During the 2013 season I had the opportunity to rate the soybean variety trial plots for the presence of frogeye leaf spot as well as Cercospora blight (late-season Cercospora). Contained within this post are links to the rating data for the Maturity Group IV variety trial entries (MG IV early, MG IV late, and MG IV Conventional/Liberty Link varieties). Locations were rated based on a scale of 0 to 9 where 0=no disease present and 9=extreme disease characterized by leaves covered with frogeye leaf spot or, in the case of Cercospora blight, where leaves as well as pods and petioles were covered with purple/black discoloration associated with Cercospora blight.
Please note that tables include ratings from all of the locations and ratings may differ by location for each variety based on the environment encountered at that particular location during the season (e.g., compare Raymond to Falkner – Raymond was extremely dry throughout the 2013 season). In addition, some subtle differences may have occurred at some locations with regards to the particular strain of the fungus, especially in the case of frogeye leaf spot. The variability within the fungal population for this particular fungus can be extremely variable between two locations. When choosing a variety, consider the reaction of that particular variety across several environments. For the most part, varieties considered to be susceptible to frogeye leaf spot were susceptible at all locations rated.
Dots indicate missing values due to in most cases to complete leaf shed due to a late rating date.
Frogeye leaf spot and Cercospora blight ratings are contained in a separate file for each Maturity Group (either early, late, or conventional/liberty link). Each page is marked with the particular disease in the header so there is no confusion regarding specific disease ratings.
Maturity Group IV early – frogeye leaf spot ratings (Maturity Group IV early frogeye leaf spot ratings)
Maturity Group IV early – Cercospora blight ratings (Maturity Group IV early Cercospora blight ratings)
Maturity Group IV late – frogeye leaf spot ratings (Maturity Group IV late frogeye leaf spot ratings)
Maturity Group IV late – Cercospora blight ratings (Maturity Group IV late Cercospora blight ratings)
Maturity Group IV conventional/LibertyLink – frogeye leaf spot ratings (Maturity Group IV conventional-LibertyLink frogeye leaf spot ratings)
Maturity Group IV conventional/LibertyLink – Cercospora blight ratings (Maturity Group IV conventional-LibertyLink Cercospora blight ratings)
Maturity Group V variety trial ratings are available at: http://www.mississippi-crops.com/2014/01/26/2013-soybean-variety-trial-disease-ratings-maturity-group-v-frogeye-leaf-spot-and-cercospora-blight/