Colonies in culture are usually white, pale grey or pale orange, sometimes producing strong pinkish-purple pigments. Conidiomata are usually poorly developed, with few or no setae, especially in culture. Conidiogenous cells are roughly cylindrical, sometimes borne in weak clusters, and produce conidia successively from single loci. Conidia are 8-16 x 2.5-4 µm in size, fusiform, thin-walled, aseptate and hyaline. Appressoria are few in number, 6.5-11 x 4.5-7.5 µm in size, clavate to circular and light to dark brown.
Full descriptions are given by Dyko and Mordue (1979), Sutton (1980), Baxter et al. (1983) and Gunnell and Gubler (1992).
Related invasive species
- Colletotrichum acutatum
Related Farm Practice
- Light
The spread of the disease is often so rapid that by the time symptoms are noticed, the crop is in serious danger. For strawberry, fruit and occasionally petiole rots may be noticed, with sunken, water-soaked spots enlarging to cover the whole fruit within 2-3 days, with dark-brown fruit bodies producing pink spore masses. For other crops such as anemone and celery, crown rots and leaf curl may be the principal symptoms. In pine seedlings, the developing leaves around the apical bud are affected, with small, brown lesions appearing and rapidly extending. Severe stunting is eventually caused as the uninfected tissue beneath the apex continues to develop.
The species has a very wide host range, but is economically most important on strawberries.
C. acutatum can apparently affect almost any flowering plant, especially in warm temperate or tropical regions, although its host range needs further clarification. It has rarely been noted on other than agricultural or forestry land.