Cause The fungus Colletotrichum gloeosporioides (sexual: Glomerella cingulata) has been found a few times by the OSU Plant Clinic. Warm temperatures and stressed or weakened plants favor this fungus. Rain splashes spores onto weakened or damaged tissue. European privet is highly susceptible; Ligustrum amurense (Amur), L. ovalifolium (California), L. ibota (Ibota), and L. obtusifolium var. regelianum (Regal) privets are fairly resistant.
Symptoms Leaf spots that develop along the margin often are associated with wounds. Spots are round to oval and have tan centers with scattered dark fruiting bodies (acervuli). A pinkish white spore mass may be evident in the spot in moist weather. The fungus also can invade branch or twig stubs and form a canker. Cankers may be dotted with pink pustules (acervuli). Cankers on the sides of stems continue to expand and can girdle the stem. All the leaves from that point on up dry and may continue to cling to the stem.
Cultural control
- Remove and destroy diseased branches and twigs.
- Propagate from pathogen-free stock plants.
- Minimize wounding especially when new growth is present.
Chemical control Apply at shoot emergence.
- Armada 50 WDG at 3 to 9 oz/100 gal water. Do not use a silicone-based surfactant. Not for nursery or greenhouse use. Group 3 + 11 fungicide. 12-hr reentry.
- Bonide Fung-onil Multi-purpose Fungicide at 2.25 teaspoons/gal water. Group M5 fungicide. H
- Compass 50 WDG at 2 to 4 oz/100 gal water. Do not use organosilicate additives. Group 11 fungicide. 12-hr reentry.
- Daconil Weather Stik at 1.38 pints/100 gal water. Group M5 fungicide. 12-hr reentry.
- Eagle 20 EW at 6 to 12 fl oz/100 gal water. Group 3 fungicide. 24-hr reentry.
- Heritage at 1 to 4 oz/100 gal water plus a non-silicone-based wetter sticker. Group 11 fungicide. 4-hr reentry.
- Mancozeb-based products. Group M3 fungicides. 24-hr reentry.
- Fore 80 WP at 1.5 lb/100 gal water plus a spreader-sticker.
- Protect DF at 1 to 2 lb/ 100 gal water plus 2 to 4 oz spreader-sticker.
- Myclobutanil 20 EW T&O at 6 to 12 fl oz/100 gal water plus spreading agent. May observe a PGR effect. Group 3 fungicide. 24-hr reentry.
- Spectracide Immunox Multi-Purpose Fungicide Spray Concentrate for Gardens at 1 fl oz/gal water. Group 3 fungicide. H
- Spectro 90 WDG at 1 to 2 lb/100 gal water. Group 1 + M5 fungicide. 12-hr reentry.
Reference Mix, A.J. 1925. Anthracnose of European privet. Phytopathology 15:261-272.