2015 Soybean OVT Foliar Disease Ratings: Maturity Group V

Field evaluations of the Maturity Group IV entries in the MSU OVT were conducted at each of the locations where trials were planted (Brooksville, Clarksdale (n=2), Falkner, Longwood, Raymond, and Stoneville (n=3)).  Entries were observed for their reaction to the diseases that occurred at each location.  Cercospora blight and frogeye leaf spot were the two most commonly observed diseases; however, Septoria brown spot and Target spot were also observed at some locations.  Plots were observed between R6 and R6.5 and a second observation was made immediately prior to harvest to assess green stem severity (at all locations except Longwood).   Field evaluations for the presence of foliar disease were conducted using a 0 to 9 scale whereby 0=no disease and 9=excessive disease symptoms.  Leaf surface area affected was evaluated for FLS while CLB was rated based on the presence of disease on leaves (0 to 5), petioles (6), and on pods and stems (7 to 9) based on disease intensity as assessed by coloration of plant material (leaves with distinct purple coloration and petioles, pods and main stems with purple to near black coloration).  Septoria brown spot and target spot were rated in a similar fashion based on the presence of the disease within the plant canopy so that 0 to 3 indicated the presence in the lower canopy, 4 to 5 in the middle canopy, 6 to 8 in the upper canopy, and 9 indicative of extensive defoliation throughout the entire plant canopy and the disease in the upper most canopy.

Yield information, in Excel or pdf files, are available in a preliminary form on the MSU Variety testing website that can be accessed by following this link:

http://www.mafes.msstate.edu/variety-trials/includes/crops/soybeans.asp

Maturity Group V Early:

Cercospora blight (n=7 locations) (2015 MG V early Cercospora)

Frogeye leaf spot (n=7 locations) (2015 MG V early Frogeye)

Septoria brown spot (n=7 locations) (2015 MG V early Septoria)

Target spot (n=5 locations) (2015 MG V early Target)

Green stem (n=6 locations) (2015 MG V early Green stem)

Maturity Group V Late:

Cercospora blight (n=7 locations) (2015 MG V late Cercospora)

Frogeye leaf spot (n=7 locations) (2015 MG V late Frogeye)

Septoria brown spot (n=7 locations) (2015 MG V late Septoria)

Target spot (n=5 locations) (2015 MG V late Target)

Green stem (n=6 locations) (2015 MG V late Green stem)

Maturity Group V Conventional:

Cercospora blight (n=1 location) (2015 MG V conventional Cercospora)

Frogeye leaf spot (n=1 location) (2015 MG V conventional Frogeye)

Septoria brown spot (n=1 location) (2015 MG V conventional Septoria)

Green stem (n=1 location) (2015 MG V conventional Green stem)

Maturity Group V LibertyLink:

Cercospora blight (n=3 locations) (2015 MG V LibertyLink Cercospora)

Frogeye leaf spot (n=3 locations) (2015 MG V LibertyLink Frogeye)

Septoria brown spot (n=3 locations) (2015 MG V LibertyLink Septoria)

Target spot (n=2 locations) (2015 MG V LibertyLink Target spot)

Green stem (n=3 locations) (2015 MG V LibertyLink Green stem)