Published online by Cambridge University Press: 06 April 2009
An account is given of an investigation of the causes of error in estimating virus concentrations by the local lesion method. The irregularities were found to be due to:
(1) Variations in the response of (a) whole plants; (b) individual leaves.
(2) Variations in the volume of liquid used.
(3) Variations in the probability of the production of local lesions.
(4) Variations in the percentage of leaf hairs broken during the inoculation process.
An apparatus is described, the use of which reduces these irregularities to a minimum.