Differential influence of potatoes on the interaction between initial and final population levels of cyst nematodes*

The relation between initial and final soil population densities caused by two potato cyst nematode species was studied using four differential potato clones for conditions prevailing over Tamil Nadu hills.

The response curve-fits denoted that the final densities of Globodera rostochiensis stablized at high P₁ values to all of the four clones. Two kinds of patterns were discernible with G. pallida. One was that the susceptible and tolerant clones showed pattern similar to the observations made with G. rostochiensis, while the two VTn² resistant clones had a different pattern. At higher values of P₁ these two resistant clones showed stabilization around the equilibrium density line.

The study further Indicated that G. rostochiensis was mild and G. pallida was virulent under Tamil Nadu hills conditions.