PROJECT RESULTS

The Effect of a Foliar Fungicide Application on the Yield and Grain Quality of New Varieties of Wheat, Oats and Barley

Applicant: 

Ray Askin
Crop Research Organization of Portage la Prairie (C.R.O.P.)
Box 391
Portage la Prairie, Manitoba  R1N 3B7  Canada

Table of Contents:

• Background and Objectives
• Procedure and Project Activities
• Results and Discussion
• Conclusions

ARDI Project:

#98-048

Total Approved:

$4,000

Date Approved:

April 21, 1998

Project Status:

Completed May, 2001

Background and Objectives:

Manitoba farmers suffer considerable financial losses to cereal diseases every year. In 1997, wheat producers lost an estimated $56 million as calculated by Agriculture and Agri-Food Canada and Manitoba Agriculture and Food. Assuming similar losses to barley and oat production of 10%, the overall loss of cereal production in Manitoba would approximate $100 million.

Cereal production including wheat, oats and barley in 1996 in Portage la Prairie area was 263,722 acres and in the province of Manitoba was 6,799,814 acres. Total production of cereals as determined by Manitoba Agriculture Policy and Analysis Branch was 226.3 million bushels worth $1.102 billion.

Fungicide use in cereal production is not a common practice in Manitoba. Cereal market prices have caused producers to limit their inputs into the crops to minimize risk. The economics of fungicide applications to new varieties of cereals has not been adequately researched to the satisfaction of producers in central Manitoba. Registration and promotional data for some of the cereal fungicides currently on the market were generated five or more years ago on varieties no longer being grown. These varieties did not have the disease resistance packages of those currently being recommended for production. While the efficacy of the fungicides on the various leaf and head diseases is well documented, the benefits of controlling these diseases on newer, more resistant varieties is not well known.

Increasing yield by 10% through the province by using fungicides would produce an additional 22.6 million bushels of wheat, oats and barley. This would be available for the livestock, processing and export markets, aiding in the hog and cattle expansion. A result of increasing yields by 10% would be a jump of $110 million in the value of cereal production in the province or $2.6 million locally in the Portage la Prairie area.

The project provided growers with agronomic information on the disease resistance package contained in the new varieties of wheat and oats currently being recommended for production. Over the two seasons of 1998 and 1999, the CROP cereal program evaluated 17 varieties of barley, 10 varieties of hulless barley, 10 varieties of oats and 23 varieties of wheat in three-replicate tests. The test demonstrated the yield potential of each variety under naturally-occurring disease levels in each year.

Procedure and Project Activities:

In 1998, the fungicide-treated and the untreated cereal crops were established in separate tests. One test was treated with a foliar fungicide to control leaf diseases; the other test was left untreated to evaluate the tolerance or resistance of the cereal varieties to the leaf diseases. This layout was used to facilitate fungicide application to the plots and to minimize drift of the fungicide spray into the untreated plot area. In each separate test, there were 12 varieties of barley; 6 varieties of hulless barley; 18 varieties of wheat; and 9 varieties of oat. Each crop test was set with three replicates using an RCB design.

In 1999, each cereal crop was established in a split block design with three replicates, with the fungicide treatment comprising the main plot and the varieties comprising the sub-plots. The change in layout allowed for improved statistical comparison between fungicide-treated and untreated plots. In the tests, there were 9 varieties of barley; 8 varieties of hulless barley; 12 varieties of wheat; and 6 varieties of oat.

In 1998, all crop trials (treated and untreated) were seeded on May 18^th. In 1999, hulless barley, barley and oats were seeded on May 25^th, and wheat was seeded on May 29^th. Individual plots of each variety were seeded with a double-disc drill into plots measuring 1.25m x 6m. Fertilization and weed control practices followed those typically used in the production area. Tilt (propiconazole) fungicide was sprayed prior to head emergence at a rate of 0.2 L/acre in a water volume of 45 L/acre. A three-point-hitch sprayer with XR80015 flat fan nozzles was used to apply the fungicide at initiation of heading.

Leaf diseases were assessed at the flag leaf stage of each crop in the treated as well as in the untreated cultivars using a scale of 0% to 100% leaf infection. Leaf rust assessments were based on the Rust Scoring Guide, produced by the Research Institute for Plant Protection. Severity ratings were based on a scale of T (trace) to 100% infection.

The crops were harvested with a research plot combine.

Quality analysis on oat varieties were conducted by Can-Oat Milling of Portage la Prairie.

Results and Discussion:

Diseases - Leaf Rust (Puccinia spp) and Stem Rust (Puccinia spp) disease incidence were very low during both years of testing (1998 and 1999). Leaf Spotting complex (Septoria tritici blotch, Septoria avenae blotch and tanspot) disease incidence levels were higher in 1998 than in 1999. Two of the diseases, Crown Rust (Puccinia spp) in oat and Spot Blotch (Cochliobolus spp) in all the cereal crops, were present in both years. Untreated plots of wheat in 1998 had suffered leaf senescence as a result of disease by the time of rating. This made rating of the varieties not possible.

Environmental Conditions - In both years of the test, crops experienced good soil moisture conditions during May and June, followed by limited rainfall in July and August.

Barley - (Table 1 and Table 2). Yield increases as a result of the fungicide application were seen in only two barley varieties in 1998, AC Bountiful and Merit, and in three varieties in 1999, CDC Stratus, AC Queens and CDC Kendall. Thousand-kernel-weights of barley tended to be higher in the treated plots in 1998, while response was less in 1999. Disease levels were reduced as a result of the application of the fungicide. However, spot blotch, leaf rust and stem rust levels were low in the 1999 test.

Table 1. 1998 Results of Foliar Fungicide Application on New Varieties of Barley