PATHOLOGICAL PROBLEMS ASSOCIATED WITH PROPAGATION MATERIAL IN PROTEA NURSERIES IN SOUTH AFRICA

Preliminary surveys were made of indigenous Proteaceae in nurseries and botanic gardens in the South-western Cape to determine to what extent pathological problems are associated with propagation material.
Diseased material collected from nursery beds and mistbeds indicate that the most significant local nursery diseases are caused by soil and seed-borne fungi.
Monitoring of seed, seedling and cutting diseases has shown that pre- and post-emergence damping-off and seedling blights, are the most prevalent in nursery beds, particularly on the genus Protea.
Dieback of cuttings in mistbeds, caused by a range of organisms including Colletotrichum gloeosporioides is widespread, and species of Leucospermum, Leucadendron, Serruria and Protea are susceptible to cutting dieback.
Organisms frequently isolated from all sources of propagation material included Fusarium spp.; Rhizoctonia solani; Phytophthora cinnamomi and Botryosphaeria spp.
Provisional control recommendations are given for specific propagation diseases.
Seed treatments found to be effective in controlling damping-off diseases are also discussed.

I International Protea Research Symposium

L.M. Benic

https://doi.org/10.17660/ActaHortic.1986.185.24