2015 Soybean OVT Stem Canker Ratings

Clockwise from left, lesion associated with stem canker in an inoculated plant, a susceptible soybean variety exhibiting severe stem canker, interveinal chlorosis associated with stem canker, sporulation of the fungus on a stem-associated canker, “flagging” of infected soybean plants in a field exhibiting stem canker.

All of the entries in the 2015 Mississippi State Variety trials were evaluated for their reaction to the stem canker fungus.  Trials consisted of single rows of each cultivar planted in 10 foot plots and replicated 4 times.  Within each row, a total of 8 plants were inoculated with a single toothpick that contained the fungus that causes stem canker.  Plants were inoculated approximately 8 weeks post-planting.  Evaluations of stem canker severity were conducted between R6 and R6.5 by observing the stem of each inoculated plant for the presence of a canker.  Observations of each variety were conducted using a modified 0-9 scale.  Information contained within each table contain the analyzed stem canker rating as an average of all inoculated plants within a single plot.  In addition, each cultivar includes a stem canker designation: R=resistant, MR=moderately resistant, MS=moderately susceptible, S=susceptible.  In field situations where stem canker has been observed plant cultivars that have been observed to contain resistance to stem canker.  In addition, keep in mind that observations of stem canker tend to be more obvious when the environment is conducive for disease development.  Therefore, over time, and in years when the environment may not be conducive for the development of stem canker, it is possible that stem canker designations could change between years.

Maturity Group IV Early (2015 OVT stem canker MG IV early)

Maturity Group IV Late (2015 OVT stem canker MG IV late)

Maturity Group IV Conventional (2015 OVT stem canker MG IV conv)

Maturity Group IV LibertyLink (2015 OVT stem canker MG IV LL)

Maturity Group V Early (2015 OVT stem canker MG V early)

Maturity Group V Late (2015 OVT stem canker MG V late)

Maturity Group V Conventional (2015 OVT stem canker MG V conv)

Maturity Group V LibertyLink (2015 OVT stem canker MG V LL)