Foliar Diseases
FIELD GUIDE TO INSECTS AND DISEASES OF ARIZONA AND NEW MEXICO FORESTS
Hardwood Leaf Diseases

Leaf diseases in Arizona and New Mexico are most often observed on aspen, Arizona sycamore, cottonwood and willow. Although clonal susceptibility to foliage pathogens is common for aspen and willow; whole areas can become infected during favorable moisture periods. Severe infection can cause premature defoliation and reduced tree growth.

Figure 174. Foliar diseases of aspen occur with adequate spring moisture.