Improve Sudden Death Syndrome Identification and Management
Soybean leaves often show SDS symptoms after flowering.
Thanks to cool, wet conditions that affected planting during the 2019 season, soybean fields are now more susceptible to a disease that causes U.S. growers to lose millions of bushels each year.
Reports of Sudden Death Syndrome (SDS) are coming in across the soybean belt with confirmed sightings in ND, NE, KS and NC. If you’ve had SDS in your fields before or are in an area near recent confirmations, scouting now for the disease can help you plan accordingly and better prepare you for the 2020 season.
The fungus Fusarium virguliforme overwinters in the soil and infects soybean roots at the start of the growing season. Cool, wet conditions like we endured this season are ideal for SDS to affect a large percentage of planted acres. Irrigated fields and those with low nutrient densities, low pH or moderate to severe soil compaction are at a higher risk of infection.
During the reproductive growth stages, SDS symptoms will be visible as pale green and yellow spots on the leaves. Eventually, these spots may grow and turn brown, and leaves may die and prematurely fall from the plant, while petioles remain attached to the stem. Pods and seeds may also be aborted.
These foliar symptoms can be indicators of SDS, but studying the roots can be a stronger indicator of the disease. If SDS is present in your soybeans, you can pull diseased plants out of the ground and see a decayed tap root and lateral roots. If you were to cut the tap root lengthwise, you would see a gray to reddish brown color, and not a healthy white.
A Different Management Plan for 2020
Soil management techniques, including minimal soil movement and compaction, as well as improved soil drainage can help slow SDS movement and alleviate symptom severity. When coupled with crop rotation and planting SDS-resistant and/or SCN-resistant varieties, these practices can help prevent SDS from drastically impacting your crop.
Investments in SDS-resistant varieties are best supported by seed treatments that protect your soybeans. Until recently, there have been limited options to combat SDS. Upon Environmental Protection Agency (EPA) registration, Adepidyn® fungicide will be marketed as Saltro® fungicide seed treatment, which protects against SDS without adding above or below ground stress to the plant. After 3 years of trials, soybeans under high SDS pressure treated with CruiserMaxx® Vibrance® + Adepidyn yielded a statistically significant 3 bu/A more than soybeans treated with CruiserMaxx Vibrance paired with competitors. In a low pressure environment, Adepidyn-treated soybeans yielded 1.8 bu/A higher. Learn more about this new SDS treatment for the 2020 season.
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Adepidyn/Saltro is not currently registered for sale or use as a seed treatment in the United States and is not being offered for sale.