All posts by Rachel Guyer, Plant Pathology Research Associate

Soilborne Pathogen Screening: 2017 Results and 2018 Screening

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Last week’s article discussed soilborne pathogens as ‘silent yield robbers’ of crops in production fields and the importance of screening. This article elaborates on two of the most common pathogens found in soybean fields, soybean cyst nematode (SCN) and charcoal rot, and presents the results from our 2017 soil screening. Continue reading


Taproot Decline: A new soybean disease for Tennessee

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Taproot decline (TRD) is a new disease to us in Tennessee and other states in the Southeast. A member of the genus (Xylaria) was first isolated from soybean in Ethiopia in the ‘70s , however researchers at that time did not confirm if this fungus was the pathogenic species that is now affecting soybeans across the southeastern US. The first report of taproot decline as a pathogen of soybean was published just last year, with sightings of this disease first occurring in 2007. Other states that have reported cases of TRD include Alabama, Mississippi, Louisiana, and Missouri with an increasingly northern range. A production field in Saulsbury (Hardeman County) was confirmed to have soybeans affected by TRD in August 2017, and two additional research fields in Gibson and Madison counties were confirmed in August 2018. Foliar symptoms were initially spotted at growth stage R6 (i.e. full seed); these foliar symptoms can easily be confused with those due to other diseases like sudden death syndrome and stem canker, and closer observation is needed for disease Continue reading