Stem and bulb nematodes

Affected crops. These nematodes are polyphagous and represent a significant threat to a wide range of agricultural and horticultural crops. Their primary hosts include garlic, onions, potatoes, strawberries, and various flower bulbs like tulips and daffodils. They can also affect several forage crops, causing widespread damage in both fields and storage facilities.

Biology and life cycle. The life cycle involves an egg stage, four larval stages, and an adult stage. Reproduction typically occurs within the host tissue. A critical aspect of their biology is the ability to enter anhydrobiosis (a state of dormant dehydration), which allows the nematodes to survive for several years in soil or dried plant debris, waiting for moisture to become active again.

Damage and pathogenicity. Feeding by Anguinidae causes distinctive symptoms such as stem twisting, swelling, and shortening of internodes. Leaves may become thickened and wrinkled. In bulbs and tubers, the tissue becomes spongy, necrotic, and prone to decay. This leads to stunted plant growth, reduced yields, and massive losses in storage as infected crops succumb to rot.

Control measures. Integrated Pest Management (IPM) is essential for controlling these nematodes, as direct chemical intervention is often difficult. Key strategies include:

• Utilizing nematode-free planting stock and certified seeds.
• Implementing long-term crop rotation with non-host crops.
• Strict field sanitation, including the removal and destruction of crop residues.
• Thermal treatment of bulbs and seeds to eliminate dormant larvae.
• Monitoring soil health and encouraging beneficial microorganisms that suppress nematode populations.