2017 Soybean OVT Foliar Disease Ratings: Maturity Group IV FINAL

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), Clarksdale, Hickory Flat, Longwood, Olive Branch, Raymond, Stoneville (n=3), and Tippo).  Entries were observed for their reaction to the diseases that occurred at each location. Cercospora blight, Septoria brown spot and Target spot were the three most common diseases encountered at each location.  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.  Cercospora leaf blight was evaluated 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 evlauated 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.

Note that locations with a non-irrigated trial are marked as location (N) with an “N” in parentheses to indicate non-irrigated.

Maturity Group IV Early (n=11 locations):

Cercospora blight (2017 MG IV early Cercospora blight ratings)

Septoria brown spot (2017 MG IV early Septoria brown spot ratings)

Target spot (2017 MG IV early target spot ratings)

Maturity Group IV Late (n=11 locations):

Cercospora blight (2017 MG IV late Cercospora blight ratings)

Septoria brown spot (2017 MG IV late Septoria brown spot ratings)

Target spot (2017 MG IV late target spot ratings)

Maturity Group IV Conventional (n=2 locations):

Cercospora blight (2017 MG IV Conventional Cercospora blight ratings)

Septoria brown spot (2017 MG IV Conventional Septoria brown spot ratings)

Target spot (2017 MG IV Conventional target spot ratings)

Maturity Group IV LibertyLink (n=4 locations):

Cercospora blight (2017 MG IV LL Cercospora blight ratings)

Septoria brown spot (2017 MG IV LL Septoria brown spot ratings)

Target spot (2017 MG IV LL target spot ratings)