This is the report from a BSPP Junior Fellowship.
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Papua New Guinea (PNG) is known as the “Land of Unexpected”. Perfect destination for a PhD.
PNG has the world’s richest island flora and 85% of the population depends entirely on small-scale, swidden agriculture. The country has the fourth most under 5-year-old stunted children in the world, and the main staple crop is the sweet potato (kaukau). There are over 1,000 clans and 800 languages in PNG, making it an extremely diverse country in culture. Whilst farmers in PNG often rotate their crops, few practice disease or pest management. Agricultural extension is very limited in the country.
Thanks to the BSPP Junior Fellowship, I worked together with researchers at New Guinea Binatang Research Centre (BRC) and farmers along the Mt Wilhelm altitudinal transect (175-3,400 m) in March 2022. With this grant, I trained local researchers in the basics of plant disease diagnosis and isolation. I have been trained in plant pathology in the UK and US, and visited CABI’s Plantwise program in Nepal and Costa Rica previously.
My host institute mostly specialises in ecological research and whilst researchers have been noticing plant diseases, they have never carried out any isolations before. I took all the lab consumables (e.g., water and potato dextrose agar plates, forceps, Bunsen burner adapter for gas cartridge, Agdia ImmunoStrips for rapid diagnostics) along with a few books of the Diseases and Pests Compendium Series to PNG. To avoid being a “parachute scientist”, I also took all the equipment and kits for soil DNA extractions. As international researchers tended to ship out all their samples out of PNG for analyses, I was adamant to do almost all analyses within the country.
After a quick workshop on plant pathogens at the main research station in Madang, we set off to Mt Wilhelm (approx. 4,500 m) for a scoping trip. BRC established a unique altitudinal transect along the mountain that consisted of 6-8 villages. My expedition’s aims were to identify crop diseases, estimate community plant pathogen load, investigate the role of on-farm crop diversity and explore farmers’ attitudes towards crop management. Previously, our lab found that 92 plant species were grown along the transect and insect herbivory damage peaked at 700 m.
I spent two weeks along this transect and descended from 3,200 m to 700 m. Some of the main damages we found were caused by sweet potato weeevils, leaf spots, bacterial and fungal wilts. The number of crops within one garden greatly varied from 2-4 to 8-14. Farmers were all interested in diagnosing the problems and were open to management recommendations. I planned to carry out some isolations back in Madang and come back for a longer expedition along Mt Wilhelm to measure the community plant pathogen load and produce flyers on different diseases and their management in Tok Pisin.
Unfortunately, the “Land of Unexpected” lived up to its name, and I became sick as we were descending from 1,400 m. The local community said that my sickness was caused by forest spirits that went into my stomach because I ate lots of bananas and kaukau-s. Whilst the village leader tried to get the spirits out of my stomach by wrapping a burnt banana leaf around me and making a popping sound, I was diagnosed with malaria back in Madang.
PNG’s population is distributed sparsely in the lowlands due to the prevalence of malaria. It is a common disease and doctors are used to treating it. However, my prophylaxis and intensive treatment regiment failed after a week. Having made friends at the clinics, I even got to see my own parasites in my red blood cells underneath a microscope. As my condition was declining, my insurance provider decided to fly me out to Australia where I was hospitalised. It is likely that I was infected with a drug-resistant strain that was harder to clear out.
I am putting my PhD on hold for now, but it has been quite an adventure. Overall, the quick demonstrations and training were a great success. I cannot thank enough BSPP’s kind support and whilst PNG is a tricky country to work in, it is teeming with exciting plant pathogens that are waiting to be discovered!
University of Southampton
Caption: DIY plant pathogen isolation in Papua New Guinea. Diseased material was cut up and soaked three times in 30% bleach before plating it on WA and PDA plates. After a few days of incubation, the colonies were further isolated on individual plates.