Susceptibility of the Juvenile Leaves of Eucalyptus Bicostata Maiden Et Al. To Infection by Phaeoseptoria Eucalypti (Hansf.) Walker

Abstract

The removal of the waxy coating from the surfaces of juvenile leaves of Eucalyptus bicostata Maiden et al. seedlings, by wiping lightly with cotton wool, greatly increased the infection of these leaves by water-dispersed spores of Phaeoseptoria eucalypti (Hansf.) Walker. The susceptibility of the juvenile leaves of E. bicostata seedlings to Phaeoseptoria leaf spot increased with physiological age but was apparently unaffected by the age of the seedling at the time the leaf was formed. Juvenile leaves of twin cuttings of E. bicostata, grown on a high-nutrient substrate, were more susceptible to Phaeoseptoria leaf spot than comparable leaves of twin cuttings grown on a low·nutrient medium.