Brief history of fusarium head blight in western Canada
The disease was first described in England, where it was called wheat scab.
Fusarium head blight in the eastern Prairies
Fusarium graminearum scab was identified in Minnesota.
Scab was common enough on wheat in Minnesota to cause concern. Fusarium graminearum had already been a problem for several years on corn in Minnesota and North Dakota.
Different varieties of wheat in Minnesota displayed different responses to Fusarium head blight - the disease had become more prevalent with the general adoption of Marquis wheat (MacInnes and Fogelman).
Fusarium graminearum was reported on corn stubble in Manitoba (Bisby and Bailey).
Of 776 Fusarium isolates collected in Manitoba, none were Fusarium graminearum (Gordon 1933).
Fusarium graminearum was isolated from 11 of 3094 Manitoba cereal samples (0.3 percent of the samples) (Gordon).
Fusarium graminearum was described as rarely isolated from cereal seeds produced in western Canada.
Fusarium head blight, called scab, already common in southern Minnesota and North Dakota, was found to have spread farther north and west (Tervet).
Fusarium graminearum was not detected in Manitoba soil samples (Gordon).
In Winnipeg, Fusarium graminearum was isolated from one out of six wheat heads with symptoms of Fusarium head blight (Gordon et al).
Fusarium graminearum heavily infected a sample of Coulter amber durum and Sinton red spring wheat from the Red River Valley of southern Manitoba (Clear and Abramson).
The first Canadian Grain Commission survey for fusarium-damaged kernels (FDK) found Fusarium graminearum in 30 wheat samples, primarily from the Red River Valley (Abramson et al). Canada Western Amber Durum (CWAD) and Canada Prairie Spring (CPS) wheats were more affected than Canadian Western Red Spring.
Fusarium graminearum was detected in 71 Manitoba wheat samples containing fusarium-damaged kernels. The situation worsened in the Red River Valley (Clear and Patrick). Canada Western Amber Durum and Canada Prairie Spring wheats were more affected than Canada Western Red Spring (CWRS).
Although Fusarium graminearum was widespread in Manitoba, Fusarium avenaceum was the most common species in samples with fusarium head blight. However, both types were found only in Canada Western Amber Durum. Fusarium graminearum was not found in the 14 Canada Western Amber Durum samples with fusarium-damaged kernels from Saskatchewan (Clear and Patrick).
High levels of fusarium-damaged kernels were found in some samples of Canada Western Red Spring wheat. Most of the damaged wheat was of the variety Roblin, which was 21.9 percent of bread wheat acreage in Manitoba in 1991.
Record rainfall across the prairies was associated with record high infection levels of Fusarium graminearum in Manitoba. Disease levels were greatest in southeastern Manitoba. Nearly half the bread wheat acreage in Manitoba had been planted to Roblin, a variety very susceptible to Fusarium head blight. High levels of infection were found in barley. Disease was also reported in oats. Fusarium graminearum was found in a few Canada Western Amber Durum samples from southeastern Saskatchewan.
Fusarium head blight was still located primarily in the Red River Valley, but was less severe than in 1993. Trace levels of Fusarium head blight were found in all Saskatchewan crop districts bordering Manitoba.
Spotty rains in Manitoba during flowering resulted in some intense localised infections. Reports of fields (at the same growth stage) only a few kilometres apart with widely different levels of infection and DON were common.
This was the third worst year for fusarium head blight in Manitoba. Southwestern Manitoba was one of the areas of highest infection. Testing carried out by the Grain Research Laboratory showed fusarium graminearum to be more common in samples from Saskatchewan this year than in previous years, especially from locations along the Manitoba-Saskatchewan border. With the exception of two samples (one from Oxbow, one from Carrot River), the levels of infection were very low, but more Saskatchewan samples were found to contain a detectable level of infection than had been found in previous surveys. fusarium head blight caused by fusarium culmorum was also more common in Saskatchewan wheat this year than in previous years. fusarium culmorum is a much less common, but still potent, DON producer.
Levels of fusarium head blight in Manitoba were very similar to those of 1996, with the southwest once again being one of the hardest hit areas and the northwest the least affected. In Saskatchewan, for the first time, fusarium graminearum was the most common cause of fusarium-damaged kernels. This shift was mostly due to an increased incidence of fusarium graminearum in the eastern part of Saskatchewan, especially the southeast. Levels of fusarium head blight outside of Manitoba continue to be very low.
