Assessing the Damage caused by Heterodera rostochiensis Woll.

Abstract

PREVIOUSLY there have been no published accounts of the effect of any species of Heterodera on the yield of the host crop under field conditions. Jones¹ attempted to obtain conditions approaching those found in the field by the use of small, artificially constructed plots or microplots. However, these were too small to give a realistic estimate of yield per acre. For insect pests differential population density-levels have been established by the use of insecticides. This is impractical, for eelworms as nematicides, in addition to affecting the eelworm population, also often exert an effect on plant growth. I have therefore investigated the effect on the yield of potatoes of differences in initial density of eelworm population. This method, possibly with some modification, should prove suitable for other Heterodera species or for any species of nematode for which reliable population estimates can be made.