Fusarium was a prevalent disease on the Prairies last year, showing up in areas where it’s not normally seen, such as west central Saskatchewan, due to the excessive moisture in those areas.
“What’s critical now for farmers is to understand what happened on their farms,” says Mike Grenier, agronomist with the Canadian Wheat Board. “They will have some important management decisions to make now, especially in many parts of Saskatchewan.”
Saskatchewan provincial disease specialist Faye Dokken-Bouchard concurs.
“What happened with fusarium last year was a surprise to farmers, especially on the west side of the province,” she said. “The 2010 provincial cereal disease survey showed fusarium incidence up to 87 per cent in wheat and 89 per cent in durum versus 40 per cent and 50 per cent in wheat and durum respectively the year prior.”
Severity levels on average were up slightly to 1.1 per cent in wheat, and two per cent in durum versus the less than one per cent recorded since 2001.
“In 2009, the highest level of incidence was 5.5 per cent and in 2010, there was a big jump to 17.5 per cent,” said Dokken-Bouchard.
The decisions farmers need to make revolve primarily around crop rotation and variety selection.
Farmers already understand the importance of not growing back-to- back cereals in the rotation, but they also need to consider the frequency of cereals in the rotation. Fusarium does persist on crop residues, so breaks between cereals with broadleaf crops are necessary.
“What 2010 demonstrated in Saskatchewan is that there is fusarium disease innoculum throughout the province, but in most years it doesn’t present farmers any problems,” says Dokken-Bouchard.
Farmers also need to be acquainted with how other crops and what classes of wheat react to fusarium.
“Corn (in rotation), for instance, increases the risk of developing the disease as fusarium can live on corn,” says Grenier.
And not all wheats are created equal when it comes to fusarium.
“Winter wheat was severely impacted in Manitoba last year,” says Pam de Rocquigny, cereal crop specialist with Manitoba Agriculture, Food and Rural Initiatives.
“In fact, Agri-Food and Agriculture Canada recorded the second highest fusarium head blight index in winter wheat last year.”
Durum, soft white wheat, and Prairie spring red are also more susceptible than red spring. Red spring varieties exhibit a wide range of susceptibility from very poor to poor to fair to good.
“Variety selection is extremely important (to prevent or minimize the disease),” says Grenier. “If you farm at Rosetown, Sask., you should make sure you are seeding a variety with at least an intermediate rating for fusarium resistance. If you are on the eastern Prairies, you should be looking to move from fair to good ratings.”
There are now four varieties with a moderately resistant rating for fusarium resistance (see Table 1).
“Unfortunately, variety selection is not a tool in the toolbox for fusarium management (in Manitoba),” says de Rocquigny. “Farmers need
Table 1 –Varieties with the highest fusarium tolerance rating.
to look to avoidance strategies, essentially getting the crop to flowering stage to avoid infection. This translates as seeding as early as can be managed given the conditions.”
Dokken-Bouchard advises Saskatchewan farmers to use good quality, tested and treated seed.
“Seed should be tested because seed infected with fusarium will have lower germination, increased risk of seedling blight and mycotoxin development,” she says. “But farmers should know that infected seed will not necessarily lead to infections in the crop. That occurs when the fusarium head blight spores splash up off crop residue onto the growing crop.”
Dokken-Bouchard points out that the provincial survey of seeding testing laboratories showed increased levels of seed infection. The last five years has average about five per cent of seed infected. Seed from 2010 crop is showing, on average across the province, 20 per cent infection.
AndreaHildermanhashermaster’sdegree inweedscienceandisamemberofthe ManitobaInstituteofAgrologists.Shewrites fromWinnipeg,Man.
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