Download or read book An Illustrated Guide to the State of Health of Trees written by E. R. Boa and published by Food & Agriculture Org.. This book was released on 2003 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effective management of tree health problems depends on early detection and recognition of symptoms. This guide includes 140 photographs of symptoms from more than 50 tree species, which can be used as a basis for demonstrating the effects of pest (biotic) and non-living (abiotic) influences on trees. It is not designed as an identification guide to insect pests and diseases of trees, but rather seeks to enable a preliminary diagnosis and assessment of potential problems, in order to promote better planning and more effective management of forests and trees.