BSPP News Spring 2001 - Online Edition

The Newsletter of the British Society for Plant Pathology
Number 38, Spring 2001 

Conference and Travel Reports

Pathology in Costa Rica

Following on from the ISPBB meeting in Prince Edward Island it seemed sage to call in to Costa Rica where it is considerably warmer and less flat. An eventual vacation was in mind, but first I spent three days at CATIE (Tropical Research and Higher Education Centre-"an international, non-profit civil association….with emphasis on Ceentral America and the Cribbean") near Turrialba about 3 hours from the capital San Jose.

Admin building at CATIE; author in ornithological mode

The facilities are in a beautiful campus surrounded by hills, with an impressive lake and a white water river on one boundary. Their research objectives centre on sustainable production, environmental protection, food security and rural poverty. These umbrella terms incorporate such issues as collection and introduction of germplasm of crop and forest species, integrated pest management and agroforestry systems. There I met the pathologists and biotechnologists and presented a seminar on our research spanning about 16 years on resistance to vascular pathogens of Theobroma cacao (Verticillium dahliae), cassava (Xanthomonas axopogonis pv manihotis) and oil palm (Fusarium oxysporum f.sp. elaeidis).

Vera Sanchez did a split PhD with Richard Shattock at Bangor (he is a regular visitor here, understandably) and she is still tackling late blight, but on tomatoes. There appears no effective resistance in the large tomato types favoured in Costa Rica and chemical control measures are uneconomic or environmentally not favoured. Sadly, biological control with antagonistic fungi has had very limited success. An interesting alternative strategy is via womens' groups to extol the virtues of genotypes with some resistance but with very different phenotype such as cherry tomatoes. It is though, a conservative market in Costa Rica and it could be a long road to convince the public to eat fruit which "resembles its wild relative". Also she is tackling the leaf spot of coffee caused by Mycenae, a basidiomycete which forms remarkable infective "heads" from aerial mycelium. A plant clinic is also in operation in her section.

Ulrike  Krauss did her PhD with Jim Deacon on groundnuts (in Edinburgh?!). She is now funded by CABI working on biological control of cocoa diseases (initially in Peru- the tale of her rapid, enforced exit is worth hearing!) . She is endeavouring to achieve some control, using Trichoderma and Gliocladium, of the devastating Moniliophthora pod rot ("frosty pod") which has led to the abandonment of much of the mature cocoa in the south east coastal lowlands. I visited that area and witnessed the large areas that were once plantations returning to forest.

Abandoned cocoa plantation in Caribbean coastal lowlands; Moniliophthora rampant.

All very beautiful, but sadly the local economy has had to switch to tourism. Her work is mainly based at eleven trial sites in Costa Rica and adjoining Panama, including  indigenous Indian (for example Bribri) Reserves. The antagonistic fungi are grown on rice at CATIE, transported in cool boxes for the 7 or 8 hour journey to the coast, a few rivers are crossed (not trivial as I experienced in the wet season) then the conidia and rice are separated through ladies' hosiery (removed first) with river water before spray application to the cocoa pods (again, problematic in the wet season). In Peru losses were reduced from 78% (when cultural control was practised by physical removal of infected pods) to 36% in plots treated with antagonists. Biocontrol may assist in rehabilitation of coca smallholdings surrounded by abandoned fields which serve as a source of inoculum. There is a growing export market for certified organic cocoa (and coffee).

Organic coffee at CATIE.

With the excellent guidance of Dr Carlos Astorga head of biotechnology, I visited the extensive collections of accessions of Central American crop spp such as cocoa, coffee, fish palm (source of palmeto or palm hearts), Passiflora, cassava also African oil palm and many tree fruits surely just waiting for better marketing. These exotics can be bought by the roadside but are not common in larger supermarkets. Europe awaits…. The large scale, in vitro propagation of coffee plantlets from embryogenic suspensions was impressive.

CATIE runs various MSc and PhD programmes such as in agroforestry and in ecological agriculture but there is no masters course yet in plant pathology. They have established relatively recently split PhD programmes with Universities including Wales at Bangor.

With the much needed help of a 4WD we moved on. I won't describe the magnificent forests, volcanoes, beaches or the remarkably diverse flora and fauna because you might get the impression that I lost my pathology hat en route. Ask me sometime about how we rescued a two-toed sloth.

Thanks to all at CATIE for their hospitality and a fascinating visit. Hasta luego!

Richard M. Cooper
University of Bath