Fluctuaciones Anuales de la Poblacion de Radopholus Similis en la Zona Bananera de Pococi, Costa Rica


  • Q. M.F. Jimenez


Among 16 banana farms scattered throughout the Pococi area of Costa Rica 8 were selected at random to study the annual population changes of Radopholus similis. An experimental plot of hectare (2.47 acres) was established in each farm. Samples of primary and secondary roots were taken monthly during a one-year period to check population levels. Records of rainfall, sunlight, and soil temperature, provided by a meteorological station located in the center of the area, were correlated with population data. On all farms, nematode distribution levels throughout the area showed a strong common trend. Soil temperature 30 cm deep played no important role in seasonal variations. On the contrary, a close relationship between both the general nematode distribution pattern and the rainfall was found. Low peaks occurred during or after heavy rains, whereas high peaks, or initial accelerated growth, were noticed during the drier months. The average population curve indicated that because of favor