Alberta seed producers have done an excellent job of managing the risks associated with diseases over the years. This year conditions were perfect during flowering. A warm humid environment, and frequent periods of rainfall during flowering allows Fusaruim spp. and other pathogens to infect plants quickly. So it’s no surprise that levels of infection this fall are higher than previous years. Several of our clients have been concerned about the high incidence of disease infection in their cereals and pulse crops this year. Consequently growers are requesting more disease testing.
Seed borne pathogens can cause problems with germination, vigour and seedling health which impact stand establishment and ultimately yield.
Our numbers for Alberta samples are significantly higher than any other year that we have on record.
In Wheat for example Fusarium graminearum has spread to regions of the province where it has not been detected previously. We have completed a similar number of F. graminearum tests to date as last year and by comparison the number of positive test results has increased ten times from 3% to 30% of samples. The average infection level has double fro 0.75% to 1.5% with some samples as high as 10%.
20/20 Seed Labs Inc, conducts a Fungal screen ™ which will identify pathogenic fungi, storage molds and saprophytes. This test will report all the diseases of economic importance and allow us to provide information on choosing an effective seed treatment. Some of the more troublesome pathogens such as Septoria commonly known as glume or leaf blotch which is a seed borne disease favor the same conditions as other pathogens; we are observing as much as 17% infection. Cochliobolus sativus also known as common root rot is consistent with last year with a 1/3 of the samples being infected.
Barley samples are similarly affected, with higher infection levels than wheat other than Septoria which is typically a wheat disease. Septoria infection is at 3% versus last year’s average of 9%. Fusarium graminearum in barley has also increased with infection found in 4% of the samples tested so far this year. Cochliobolus sativus infection is at 7% which is up from an average of 2% reported last year.
We also perform a similar disease diagnostic for pulse crops, this is our Complete disease diagnostic ™again we focus on pathogenic fungi that cause diseases that are known to cause reduced seedling establishment, limit plant stands and negatively affect the quality of the crop.
The full compliment of diseases that we focus on are Ascochyta spp., Botrytis cinera., Colletotrichum spp., Fusarium spp., Scelrotina spp., and Stemphylium botryosum. These diseases have also increased over last year, and have affected seed quality both visually and physically.
Germination is affected by all of the pathogens mentioned above the Infection can cause a decline or reduction in the final germination percentage. One or two seeds can quickly spread mycelium across a germination blotter making it almost impossible to read. Often laboratories will suggest retesting in soil to get a better interpretation of the seeds planting potential or recommend a seed treatment if the seed has a good germination and vigour.
Knowledge of seed health allows producers to make decisions about using or replacing seed and use appropriate seed treatments.