Awl Nematodes (Dolichodorus spp.) Plant Disease

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Awl Nematodes (Dolichodorus spp.) Plant Disease 

Dolichodorus spp., commonly known as awl nematodes, are plant-parasitic nematodes.


  •   Kingdom: Animalia
  •   Phylum: Nematoda
  •   Class: Secernentea
  •   Order: Dorylaimida
  •   Family: Longidoridae
  •   Genus: Dolichodorus

Distribution:

  • Found in sandy soils of tropical, subtropical, and temperate regions.
  • Commonly associated with turfgrasses, agricultural crops, and nursery plants

Host Plants:

  • Wide Host Range: Awl nematodes can infect a variety of plants, including:
    • Crops: Corn, soybeans, potatoes, and vegetables.
    • Turfgrasses: Golf courses and lawns.
    • Ornamentals: Many nursery and garden plants.

Symptoms in Plants:

  • Stunted Growth: Infected plants often show poor growth due to the nematode feeding on the root tips.
  • Wilted or Yellowing Leaves: Plants may wilt or develop yellow leaves due to reduced water and nutrient uptake.
  • Stubby Roots: Roots appear short, stubby, and poorly developed, leading to poor anchorage and plant instability.
  • Root Necrosis: The root tips may show blackening or rotting, leading to reduced root function.
  • Poor Plant Vigor: Infected plants are generally less vigorous and are more prone to other stress factors like drought and nutrient deficiencies.

Pathogenicity:

  • Feeding Habits: Awl nematodes feed on the root tips of plants, causing severe damage to the root system.
  • They puncture root cells and feed on their contents, leading to cell death and the characteristic "stubby root" symptoms.
  • Injury to Roots: Their feeding also creates entry points for secondary infections by soil-borne fungi and bacteria.

Disease Cycle:

  1. Nematode Eggs Hatch in the soil.
  2. The juvenile nematodes locate plant roots and begin feeding on the root tips.
  3. Adult nematodes continue feeding and reproducing, further damaging the plant.
  4. Eggs are laid in the soil, continuing the cycle.

Environmental Factors:

  • Sandy Soils: Awl nematodes thrive in sandy soils where water movement is high, and plant roots are more easily accessible.
  • Warm Climates: They are more active in warm conditions, which promote faster reproduction and greater nematode populations.

Management Strategies:

  1. Cultural Practices:
    • Crop Rotation: Rotate with non-host crops to reduce nematode populations in the soil.
    • Soil Amendments: Add organic matter or compost to the soil to improve structure and water retention, which can make it less favorable for nematode survival.
  2. Nematode-Resistant Varieties:
    • Use plant varieties that are resistant or less susceptible to awl nematodes where available.
  3. Chemical Control:
    • Nematicides: In areas of severe infestation, nematicides can be applied to reduce nematode populations.
    • Use caution with chemical treatments, considering environmental regulations and the potential impact on beneficial soil organisms.
  4. Sanitation:
    • Remove and destroy infected plant material.
    • Ensure that planting materials, like turfgrass sod or seedlings, are nematode-free.
  5. Biological Control:
    • Introduce or encourage beneficial nematodes or soil organisms that can prey on or compete with plant-parasitic nematodes.
  6. Monitoring and Soil Testing:
    • Regularly monitor nematode populations through soil sampling and testing, especially in high-risk areas like sandy soils

 

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