The field guide to controlling needle disease
Shelterbelts, woodlots and commercial plantations throughout the country often suffer from one or more of the foliage diseases dothistroma needle blight, cyclaneusma needle blight, physiological needle blight (PNB) or red needle cast (RNC). Seasonal development of these diseases differs between diseases, locations, seasons and years with many factors contributing to outbreaks.
Control of needle disease is dependent on the correct identification of the disease. To help forest growers identify a needle disease with confidence and implement the appropriate control measures, Forest Protection Science Leader Lindsay Bulman and Technician Judy Gardner recently produced the field guide, Field assessment, control and identification of common foliage diseases of pine in New Zealand.
The field guide explains how to correctly estimate the amount of current infection in the tree crown, the number of trees that should be assessed in the stand during a ground based inspection, and how to account for the various microclimates within the stand. It also provides detailed diagnoses for each species and gives recommended control options for each disease.