A comparison of cereal root eelworm resistant and susceptible spring barley genotypes at two sites

Abstract

SUMMARYA comparison between otherwise identical cereal root eelworm resistant and susceptible spring barley lines was made on two sites, one lightly infested the other heavily infested with the nematode. On the lightly infested site, the grain yields of the resistant and susceptible lines did not differ, but on the heavily infested site, the resistant lines out‐yielded the susceptible lines by 20%.A similar comparison was also made between five reputedly eelworm‐resistant spring‐barley genotypes and three cultivars known to be susceptible. On the lightly infested site, the three susceptible cultivars out‐yielded all other genotypes, while on the heavily infested site they were out‐yielded by all other genotypes except one.Development of the nematode was compared in resistant and susceptible genotypes. Although the nematode was as numerous in resistant genotypes as in susceptible genotypes, either invasion or development of the nematode was retarded in resistant genotypes. Although not conclusive, there was evidence that the male was less retarded in development than the female, which was rarely found in the adult form on resistant plants.