By Treena Hein
September 2, 2014 - Many Ontario wheat farmers already know about recent research showing increased wheat yield resulting from the combined use of fungicides and nitrogen, but more results are now available.
“Previous research had focused on soft winter wheat,” says Peter Johnson, provincial cereal specialist with the Ontario Ministry of Agriculture and Food and Ministry of Rural Affairs (OMAF and MRA). “It was unknown if hard red winter wheat (HRW), which is generally lower-yielding but higher in protein, will respond in the same manner.”
To find out, Johnson and his colleagues conducted trials from 2011 to 2013 to determine the yield, protein potential and economics of growing HRW under a nitrogen-by-fungicide management regime. The team included Ontario Soil and Crop Improvement Association staff Shane McClure (technician), Marian Desjardine (administrator), and Ken Janovicek (statistician), as well as OMAF summer assistants. Financial support was provided by Agriculture and Agri-Food Canada through the CanAdvance and Farm Innovation Programs, Grain Farmers of Ontario, many provincial soil and crop improvement associations and private companies.
Seven sites across southwestern Ontario were used in 2011, with six in 2012 and five in 2013. There were four treatments in the study: 90 lbs N with no fungicide, 90 lbs N with two fungicides, 150 lbs N with two fungicides and 180 lbs N with two fungicides. In 2012 and 2014, 120 lbs N treatments were added or replaced the 90 lbs N treatments to better represent grower practices. The first fungicide was applied at weed control timing (T1) and the second fungicide was applied at anthesis (T3, two to five days after heading). A plant growth regulator was applied at six sites to prevent lodging. “We took leaf disease ratings at both T1 and T3, head disease ratings at late grain fill, and lodging score prior to harvest,” Johnson explains. “At harvest, we measured yield, moisture, test weight, thousand kernel weights, lodging and protein.”
It turned out that almost 80 per cent of trial locations had a profitable yield response from applying fungicide, replicating previous soft wheat study results. “That’s without considering the benefit of
Fusarium protection and potential quality impacts,” Johnson explains. “The yield data from 2013 shows just how massive yield response to fungicide can be in a year with high Fusarium pressure. Three of the four sites that year (the fifth site had no treatment without fungicide) had a yield response of over 13 bu/ac.”
The average bushel advantage of fungicide use over the entire study was 8.3 bu/ac. “The cost of applying two fungicides is approximately $30 per acre,” Johnson notes. “At a HRW price of $7 per bushel, only a 4.3 bu/ac gain is required to cover costs.”
With regard to N cost return, the addition of 60 units of N (150 lbs instead of 90 lbs) coupled with fungicide increased yields 5.2 bu/ac, and if N costs $0.49/lb ($500/t urea), that’s an additional cost of $29.58 per acre for an additional 60 lbs N. “Current wheat prices require 4.9 bushels to pay for this extra N,” Johnson explains. “But this calculation ignores the impact of increased protein levels, and that the yield response from increased N was variable across locations. The average outcome is break-even solely from a yield perspective, but is better in some locations.”
Almost all sites had an economic advantage when N was increased from 120 lbs to 150 lbs with fungicide applied. There was little benefit found in increasing N from 150 lbs to 180 lbs. “We achieved maximum economic yield at 150 lbs N, requiring only 2.4 bu/ac to cover the added cost,” Johnson notes. “Most sites had an increased economic return with 150 lbs N, while the remainder broke even.”
In Johnson’s view, the most important impact of this trial could well be the increase in protein levels. A limited data set from the study shows that HRW approaches maximum yield with 150 lbs N, but protein levels continue to rise with N applied above that rate. An additional 60 lbs N/ac to 180 lbs N increased protein level by a full one per cent over the 120 N plus fungicide treatment on average (variable across locations). Protein levels increased 0.6 per cent from 120 lbs N to 150 lbs N, again making 150 lbs N appear to be the “sweet spot.”
The economics of this increased protein can significantly change the profitability picture, Johnson points out. “Using average protein values from the trials, 120 lbs N would not achieve any protein premium.
At 11 per cent protein, many purchasers add an additional $5/t price premium (with an extra $15/t for greater than 12 per cent protein). Using this value would add another $20 per acre income from the additional N. As increased yield was at the break-even level, this protein premium would be all profit, making the increased management inputs significantly more viable. About two-thirds of the locations had an economic advantage by increasing from 120 lbs N to 180 lbs N when additional revenue from both yield and protein are considered.”
Johnson encourages growers who have not had lodging concerns in the past to try increasing N on HRW to 150 lbs/ac on a couple of strips to see what the response will be on their farms. “Standability has been extremely good at almost all locations considering that the majority of the sites did not use a growth regulator,” he says, “but just remember to always use caution when increasing N rate.”
This year, Johnson and the team are studying split nitrogen applications on HRW in conjunction with Dr. David Hooker and the team from the University of Guelph’s Ridgetown Campus. The hope is that split applications will have even more protein boost for HRW, he says – the “Achilles heel” of this crop over the last few years.