Cold Lake Operations Blueberry Study

Improved understanding of native plants can aid in establishing these species on reclaimed sites. A question regarding health and productivity of wild blueberries in the area of Marie Lake, Alberta, led to an investigation into causes of this decline, which concluded low berry yields observed in 2005 were likely a result of several natural factors including winter injury, reduced flowering, reduced pollination and a cool wet, rainy season. Decline in productivity over the past decade was attributed to increasing age of the blueberry stands (stagnation of growth) and shading from surrounding forest. No deleterious effects attributed to sulfur dioxide emissions on growth and development were observed, with low sulfur levels in the foliage and berries and no visual sulfur injury on the foliage. This project follows that 2005 study, with an examination of wild blueberry fields in Marie Lake area completed during the summer and autumn of 2009 by Dr. David Percival (wild blueberry specialist and whole plant physiologist). The parameters examined included plant morphology, nutrient status, growth, development, pest pressures and berry yield.

Upon examining five representative wild blueberry stands in the Cold Lake operating area, no deleterious effects of pest pressures or damage due to acid rain were observed. However, low berry yield potential (i.e., floral bud numbers per unit surface area) and berry number per stem values were present at most sites, and this was very apparent at the Marie Lake South and West Borque Lake sites with a high proportion of old stem growth (2+ years old). Therefore, stagnation of blueberry growth appears to be a limiting factor at the Marie Lake and West Borque Lake sites, and this is a factor contributing to the poor yields observed at these sites. However, other biotic and abiotic factors could also be negatively influencing the growth and development of the wild blueberries, such as excessively cold winter temperatures (i.e., less than -32 ºC), lack of snow cover, cool temperatures during pollination and subtle changes in rootzone microflora and microfauna. Suggested next research steps include examining soil parameters such as microbes and mycorrhizal colonization and environmental factors such as air temperature, leaf wetness, windspeed, relative humidity and snow cover.