Investigations on the Emergence of Larvae from Cysts of the Potato-root Eelworm Heterodera rostochiensis. I. Technique and Variability

Abstract

Fifteen lots of fifty individual cysts from three separate batches were exposed to the action of potato root diffusate, the hatching allowed to continue to completion and the total larvae liberated from each cyst were counted. The data obtained were analysed both as they stood and after three different transformations for variability, as well as for independence between mean and variance. Very high variability corresponding to a coefficient of variation of 1.00 was detected, and there was, moreover, a very significant correlation between mean and variance. The most suitable transformations appeared to be either logarithmic or angular—the latter being probably the more useful. The latter, moreover, tended to increase the sensitivity of analysis. The importance of residual counts when hatching is complete is emphasized even in the absence of an angular transformation of the data.