Scleroderris Canker Survey Using Aerial Photography

Abstract

Study plots with known infection levels of Scleroderris canker were interpreted on aerial 70 mm normal color and color infrared photographic transparencies. In the interpretation procedure, five infection levels, the identifying characteristics of Scleroderris canker, and the relationships between these identifying characteristics and the infection levels of the stand were defined. The defined relationships were used to develop photointerpretation keys which were evaluated on aerial photographs of test stands by personnel likely to use the keys in practice.

The evaluation results showed Scleroderris canker was detectable and classifiable into five infection classes to an acceptable degree of accuracy. Detection accuracies in excess of 90% and classification accuracies greater than 80% were obtained with the inexperienced personnel. It was concluded that photointerpretation can improve the present survey techniques by helping to make more efficient use of field personnel and time.