Control of potato cyst‐nematode, Globodera rostochiensis Rol, by picrolonic acid and potato trap crops

SUMMARY Small, sprouted tubers of potatoes (cv. Pentland Crown) grown for 6 wk and then pulled out of soil infested with potato cyst‐nematode, Globodera rostochiensis Roi, increased the hatch of larvae, so that 100 days after planting the top 20 cm of the soil contained only one third of the original number of eggs. The artificial hatching agent picrolonic acid alone at 8‐6, 17*2 or 34‐4 kg/ha rotavated into the soil did not increase hatch but 17*2 kg, incorporated in the soil after potatoes grown for 4 wk, did.