Population Dynamics and Generation Cycle of Meloidogyne hapla on Codonopsis pilosula

Purpose To clarify the population dynamics and generation cycle of Meloidogyne hapla on Codonopsis pilosula in Gansu Province, providing a theoretical basis for timely and effective control of the disease.

Methods In 2021, soil and root samples were periodically collected from one fixed plot of C. pilosula. The 2nd instar larvae of M. hapla in soil and each morphology of nematode in root tissues were separated and counted under stereo microscope.

Results Beginning in early April, M. hapla disease of C. pilosula in Gansu Province could occur four generations per year, with average duration of 36 days, it took 28 days for minimum and 53 days for maximum to complete a generation. The temperature and precipitation had great effects on the development of M. hapla on C. pilosula. The development period was shorter under appropriate temperature of 18 ℃ and the precipitation of 141-176 mm in the field, and the average generation was about 30 days.

Conclusion This study clarifies the population dynamics and generation cycle of M. hapla in Gansu Province, which has guiding significance for the timely prevention and control of the disease.