Spiral nematode

Systematic position: Helicotylenchus pseudodigonicus belongs to the phylum Nematoda, class Chromadorea, order Rhabditida, and family Hoplolaimidae. These microscopic organisms are recognized as significant ectoparasites that interact closely with the root systems of various plant hosts.

Host range: This nematode species acts as a polyphage. It infests a diverse array of crops including cereals, legumes, various vegetables like tomatoes and potatoes, as well as several fruit-bearing trees. The infestation severity depends largely on the soil type and host susceptibility.

Biology and life cycle: The nematode follows a semi-endoparasitic life cycle. It consists of the egg stage, four larval stages, and the adult stage. The duration of the life cycle is highly dependent on environmental factors, specifically soil moisture and temperature, with rapid development occurring during warm growing seasons.

Nature of damage and economic impact: Feeding on root cells results in tissue necrosis and root system inhibition. The direct damage stunts plant growth, reduces nutrient uptake, and causes chlorosis of leaves. Furthermore, these wounds act as entry points for secondary pathogens, often leading to complex disease syndromes that significantly decrease total yields.

• Implementing strict crop rotation practices with non-host species.
• Using certified nematode-free seeds and seedlings.
• Applying nematicides when pest population densities exceed economic thresholds.
• Improving soil drainage and structure to limit nematode mobility.
• Managing weeds that may act as alternative hosts in the field.