Previous Year Question

Plant diseases spread when the infectious parts of a pathogen move from one place or plant to another place or plant.

These infectious parts may include fungal spores, bacteria, viruses, nematodes and infected plant tissues.

Birds can transport pathogens from one place to another through their beaks, feet, feathers or droppings.

Birds that consume infected fruits and seeds can also become carriers of certain pathogens.

Therefore, birds can be responsible for the dissemination of plant diseases.

Soil particles and the fungal spores, bacteria and other pathogens present on them can also be transported with blowing dust.

This medium particularly assists the dissemination of pathogens present in soil and plant debris.

Raindrops can splash pathogens from infected leaves, stems and soil onto nearby healthy plants.

This process is known as raindrop splash or rain-splash dissemination.

Through this process, many bacterial and fungal diseases spread over short distances within a field.

Blowing wind can carry light and microscopic fungal spores over long distances.

Wheat rust, powdery mildew and several other airborne diseases can spread rapidly in this manner.

Wind can also transport infected plant tissues and pathogen-bearing dust from one place to another.

The actual distance of disease dissemination depends on the nature of the pathogen, weather, humidity and wind speed.

Therefore, birds, blowing dust, rain and blowing wind—all four can be responsible for the dissemination of plant diseases.