The Ontario Corn Committee has posted the results of its study of the susceptibility of 106 hybrids to DON
Ontario farmers trying to select corn seed that will be less vulnerable to DON are being provided with a report on how well 106 hybrids performed in the 2018 crop disaster.
The Ontario Corn Committee (OCC) has posted the report on the website GoCorn.net with the caution that none of the hybrids can be considered fully “resistant.”
“Under conditions favouring Giberella, any of them can accumulate significant amounts of DON,” the committee said in announcing the results that were collected from five performance trials in Southwestern Ontario.
Shawn Winter, chair of OCC, said corn growers should use the posted information as tool to select hybrids, weighing it with the experience on their own farms and information provided by their seed dealer.
“Everybody is looking for a silver bullet. They are looking for which hybrids are going to be clean and those are the ones we want to produce,” Winter said.
The OCC said it found a wide range in the DON levels across hybrids and locations.
“The test results were subjected to extensive statistical analysis which confirmed that some hybrids differ significantly in their susceptibility to DON. Some hybrids consistently had the lowest DON levels across locations, while others were consistently among the highest,” OCC said.
The majority of hybrids fell into an average range, OCC found, with no significant difference between them.
For the study OCC collected 1,255 grain corn samples from 82 hybrids at Belmont, Exeter and Ilderton and 54 hybrids at Ridgetown and Tilbury.
The hybrids all silked between late July and the first week of August when frequent rains and high humidity created favourable conditions for Gibberella ear rot infection and DON accumulation.
The results of the tests are displayed using a colour coding system ranging from green to red.
The lower the tendency for a hybrid to accumulate Don the greener the colour. Hybrids with a yellow code tested in the middle of the range, while hybrids coded orange or red were the most susceptible.
Winter said one way farmers can spread their risk of DON accumulation is to spread out the flowering dates of their corn crops.
Inoculation of the corn with Gibberella spores happens three to four days after flowering. After that period, the risk drops.
“If you have frequent rains in that three to four day period, your risk escalates. If you can spread out your flowering dates, that reduces the risk a lot,” he said.
OCC also announced it will conduct inoculated trials in 2019 at Ridgetown and Ottawa to gauge DON susceptibility of hybrids.
The committee said inoculated trials will ensure all hybrids are selected to the same level and types of disease pressure in years when there is little natural infections.
OCC is comprised of representatives from the Ontario Ministry of Agriculture, Food and Rural Affairs, Agriculture and Agri-Food Canada, University of Guelph, Grain Farmers of Ontario, the Ontario Soil and Crop Improvement Association and the Canadian Seed Trade Association.