Abstract
Viability of encyysted eggs and larvae of Heterodera glycines stored in soil up to 11 years was studied. Two cyst-containing soil samples were taken from nematode-infested soybean fields. One sample was air-dried (soil moisture : 7.0%) and the other was not dried (soil moisture : 25.9%). The soli were held in plastic bags and stored in a room without any temperature control. Viability examinations done every year revealed that the encysted eggs of this nematode were able to survive for 9 years in the air-dried conditions and to infect soybean roots for 7 years in both cases of the moisture conditions.