Project Details - Full Facts for Selected Year
Information and Results
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Sudden death syndrome (SDS) is an economically important fungal disease of soybean that is widely distributed across the soybean growing regions in the United States and is spreading throughout the Midwest. In Kansas, yearly estimates provided by Extension Row Crops Pathology range from trace levels to 250,000 bu of yield loss. However, SDS has been a perennial cause of yield loss in irrigated soybean production in the Kansas River Valley and reported statewide numbers may be an underestimation of the impact that this disease can have in certain locations. Observations of plants infected during early pod development have often resulted in no pods visible at maturity. Yield losses of up to 100% have been attributed to the disease, with losses between 5 to 15% more common in affected fields.
1. Determine the amounts and intervals of sprinkler irrigation treatments associated with the onset, development, and severity of sudden death syndrome (SDS).
2. Determine if soil oxygen content influences SDS disease development and severity.
3. Determine if either irrigation treatment or soil oxygen content, or both, influence soil populations of the SDS pathogen (Fusarium virguliforme).
Progress of Work
Final Project Results
Irrigation regimes influenced pathogen populations in the soil. Low-level irrigations at R1 reduced F. virguiliforme pathogen populations in the soil when measured at mid-season compared to those at planting. Thus, there appears to be a negative relationship between disease severity and pathogen populations as influenced by irrigation. It is clear that there is a positive relationship between soil oxygen content and SDS disease severity, however there is no significant relationship between soil oxygen content and F. virguiliforme populations in the soil. Thus, this suggests that aerobic (higher oxygen) soils facilitate the SDS disease development process, as opposed to anaerobic (low oxygen) soils. So far, the data shows that irrigation treatments have an impact on soil pathogen populations as mentioned above. In general, it appears that low-level irrigations at R1 reduce F. virguliforme populations the most, however, after combining 2013 and 2014 data, the lowest disease severity was observed when low-level irrigations were conducted at V4 and high-level irrigations were conducted at R1.
Benefit to Soybean Farmers