Key Facts
• In early April 2026, Aichi Prefectural Agricultural Research Center confirmed beet cyst nematode in cabbage fields in Higashi Mikawa region.
• Identification was done by the Ministry of Agriculture, Forestry and Fisheries Nagoya Plant Protection Station.
• First domestic detection was in Nagano Prefecture in September 2017; Yamanashi Prefecture confirmed cases in 2023.
• Cysts are lemon-shaped, brownish, 0.5–0.9 mm long, 0.3–0.6 mm wide, containing eggs and second-stage larvae.
• Female adults are white, lemon-shaped, similar in size to cysts; males are threadlike.
• Eggs hatch stimulated by host root secretions; larvae invade roots, causing multinucleation and nutrient absorption.
• Females embed in roots, produce 1–600 eggs, then harden into cysts that survive long in soil without hosts.
• Spread occurs via contaminated soil on farm equipment and natural elements like wind and rain.
• Damage includes poor growth, wilting, and yield reduction in Brassica crops; abnormal root hairs and severe yield loss in sugar beet.
• Host plants include Brassica species (cabbage), Beta species (sugar beet), spinach, rhubarb, and tomato underground parts.
• Control measures: clean farm equipment before moving, avoid moving crop residues off fields, soil disinfection with D-D agents, and crop rotation with beans or rye to reduce nematode density by 30–60% annually.
Summary
The Aichi Prefectural Agricultural Research Center has confirmed the first occurrence of beet cyst nematode in cabbage fields within the prefecture, marking a significant agricultural concern. This pest, previously detected in Nagano in 2017 and Yamanashi in 2023, forms resilient cysts that survive harsh conditions and spread through contaminated soil and equipment. The nematode parasitizes roots of various crops, notably Brassica and Beta species, causing stunted growth, wilting, and substantial yield losses. Despite its impact on plants, it poses no health risk to humans or animals. Effective management includes thorough cleaning of agricultural machinery, preventing residue transfer, soil treatment with nematicides, and crop rotation with recommended plants like beans and rye to reduce nematode populations. These measures aim to prevent further spread and protect crop productivity in Aichi and beyond.