In Manitoba, fusarium head blight was once again a problem, with overall severity and incidence similar to those of 1997. As in 1997, southwest and south-central Manitoba were the hardest hit areas. Northern parts were much less affected. Due to plentiful rain in June, winter wheat in Manitoba had high levels of fusarium head blight for the first time. In previous years, this crop had escaped the disease. In Saskatchewan, favourable disease weather, combined with a build-up of fusarium graminearum inoculum over the last few years, resulted in a dramatic rise in the incidence and severity of fusarium head blight in the southeast. For the first time, fusarium head blight was an important disease in this area. Since 1993, we have found an increasing incidence of fusarium graminearum in that area. This year marks the first time that fusarium graminearum was of economic importance in any area of the Canadian prairies outside of Manitoba.
Levels of fusarium head blight were lower than in 1998. Excessive spring precipitation in southwestern Manitoba and southeastern Saskatchewan resulted in many fields being left unseeded. A wide range of heading times occurred across the eastern prairies due to seeding delays in some areas. There were pockets in eastern Saskatchewan and Manitoba with high disease levels, but overall fusarium head blight levels were down from 1998
Losses to fusarium head blight were the highest to date as a result of a combination of elevated disease levels and a greater affected area. Especially hard hit were the south-central crop districts of Manitoba. Highest disease levels in Saskatchewan were in the southeast.
Once again ideal disease weather in Manitoba and southeastern Saskatchewan resulted in high levels of fusarium-damaged kernels. Especially hard hit were areas around Winnipeg, Levels in southeast Saskatchewan were the highest yet for that area, However, very dry conditions outside the southeast corner resulted in less fusarium-damaged kernels in those areas than in recent years.
Incidence of fusarium-damaged kernels in Manitoba and eastern Saskatchewan was higher than last year, but the severity was down. fusarium graminearum was once again the major cause of fusarium-damaged kernels in the wheat.
Dry growing conditions across the prairies resulted in fusarium-damaged kernels levels that were lower than they have been in this area since about 1992.
Moisture in the eastern prairies was adequate over the growing season but unusually cool temperatures appeared to suppress the disease. Although a few fields were severely affected, overall fusarium-damaged kernels levels were just above those of 2003.
Heavy rains and local flooding in May and June resulted in many Manitoba fields being drowned or unseeded. The June rains also resulted in the highest incidence of fusarium head blight in red winter wheat yet reported in western Canada. Spring wheats that were harvested frequently contained fusarium-damaged kernels, which was the primary degrading factor in Manitoba wheat in 2005.
Although there was some spring flooding in the Red River Valley of Manitoba, the growing season was characterized as hot and dry. Levels of fusarium head blight in western Canada were lower than they have been in over a decade.
Wet weather early in the summer resulted in higher fusarium-damaged kernels levels in the Manitoba winter wheat than usual, but drier weather for the flowering of spring cereals resulted in low disease levels in those crops.
Wet weather in much of Manitoba in 2008 resulted in elevated levels of fusarium-damaged kernels in both winter and spring wheats. Flooding occurred in some northern agricultural areas of Manitoba, and this caused very high rates of fusarium head blight. Approximately 50% of the wheat grown in Manitoba in 2008 was degraded due to fusarium-damaged kernels. Levels in eastern Saskatchewan were much lower, but some downgrading of wheat occurred as well.
A cool summer, with monthly temperatures averaging 2 to 3 degrees below normal, did not prevent high fusarium-damaged kernels levels in areas such as eastern Manitoba where precipitation was abundant. In western Manitoba and in eastern Saskatchewan, low levels of precipitation resulted in little fusarium-damaged kernels in the wheat.
Fusarium head blight in the western Prairies
1984, 1987, 1989-1993
Fusarium head blight caused by fusarium culmorum was found in irrigated Soft White Spring wheat (SWS) in southern Alberta. Beginning in 1989, we began to detect a few kernels of SWS infected by fusarium graminearum
Fusarium graminearum was found at a high level in a CPS wheat sample from west-central Alberta.
Fusarium head blight was found only in trace amounts in the irrigated areas of southern Alberta.
Fusarium graminearum and fusarium culmorum were detected once again in the irrigated areas of southern Alberta, but at relatively low levels. As in other years, fusarium culmorum and fusarium avenaceum were also detected in Alberta samples from a few other areas. A few wheat seeds infected by fusarium graminearum were detected around Edmonton, Alberta, and in northwestern Saskatchewan. Many reports of over-wintered grain containing pink and red kernels were received from northern Saskatchewan and Alberta during the spring of 1997. The species responsible for this discolouration in all samples submitted for testing was fusarium avenaceum. DON was not detected in these samples (detection limit of 0.5ppm).
Fusarium graminearum continued to be a rare species in Alberta and western Saskatchewan. However, it was detected in a few more locations near Edmonton, and for the first time in the Peace River area of Alberta. It was once again detected at very low levels in seed from the irrigated areas of southern Alberta.
