OMAFRA: Efficacy of Wheat Fungicides

May 16, 2012

There are many different diseases which are caused by various fungal pathogens that affect cereals in Ontario and some such as the foliar diseases (powdery mildew, leaf rust, Septoria leaf spot, Septoria (Stagonospora) glume blotch and tan spot) and Fuarium Head Blight (FHB) can cause significant yield losses if not managed correctly. Although these diseases occur in all wheat producing areas of the province, their economic impact varies from year to year depending on environmental conditions. When the environmental conditions favour the development of these pathogens, local losses can be significantly greater.

The North Central Regional Committee on Management of Small Grain Diseases (NCERA-184) has developed the following information on fungicide efficacy for control of certain foliar diseases of wheat for use by the grain production industry in the U.S and Ontario. Efficacy ratings for each fungicide listed in the table were determined by field testing the materials over multiple years and locations by the members of the committee. Efficacy is based on proper application timing to achieve optimum effectiveness of the fungicide as determined by labeled instructions and overall level of disease in the field at the time of application. Differences in efficacy among fungicide products were determined by direct comparisons among products in field tests and are based on a single application of the labeled rate as listed in the table. Table includes most widely marketed products, and is not intended to be a list of all labeled products. Please refer to OMAFRA Publication 812 - Field Crop Protection Guide for a full list of available products in Ontario.

Efficacy of fungicides for wheat disease control based on appropriate application timing
Class	Active ingredient	Product	Powdery mildew	Stag- onospora leaf/glume blotch	Septoria leaf blotch	Tan spot	Stripe rust	Leaf rust	Stem rust	Head scab
Strobilurin	Pyraclostrobin 23.6%	Headline SC	G	VG	VG	E	E2	E	G	NL
Triazole	Metconazole 8.6%	Caramba 0.75 SL	VG	VG	--3	VG	E	E	E	G
	Propiconazole 41.8%	Tilt 3.6 EC4	VG	VG	VG	VG	VG	VG	VG	P
	Prothioconazole 41%	Proline 480 SC	--3	VG	VG	VG	--3	VG	VG	G
	Tebuconazole 38.7%	Folicur 3.6 F4	G	VG	VG	VG	E	E	E	F
	Prothioconazole19% Tebuconazole 19%	Prosaro 421 SC	G	VG	VG	VG	E	E	E	G
Mixed mode of action	Metconazole 7.4% Pyraclostrobin 12%	TwinLine 1.75 EC	G	VG	VG	E	E	E	VG	NL
	Propiconazole 11.7% Azoxystrobin 7.0%	Quilt 200 SC	VG	VG	VG	VG	E	E	VG	NL
	Propiconazole 11.4% Trifloxystrobin 11.4%	Stratego 250 EC	G	VG	VG	VG	VG	VG	VG	NL
	Prothioconazole 10.8% Trifloxystrobin 32.3%	Stratego YLD	G	VG	VG	VG	VG	E	VG	NL
	Tebuconazole 22.6% Trifloxystrobin 22.6%	Absolute 500 SC	G	VG	VG	VG	VG	E	VG	NL

1Efficacy categories: NL=Not Labeled and Not Recommended; P=Poor; F=Fair; G=Good; VG=Very Good; E=Excellent.
2Efficacy may be significantly reduced if solo strobilurin products are applied after stripe rust infection has occurred
3Insufficient data to make statement about efficacy of this product
4Multiple generic products containing the active ingredients propiconazole and tebuconazole may also be labeled in some states/provinces.

This information is provided only as a guide. It is the responsibility of the pesticide applicator by law to read and follow all current label directions. No endorsement is intended for products listed, nor is criticism meant for products not listed. Members or participants in the NCERA-184 committee assume no liability resulting from the use of these products.

SOurce: OMAFRA Field Crop