The effect of storage time and temperature on the population dynamics and vitality of Meloidogyne chitwoodi in potato tubers

The population densities of Meloidogyne chitwoodi in potato tubers stored at 4, 8 and 12°C after 0, 60, 120, 180 and 240 days of storage were assessed. Compared to day 0, storage temperatures of 4 and 8°C reduced population densities to 9 and 35%, respectively, after 240 days of storage, while nematode numbers in tubers stored at 12°C increased 2.5 times. The maximum hatching rate of nematodes from tubers stored at 8 and 12°C increased linearly with storage time. At 4°C it remained constant. The time required for the hatching process to reach the maximum number of second-stage juveniles (J2) decreased with increasing storage temperature. Recovered juveniles of M. chitwoodi from tubers after 180 and 240 days of storage at all three temperatures were still infective and able to multiply on 'Desiree' with estimates of the maximum multiplication rate (a) and the maximum population density (M) of 63.6 and 70.8 J2 (g dry soil)-1, respectively.