In Alberta, levels of fusarium graminearum continue to be very low, although we did recover it from more locations and samples than in any previous year. In 1998 it was fairly common in the irrigated areas of southern Alberta, as was fusarium culmorum. This is likely due to the unusual occurrence for this area of abundant natural precipitation falling in June, giving ideal moisture conditions for fusarium head blight. In Alberta and western Saskatchewan, fusarium head blight is still a very minor disease, although fusarium graminearum infected a greater percentage of fusarium-damaged kernels than in previous years.
Dry conditions in northern Alberta and unusually cool weather in central and southern Alberta did not appear to favour the development of fusarium head blight. Once again, very few samples with fusarium-damaged kernels were received from Alberta and western Saskatchewan, and only a small number of these were infected by fusarium graminearum.
Suitable conditions for the production of fusarium-damaged kernels occurred over much of the dryland farming area of Alberta, resulting in an increased number of samples being detected with fusarium-damaged kernels. However, levels of fusarium-damaged kernels in the samples were almost always very low, and the causal species were primarily Septoria nodorum and fusarium avenaceum. Fusarium graminearum was found in only a very few fields in Alberta and western Saskatchewan. A drought in southern Alberta resulted in very few fusarium-damaged kernels being produced in that area.
A record drought affected much of the western prairies in 2001. In Alberta, 33 wheat samples with fusarium-damaged kernels caused by fusarium graminearum were found. Thirteen of these were from the Peace River area. Only a very few were from southern Alberta.
Drought affected much of the northern part of the western prairies in 2002. However, unusually wet weather in the southern areas caused a considerable increase in the number of samples with fusarium-damaged kernels and the number of fusarium-damaged kernels in the samples. This was especially true in southwest Saskatchewan and southern Alberta where most of the affected samples were CWAD. Although the levels were usually low compared to the eastern prairies, they were much above what is normally encountered. In southern Alberta, 82 of the 191 samples with fusarium-damaged kernels had fusarium graminearum as one of the causal agents. Fusarium graminearum and fusarium culmorum were the major causal agents of fusarium-damaged kernels in southern Alberta, but fusarium avenaceum and Septoria nodorum were much more important in southwestern Saskatchewan. Although unusually wet weather occurred in southern Alberta in both 1998 and 2002, fusarium graminearum fusarium-damaged kernels, as well as the level of fusarium-damaged kernels, were noticeably higher in 2002.
The western prairies were little affected by fusarium head blight in 2003. Only a few samples from southern Alberta contained fusarium-damaged kernels. In those samples, fusarium culmorum was about twice as common as fusarium graminearum.
Unusually cool growing conditions over much of the area and little history of the disease continued to keep fusarium head blight disease levels very low. Southern Alberta did see a rise in the number of samples affected by fusarium-damaged kernels. Fusarium graminearum was present in 100 of 186 samples from southern Alberta with fusarium-damaged kernels and was the dominant fusarium head blight pathogen. Although CWAD was still the wheat class most often affected, more CWRS, SWS and Hard White Spring (HWS) were affected than we have seen before.
fusarium head blight disease levels continue to be low in southern Alberta. In 2005, fusarium graminearum was found in 98 of the 190 wheat samples with fusarium-damaged kernels from CD’s 1 and 2 - a very similar number to 2004. Proportionally more SWS wheat samples (33/38) than CWAD (21/48) or CWRS (38/89) contained fusarium-damaged kernels infected by fusarium graminearum. Outside of southern Alberta, fusarium graminearum is rarely detected.
In Alberta fusarium graminearum is primarily restricted to CD’s 1 and 2. Little fusarium head blight was detected in any western CD in 2006.
In 2007, fusarium graminearum was the dominant species causing fusarium-damaged kernels in crop districts 1 and 2, infecting 14 of the 24 samples (334 of 493 fusarium-damaged kernels) from CD1 with fusarium-damaged kernels and 30 of 72 (284 of 990 ) from CD2. As usual, almost no fusarium graminearum were recovered outside of CD’s 1 and 2.
In southern Alberta, fusarium graminearum infected most of the fusarium-damaged kernels collected. As usual, outside of this area, very few fusarium-damaged kernels were found.
In southern Alberta, unusually wet weather at flowering resulted in a surprising amount of fusarium head blight in the wheat crop. Over 10% of the bread wheat and durum wheat was degraded due to the presence of fusarium-damaged kernels over the tolerance levels. These kernels were infected primarily by fusarium graminearum and fusarium culmorum. Outside of southern Alberta, very few fusarium-damaged kernels were reported.