Alternaria leaf spots on E. angustifolia . Lesions appear oblong, light-colored in the centre and are surrounded by dark, necrotic tissue. Alternaria leaf spot on E. angustifolia . Lesions appear oblong, light-colored in the centre and surrounded by dark, necrotic tissue. Tissue in the centre may fall out to create holes in the leaves.
Alternaria lesions cause collapse of the stem.
Centre S. Brooks, Alberta Brooks, Alberta Sheau-Fang Hwang Stan Blade Alberta Research Council Crop Diversification Centre N. Vegreville, Alberta Edmonton, Alberta Financial assistance to print this factsheet was provided by the Alberta Research Council and the Alberta Agriculture Special Crops Product Team. Literature Cited 1. Chang, K.F., R.J. Howard, and S.F. Hwang. First report of Sclerotinia sclerotiorum on coneflower. R.J. Howard, R.G. Gaudiel, and S.F. Hwang.