, or antagonistic microorganisms.

• Genetically modified crops: Through novel innovations of biotechnology it is important to promote the use of GM crops that are resistant to pests and diseases.

• Early Detection Systems: It is important to make use of remote sensing technologies and Geographic Information Systems (GIS) to monitor and predict disease outbreaks.

Conclusion

• Coordinated effort and active surveillance are esssential to curtail the territorial spread of  pathogens in a warming world.