2016 Soybean Stem Canker Variety Trial Evaluations

Stem canker lesion as a result of a toothpick inoculation.

All of the entries in the 2016 Mississippi State University Official Variety Trials (OVT) were evaluated for their reaction to the stem canker fungus.  In addition, a few varieties were added to supplement the trials and obtain information on those particular varieties that were not entered by the respective companies in the MSU-OVT.  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 (four isolates of the fungus were used for a fungal cocktail on toothpicks).  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.  Moreover, as additional fungal isolates are added to the collection it is possible that the rating as well as cultivar designation can change accordingly.

RoundUp Ready varieties:

Maturity Group III (2016-ovt-stem-canker-mg-iii)

Maturity Group IV Early (2016-ovt-stem-canker-mg-iv-early)

Maturity Group IV Late (2016-ovt-stem-canker-mg-iv-late)

Maturity Group V Early (2016-ovt-stem-canker-mg-v-early)

Maturity Group V Late (2016-ovt-stem-canker-mg-v-late)

Xtend varieties:

Maturity Group IV Xtend (2016-ovt-stem-canker-mg-iv-xtend)

Maturity Group V Xtend (2016-ovt-stem-canker-mg-v-xtend)

Conventional varieties:

Maturity Group IV Conventional (2016-ovt-stem-canker-mg-iv-conventional)

Maturity Group V Conventional (2016-ovt-stem-canker-mg-v-conventional)

LibertyLink varieties:

Maturity Group IV LibertyLink (2016-ovt-stem-canker-mg-iv-libertylink)

Maturity Group V LibertyLink (2016-ovt-stem-canker-mg-v-libertylink)