Some Aspects of Avocado Propagation and Diseases Associated with Nursery Seedlings in Barbados

Propagation of avocado seedlings was started on a large scale at Soil Conservation, Haggatts in 1971. Propagation is done either by budding or grafting on to seedling rootstocks. Grafting and budding is normally done between December and April. Shield budding is done when the rootstock is red-brown in colour and still undergoing active growth from the seed. Once the seedlings have become green in colour and have 'hardened off' grafting is the method adopted. No grafting is done during the hot summer months: the rootstocks at rhis time have developed a white, corky and brittle pith and the percentage take is quite low. Seeds are sown directly into polythene bags: rhus reducing transplanting to a minimum. All seeds are hot water treated and the soil fumigated with methyl bromide, before being sown. Nursery seedlings are affected by root rot caused by Phytopothora cinnamomi, and by collar and fruit rot fungii. Further work is being done ori collar rot — Botoyodiplodia theobrornae — and fruit rot Phomopsis sp.