Each year, the Saskatchewan pulse and cereal commissions partner with commercial seed testing laboratories to complete an annual survey of seed-borne pathogens measured on seed grown in Saskatchewan during the previous season. All labs that offer seed testing services to Saskatchewan growers are invited to participate in the annual survey with anonymous reporting of results amalgamated by crop district from all participating labs.
Interim seed quality data, collected from the time of harvest to the end of December, are summarized and communicated to growers, agronomists, researchers, and industry during the winter months, ahead of the next crop season. These interim results provide insights into seed quality trends and identify potential hotspots for seed-borne pathogens across the province. A final summary of results, including data from seed samples analyzed after the interim results, is reported at the end of May. This final summary is submitted for publication in the Canadian Phytopathological Society Canadian Plant Disease Surveys. This publication of the provincial survey provides a record of seed-borne pathogen trends in pulse and cereal crops and allows for continued tracking of diseases over time.
The provincial seed survey would not be possible without the participation of 20/20 Seed Labs Inc., Discovery Seed Labs, Prairie Diagnostic Seed Labs, and Lendon Seeds. Thank you to all lab partners for their continued effort and support of this project. Brian Olson, independent contractor, is also gratefully acknowledged for his coordination of the seed quality survey and summarization of results. A special thanks is also extended to Dr. Randy Kutcher and Dr. Sabine Banniza from the University of Saskatchewan for their external review and pathology expertise. External review efforts of Alireza Akhavan, Provincial Plant Disease Specialist and Dale Risula, Provincial Special Crops Specialist, of the Saskatchewan Ministry of Agriculture (SMA) is also recognized with an extra note of appreciation to Alireza Akhavan and the SMA Geographic Information System (GIS) team for creating the seed-borne pathogen maps by crop district.
Pulse Pathogen Results
The interim results of commercial plate tests for seed-borne pathogens of lentil, field pea, and chickpea samples reveal a high number of pathogen-free seed samples from across the province. Results to-date suggest an overall decrease in mean severity and infection levels of seed produced during the 2021 growing season compared to results from 2020 and is among the lowest mean infection levels and highest percentage of pathogen-free samples in the past seven years.
- Greater than 96% of lentil samples were free of seed-borne pathogens; samples that did have detectable levels of Ascochyta, Anthracnose, or Botrytis had a mean infection level below 1%.
- Seed-borne Sclerotinia was not detected on any pulse samples.
- Seed-borne Botrytis was detected on less than 1% of lentil and field pea samples, but was identified on 9.7% of chickpea samples; mean infection levels were 0.5% or lower for all pulse samples.
- Seed-borne Ascochyta was detected on 25.1% of field pea samples, but mean infection levels (1.1%) were well below critical threshold levels.
- 27.1% of chickpea samples had detectable levels of seed-borne Ascochyta. On average, the level of infection was 1.3% and exceeded the critical threshold of 0.3%.
- Seedling pests such as insects and soil-borne pathogens.
Distribution of submitted samples and crop districts reporting seed- borne pathogens varies across the province. Although the maps created by the Saskatchewan Ministry of Agriculture can help identify areas of lower risk of seed-borne disease, testing of individual seed lots is still recommended.
Table 1. Average percent of pathogen-free pulse seed samples and average infection levels measured in samples with disease analyzed as of December 28, 2021.
|Crop||Number of Samples||Pathogen||Pathogen-free samples||Mean infection1|
1Mean infection level of non-pathogen free seeds
Cereal Pathogen Results
The interim results of commercial plate tests for seed-borne fusarium pathogens reveal very low mean infection levels barley, durum, oat, and wheat samples tested as of December 28, 2021. The percentages of total Fusarium spp. and F. graminearum-free samples are trending higher across all cereal samples relative to the two prior seasons.
- F. graminearum was not detected on oat samples.
- F. graminearum was detected on less than 4% of barley, and wheat samples, but was identified on 20.1% of durum samples; mean infection levels were 1.1% or lower for all cereal samples.
- The highest percentage of total Fusarium spp.-free samples were in durum (44.7%), followed closely by wheat (41.6%); durum and wheat also had the lowest mean infection levels of total Fusarium spp., 1.7% and 2.3%, respectively.
- The majority of oat samples (94.6%) had detectable levels of total Fusarium spp. with a mean infection level only slightly lower than that measured in 2020 (7.5%).
- 81.1% of barley samples reported a detectable level of total Fusarium spp.; however, the mean infection level to date is below those measured in 2020 or 2019.
Table 2. Average percent of pathogen-free cereal seed samples and average infection levels measured in samples with disease analyzed as of December 28, 2021.
|Crop||Number of Samples||Total Fusarium||Fusarium graminearum|
|Pathogen-free samples||Mean infection1||Pathogen-free samples||Mean infection1|
1Mean infection level of samples with disease
Despite overall low levels of Fusarium-infected cereal seed lots being reported in interim results, seed quality does vary by crop districts as detailed by maps created by the Saskatchewan Ministry of Agriculture and it is recommended that seed lots should be tested on an individual basis.
Published February 2022