Tree Disease Concepts

abiotic agent air pollution Ascomycetes ascospores aspen associated bacteria bacterium bark basidiospores beech beetles biotic blight blister rust branches brown rot cambium canker fungi caused cell wall cellulose Chapter chemical compliments of Dr conidia conifers crops decay fungi decline disease cycle disease increase Dutch elm disease effects environmental enzymes factors feeder roots FIGURE foliage diseases Fomes forest pathology fruit bodies fungicide fungus genetic growth hardwoods host hyphae infection inoculum interaction invasion lignin losses maple mellea microorganisms moisture mycoplasma mycorrhizae Nectria needle nematodes nitrogen nursery nutrients oak wilt occur organisms parasitic pathogen pathologists phloem Photograph compliments Phytopathology plantations population problems produce recognize reduced resistance result root rot sap rot fungi saprophytic seed seedlings soil species spores stain stem structures surface symptoms temperature tion tissue TREE DISEASES urban tree USDA virus viruses western white pine white pine wood decay wounds xylem