Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)
External Funding Partners
This project was funded in part through the Ontario Farm Innovation Program (OFIP). OFIP is funded through Growing Forward 2 (GF2), a federal-provincial-territorial initiative. The Agricultural Adaptation Council assists in the delivery of Growing Forward 2 in Ontario.
Collaborating partners in the US received funding through the North Central Soybean Research Program (NCSRP) and local State check-off boards in Iowa, Illinois, Indiana, Nebraska and Michigan.
- Determine how increasing reproduction of soybean cyst nematode (SCN) on SCN-resistant cultivars will affect sudden death syndrome (SDS) resistance performance.
- Determine if shifts in soybean production practices change the risk of SDS development, including the influence of various herbicides on SDS severity and how new products such as seed treatments and in-furrow fungicides will affect SDS under different management regimes.
- Identify where SDS is currently found in the US and Canada.
- The understanding of how changing agricultural practices, such as earlier planting, can influence disease development of SDS will enable growers to make informed management decisions in their soybean crops.
- The verification of a new experimental SDS seed treatment “ILeVO” (fluopyram, Bayer CropScience) which reduced SDS levels significantly especially early in the season when environmental conditions were more favourable for the disease will allow growers to manage SDS disease when planting soybeans early in the season.
- The validation that seed treatments can improve varietal resistance of SDS resistant varieties will allow growers to use genetics and chemical strategies in an effective integrated pest management (IPM) strategy against the SDS disease.
Sudden death syndrome (SDS) is caused by Fusarium virguilforme. The disease was first observed in Arkansas in 1971, but it has become widespread in the major soybean producing areas of the United States and was first confirmed in 1999 in Chatham, Ontario. Over the past decade SDS has become more common in the northern soybean production areas of North America and continues to move east in Ontario. SDS, unlike many other diseases, is not found often in poor yielding fields but in the “best” fields with high yield environments, such as good fertility, soil structure, etc. The foundational integrated pest management (IPM) management strategy for SDS is using resistant varieties. However, in years when environmental conditions are favorable for disease development, it is evident that genetic resistance in soybean varieties alone does not provide adequate control or reduce farmer risk sufficiently. Yield losses in Ontario associated with SDS infection can range from minimal (5%) to significant (80%).
This collaborative project was established to investigate the influence management options have on SDS development, such as planting date, seed treatments, SDS resistant varieties, environment, SCN infection, etc. Diagnosing SDS can be challenging, because other diseases and disorders cause similar symptoms to SDS. New methods were investigated to detect SDS to better identify and quantify SDS in grower fields and plants. Besides being able to identify SDS rapidly and more accurate, another deliverable from this objective is the availability of an important tool to assess soybean resistance to infection. The results over the three years have showed the yield benefit of incorporating both SDS and SCN resistance in a variety. In the Ontario locations we have consistently seen the yield benefit and would recommend producers in areas with SDS plant a variety with SDS and SCN resistance to maximize yield potential. One lesson learned is that although products registered in the US maybe promoted for control of certain diseases it is important to verify they have true efficacy and are applicable to Ontario.
Our research across multiple locations and years indicates that planting soybeans early (late April, early May) in the Midwestern US and Ontario may not always correlate to higher levels of SDS. This may be explained by our results which show that rainfall during the reproductive phase of the crop was critical to SDS foliar symptom development, regardless of soil temperature at planting. Therefore, delayed planting should not be recommended for management of SDS as it not only reduces yield potential but may not reduce SDS risk in years with substantial late season rains. Timely planting of tolerant soybean varieties combined with fluopyram seed treatment is the best management option for producers to reduce SDS risk. As a consequence of these novel results, grower recommendations will need to be updated.
Project Related Extension Publications
Scientific journal articles
Yuba R. Kandel, Kiersten A. Wise, Carl A. Bradley, Albert U. Tenuta, and Daren S. Mueller. 2016.Effect of planting date, seed treatment, and cultivar on sudden death syndrome of soybean. Plant Disease 100:1735-1743.
Yuba R. Kandel, Kiersten A. Wise, Carl A. Bradley, Martin I. Chilvers, Albert U. Tenuta, and Daren S. Mueller. 2016. Fungicide and cultivar effects on sudden death syndrome and yield of soybean. Plant Disease 100:1339-1350.