Content by Connie Tande

Early Yellowing in a Soybean Field May Indicate Presence of the Soybean Cyst Nematode
Some portions of soybean fields may show clusters of plants yellowing while the rest of the field is still green. One of the factors that could lead to soybean plants showing early yellowing in clusters is soybean cyst nematode (SCN).

Sudden Death Syndrome Starting to Develop in Soybeans
Sudden death syndrome of soybean is starting to develop in soybean fields in South Dakota. Fields currently being found with sudden death syndrome have symptomatic plants scattered within the field, but continued disease development may lead to larger clusters of infected plants.

Goss’s Bacterial Blight Beginning to Show Up in Corn
Goss’s bacterial blight was found in a few corn fields scouted the week of August 5, 2019. The severity ranged from low to moderate, where at least 25 percent of the leaf area was killed by the bacteria infection on several plants. The disease is characterized by long, tan-gray lesions with wavy margins found in the center of the leaf or along the edges of the corn leaf blade.

Holcus Spot or Plant Injury?
Is your corn developing spots? Corn fields have been found with what appears to be Holcus spot, a bacterial disease. Upon further investigations, the leaves were found to be negative for any plant pathogens.

Frogeye Leaf Spot of Soybean
This fact sheet is about a soybean disease that is increasingly becoming more severe in South Dakota. Moreover, fungicide resistance for this pathogen has been detected in South Dakota.

Winter Wheat Disease Update: Wheat Streak Mosaic and Tan Spot Developing at Low Level
Winter wheat fields scouted the week of May 27, 2019 in South Central South Dakota were found with wheat streak mosaic virus and tan spot developing at very low levels. Both diseases were found in non-rotated wheat fields.

Test Your Soil for the Soybean Cyst Nematode (SCN) This Spring
The soybean cyst nematode (SCN) is a major soybean pathogen that causes significant yield loss. Fields that were not tested for SCN last year can still be sampled this spring to determine the presence of SCN or SCN population changes if testing was done in the past.

2018 Field Plot Summaries for Wheat Disease Management Trials
The wheat disease management field experiments conducted in the 2018 growing season evaluated several experimental and commercially available fungicides for managing foliar, head or root diseases of spring wheat. Foliar and spike/head diseases incidence and severity were assessed. The field experiments were implemented at Volga Research Farm and Northeast Research Farm (NERF) near South Shore, SD. Results of the same experiment may vary between Volga and Northeast due to environmental differences between the two locations.

2018 Field Plot Summaries for Soybeans: Plant Disease and Fungicide Trials
This is a summary of soybean field research studies that were conducted in 2018. The purpose of these studies was to assess efficacies of fungicides for foliar disease management and nematicides/seed treatment products for nematode management. The studies were conducted on growers’ land in Brookings and Volga Research Farm.

2018 Field Plot Summaries for Oat and Sorghum Foliar Disease Management Trials
An oat crown rust integrated management trial and a sorghum foliar fungicide trials were conducted to determine the efficacy of fungicides to manage crown rust and fungal diseases in oat and sorghum respectively. Crown rust is one of the most devastating diseases of oat in the state. Stragego fungicide was applied at three different timings to determine the most effective timing for crown rust management. For sorghum, the study investigated the efficacy of two different rates of Nexicor for managing sorghum foliar diseases. The oat field experiment was maintained at Northeast Research Farm (NERF), Southeast research farm (SERF) and Volga research farm. The sorghum experiment was at Volga.