During the period 27th Jan – 1st Feb 2014 scientists from the Rwanda Agriculture Board (RAB), wheat program and CIMMYT-Ethiopia conducted wheat rust surveys and sampling in wheat growing areas of the Northern and Southern provinces. These surveys led by Innocent Habarurema (RAB) represent one of the first attempts to understand the status and population composition of wheat rusts in Rwanda. A total of 7 unique, dispersed locations (4 research stations and 3 farmer field sites – see Rwanda Survey Mapper) were included in the survey. yellow rust and stem rust predominated; with yellow rust being recorded at all locations surveyed and stem rust recorded at all but one location. Leaf rust was not common, only recorded at one location. Disease pressure was higher on research stations vs farmer fields, especially for stem rust. Given the importance of the region for emerging new races of both stem and yellow rust, a key priority of the surveys was sampling to determine which races of rust are currently present in Rwanda. Another important reason for surveys was the spore dispersal modelling work, undertaken by Cambridge University, UK, from the recent stem rust outbreak in Ethiopia.
Model predictions of spore dispersal from the Ethiopia stem rust outbreak indicate the potential for spore movement in a south-westerly direction, with a very low probability that spores may travel as far as Rwanda. Although Rwanda is at very low risk of any spore dispersal from Ethiopia, monitoring of the rust situation in the country was considered a priority in light of this recent outbreak. A total of 14 stem rust samples (live samples plus corresponding DNA samples) and 13 yellow rust samples were collected. The samples aimed to be representative of different geographical areas and different cultivars grown. Samples are currently undergoing analysis at the Cereals Disease Lab, Minnesota, USA and the Global Rust Reference Centre, Denmark and results will be forthcoming.