Spotlight on Research: Balancing Seed and Foliar Fungicide Treatments
As many producers have moved to an alternating canola-cereal rotation, and producers cultivating on-farm cattle feed grow continuous barley, the risk of above- and below-ground plant diseases increases, according to Kelly Turkington, research scientist, plant pathology, Agriculture and Agri-Food Canada (AAFC) Lacombe Research Centre. “Given that we don’t have varieties with resistance to all leaf disease issues, producers have increasingly relied on fungicide application,” he explained. As a result, producers and crop consultants will need information on disease resistance levels in various barley varieties, as some may not require fungicide treatment.
Early-season application of fungicide with herbicide is popularly believed to suppress cereal leaf diseases later in the season. However, studies done by Turkington and his research collaborators suggest the practice may offer limited benefit. A new study being conducted by Turkington and his colleagues has found that systemic seed treatments may provide some early-season suppression of leaf disease in barley, negating the need for broad-scale application of foliar fungicide with herbicide at a plant-growth stage when its impact is relatively minimal.
In previous work, Turkington’s team also found fungicide application at the flag leaf stage can improve malting barley productivity and kernel characteristics. However, Turkington said little is known about fungicide application at the flag and head-emergence stages and its interaction with seed treatments and plant growth regulators (PGRs), which may reduce lodging by shortening plant height.
Samples of the barley variety “Sundre” was exposed to net-form net blotch at a trial in Melfort, SK in 2013.
This is the starting point for the research project that Turkington is leading: “The impact of seed treatments and foliar fungicides and their interaction with variety resistance and plant growth regulators on barley productivity and quality.” Alberta Barley is providing $57,995 in funding support for the project, which started in 2013 and runs to 2018.
The project involves AAFC technical and scientific staff from Alberta, Saskatchewan, Manitoba and Prince Edward Island as well as staff from the Canadian Grain Commission. Their collaboration on this project will facilitate future research opportunities on a national scale.
The project’s initial field trial involving a common malt barley variety (such as AC Metcalfe) will determine the interactive effects of seed treatment, PGR application and fungicide application at both stages on leaf disease severity, malting barley quality, yield, microbial load and mycotoxin level. The second phase of the project will investigate the interaction of seed treatment, fungicide application and level of disease resistance on disease development in barley.
“There may be the possibility to use seed treatments to delay early and mid-season disease development so that an in-crop fungicide only needs to be applied once at the head-emergence timing,” said Turkington. “Research will also help to determine the optimum timing of foliar fungicide and how these in-crop treatments interact with seed treatments and PGRs in terms of disease management and crop productivity, quality and mycotoxin contamination.” The benefit to producers may be a combination of a reduction in both disease risk and input costs, while identifying strategies that limit crop lodging and/or mycotoxin contamination.