Dr. Tom Allen, Extension Plant Pathologist at DREC-Stoneville, has posted ratings for various diseases that affect soybean varieties that were grown in the 2015 Mississippi Soybean Variety Trials.

Varieties were rated for indicated diseases at the locations indicated in the tables in the below linked article. Ratings were based on a scale of 0 to 9: for frogeye leaf spot, 0 = no disease present and 9 = severe disease symptoms; for Cercospora blight, 0 = no disease, 5 = disease present on leaves, and 9 = purple pods, petioles and stems; For Septoria brown spot and target spot, 0 = no disease, 1 = disease present on lowest leaves, 5 = disease present in middle of the canopy, and 9 = disease present in the upper canopy with severe defoliation. Green stem, where present, was rated on a 0-100% scale and indicates percentage of green stem malady on a whole plot basis.

Ratings are based on each variety’s reaction to natural infestations of each disease at each location; i.e., plants were not inoculated with disease pathogens. Thus, the ratings do not presume to indicate a variety’s response to a known yield-reducing level of the pathogen. Rather, the ratings are to be used as an indicator of each variety’s reaction to the level of the pathogen present at each location in 2015.

According to Dr. Allen, consider the reaction of a particular variety across several locations when assessing that variety’s susceptibility to the rated diseases.

Click here to view the ratings for each variety at each location (locations added as received).

Composed by Larry G. Heatherly, Nov. 2015, larryheatherly@bellsouth.net