EU Pesticide Regulation Likely to Severely Reduce UK Potato Production International Pesticide Benefits Case Study No. 92, October 2013

The white and golden potato cyst nematodes (PCN) are the most economically important pests of potato in the UK [3]. Potato cyst nematodes originated in the Andes, where they coevolved with the potato. The earliest reports of PCN in the UK were in 1913. PCN were reported increasingly in the UK from 1920 onwards. In 1946, 20 % of the potato acreage was estimated to be infected while surveys in 1996 and 2002 determined that 42 % and 64 % of the potato fields were infested, indicating a significant recent increase in the problem [2]. It is probable that a substantial portion of the remainder are “incubating ” infestations too small to detect [4]. Nematodes are round microscopic (.004-.04 inches in length) unsegmented worms (not true worms). Roots of infected plants contain minute, white bodies of female nematodes that have erupted through the roots. When a female dies, its cuticle forms a protective cyst containing 200 to 500 eggs [1]. Cysts containing viable eggs can persist in the soil for up to twenty years. When potatoes are planted, root exudates stimulate 60 to 80 % of the juveniles to emerge from eggs. The juveniles locate and enter roots. They cut through cell walls and feed. After a final molt, the adult males emerge through the root. The females rupture the root so that their bodies protrude. They release a substance that attracts males, which mate with them repeatedly [1]. Embryos develop inside eggs into juveniles; the female