Phytosanitary evaluation of Juglans neotropica and Quercus humboldtii in an urban woodland of Popayán-Cauca, Colombia

Abstract

Quercus humboldtii and Juglans neotropica are species native to Colombia present in the urban forests of the city of Popayán; they are of great cultural and economic importance, but they are exposed to pests and diseases which affect their health. The present study aimed to know the phytosanitary status of 73 individuals of Q. humboldtii and J. neotropica located on the University of Cauca's campus both during dry and rainy seasons. To this end, we used the method based on the six-class evaluation system of Hawksworth (1977) and we recorded 21 symptoms of which Colletotrichum sp. in Q. humboldtii and Fusarium sp. and Alternaria sp. in J. neotropica had the highest incidence and severity. Nine orders of insects were identified, the most frequent being Collembola: Poduromorpha, Diptera, and Coleoptera with 29.43%, 26.68%, and 22.44%, respectively, and to a lesser extent Lepidoptera, Ephemeroptera, Dictyoptera (Blattodea), and Tysanoptera with 4.49%, 0.25%, 0.62%, and 0.50%, respectively. Statistically, there were no differences between time and associated symptoms; nevertheless, there were significant effects of the distance between the trees and the roads regarding the phytosanitary agents present. Although there were no cases of severe diseases posing a level of damage that may threaten the survival of the trees in the short term, it is necessary to ensure their health in the future by implementing preventive and control treatments such as fertilization, pruning, and phytosanitary management.