Effect of pot volume on root growth, Radopholus similis reproductive potential and its damage on bananas

The migratory endoparasite Radopholus similis is the most damaging nematode attacking bananas in Costa Rica. Infected plants have poor root anchorage and the ability of the root system to take up water and nutrients is reduced, which results in decreased bunch weight and longevity, and increased plant vegetative cycle. In the last 25 years, bananas with different degrees of susceptibility to nematodes have been identified (Stoffelen et al. 2000, Stoffelen et al. 1999a, Stoffelen et al. 1999b). Susceptibility is measured by considering variables such as: the number of nematodes, their reproductive index, root necrosis and damage, and fresh root and foliage weight. Although guidelines exist to screen Musa germplasm for resistance and tolerance to nematodes (Speijer and De Waele 1997, Sarah 1996) the effect on the end result of the specific steps used has not been considered. For example, pot volume could influence the reproductive potential of the nematodes and other variables. When it is mentioned, pot volume does vary, from 0.4 L to 10 L in Fallas and Marban 1994, Fallas et al. 1995, Fogain 1996, Fogain et al. 1996, Fogain and Gowen 1998, Gonzalez et al. 1997, Marin et al. 1999, Marin et al. 1998, Mateille 1992, Mateille 1993, Mateille 1994 and Sarah et al. 1993. Pinochet (1979) used 30 L-pots. The present study was set up to determine the influence of pot volume on R. similis population growth, its damage and reproductive index, and root growth as a function of root thickness in cv ‘Grand naine’ (Musa AAA).