2016 Soybean OVT Foliar Disease Ratings: Maturity Group IV

Field evaluations of the Maturity Group IV entries in the MSU OVT were conducted at each of the locations where trials were planted (Brooksville (n=2), Charleston, Clarksdale, Falkner, Hernando, 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.  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 IV Early (n=11 locations):

Cercospora blight (2016 MG IV Early Cercospora blight)

Frogeye leaf spot (2016 MG IV Early Frogeye leaf spot)

Septoria brown spot (2016 MG IV Early Septoria brown spot)

Target spot (2016 MG IV Early Target spot)

Maturity Group IV Late (n=11 locations):

Cercospora blight (2016 MG IV Late Cercospora blight)

Frogeye leaf spot (2016 MG IV Late Frogeye leaf spot)

Septoria brown spot (2016 MG IV Late Septoria brown spot)

Target spot (2016 MG IV Late Target spot)

Maturity Group IV Conventional (n=2 locations):

Cercospora blight (2016 MG IV Conventional Cercospora blight)

Frogeye leaf spot (2016 MG IV Conventional Frogeye leaf spot)

Septoria brown spot (2016 MG IV Conventional Septoria brown spot)

Target spot (2016 MG IV Conventional Target spot)

Maturity Group IV LibertyLink (n=4 locations):

Cercospora blight (n=4 locations) (2016 MG IV LibertyLink Cercospora blight)

Frogeye leaf spot (n=4 locations) (2016 MG IV LibertyLink Frogeye leaf spot)

Septoria brown spot (n=3 locations) (2016 MG IV LibertyLink Septoria brown spot)

Target spot (n=2 locations) (2016 MG IV LibertyLink Target spot)

Maturity Group IV Xtend (n=5 locations):

Cercospora blight (2016 MG IV Xtend Cercospora blight)

Frogeye leaf spot (2016 MG IV Xtend Frogeye leaf spot)

Septoria brown spot (2016 MG IV Xtend Septoria brown spot)

Target spot (2016 MG IV Xtend Target spot)