Multiplication of Several Meloidogyne Species (Nematoda) On Cultivated Asparagus

Two month-old asparagus seedlings (Asparagus officinalis L.) of four cultivars were each inoculated with 1,000 J2 of different populations of Meloidogyne species: M. incognita (three non-virulent populations and one virulent Valbonne population carrying the Mi gene for virulence to tomato), two M. javanica populations, and one population each of M. arenaria and M. hapla. A susceptible tomato cv. St. Pierre and an Mi gene resistant tomato cv. Piersol, inoculated at the 2-leaf stage with 300 J2, served as standards for comparison. After 2 months, the few galls that formed on asparagus ranged in diameter from 1 to 3 mm and usually arrested root growth. There were no significant differences in crown weights of asparagus between those inoculated and uninoculated controls. Final nematode numbers per plant reached a maximum of 41 (adult females) comprising 47% of all life stages. Meloidogyne incognita had most nematodes in root and soil, M. hapla the fewest and M. javanica and M. arenaria were intermediate. Few males were observed in roots and none in soil. Sex ratios were less than 0.08 (except for M. arenaria which reached 0.35). No population x cultivar interaction was observed. Linear correlations were significant (p=0.05) between damage on susceptible tomato, as measured by numbers of healthy leaves, and numbers of females on asparagus roots for all populations except the virulent Valbonne.