 Good morning. This is Ed Sakura extension plant pathologist today. We're going to talk about taproot decline, which is a new soil soil-borne fungal disease of soybeans Taproot decline is an emerging disease. We've we've picked it up in Alabama, Mississippi, Louisiana and Arkansas over the last few years We confirmed it in Alabama last year for the first time But I have observed symptoms of this pathogen or this disease and feels in previous years in the state The disease is caused by a previously undescribed fungal species in the genus xylaria so a new pathogen for soybeans These are some slides I took up at the Tennessee Valley Research Station last August This is out of someone's Kathy Glasses variety trial but you can just see some general yelling of the plants in the field and These symptoms can be confused at a number of other diseases such as sudden death syndrome Charcoal rot southern blight and so on but just a general yellow decline of the plant So foliar symptoms as I said can be confused with other soil-borne diseases most likely sudden death charcoal rot southern blight stem canker maybe even some herbicide injury problems You'll see a mild Intervainal chlorosis or yellowing. This is often common on leaves of infected plants You leaves exhibiting this intervainal chlorosis will develop in the mid canopy prior to bloom Which is a little a different from some of the other soil-borne diseases that show up later in the season You will see a leaf yellowing visible in the upper canopy at full pod Stages r5 r6 late in the season these this yellow flag is what you normally pick out when you're scouting a field The best way to Confirm taproot decline is by looking at the base of the plants looking at the blackened roots And oftentimes when you try and pull one of these plants out of the ground It'll snap off right at the soil line right at taproot and if you look at the base you'll see a black discoloration which Pretty characteristic for this pathogen On these images you can see some of the Confusion you might have in the field among the different diseases. I have been confused for the last couple years on this subject But you can see taproot decline developing in the bottom left corner Intervainal yellowing with eventual necrosis or browning of the tissue You compare that to sudden death syndrome sds in the bottom right Pretty much similar symptoms top right corner You have some Actually, that's a fungicide damage on soybeans with the intervainal Yellowing and browning and upper left is soybean vein necrosis virus also a relatively new disease in alabama And with that disease you can get yellow spotting and eventual necrosis or browning between the tissue So taproot decline not that easy to differentiate from some of these other pathogens What you'll see in the field usually by by podfill Is just yellow plants in the field flagging of individual plants, maybe one or two plants in a in a row But not a dramatic feel pattern such as coming in from the edge to say with charcoal Out or big round circles these plants are often scattered and you might find two or three plants together in a row When you look more closely at the plants If you get down in your hands and knees and look down you'll find one or two plants yellowing up Oftentimes right next to these you might find one or two dead plants that succumbed to the disease earlier in the season And then you also have this intervainal yellowing or chlorosis necrosis As I said can be confused with a number of other diseases Now with taproot decline you can't see the disease disease earlier in the season Even before bloom and if you look at the leaves in the left Some of that intervainal yellowing there can be confused with something like a iron Iron deficiency or magnesium So it can come in early And take those plants out early as well, but oftentimes this goes unnoticed by the farmer I hear symptoms on the cotyledon so But I've often seen that as looking like uh abiotic like damage from wind or or blowing soil most uh, I want to say dramatic, but most Except you really want to look for to confirm it is this black stromata at the base of the plant and the bottom right corner You can see this black lesion Base at the at the soil line on the plant On top there you can see the black the brown stuff is just soil adhering to the soil surface But that's the fungal body. That's a sign of the pathogen. That's the actual fungal stromata And again when you pull these plants from the soil that will just snap off very easily at the soil line One thing I'll be looking for this year and I haven't seen this in the past is Is uh dead man's fingers or devil's horns. These are the these white structures coming from the stromata At near the soil line or at the base of the plant and this is just a sign of the pathogen that you have it Something I'll be looking for this year But we'll do oftentimes in the lab, but you could also see this in the field is When you remove those plants from the ground and and cut the stem open longitudinally just above the soil line You'll see a white cottony growth within the pith And this could separate it from say internal symptoms of sudden death syndrome Which causes more of a water soaking on the lower vascular system without the white cottony growth So at this time we're surveying the state to determine disease distribution started this last year However, we're also working with pathologists at mississippi state university in lsu as well as other institutions in the southeast To determine the best management practices for this pathogen Right now research In the south will focus on identifying varietal resistance to tapere decline fungicide effectiveness crop rotation and tillage options Identifying alternative hosts for the pathogen and also estimate yield loss to this disease that does it cause is it a significant problem that We have to address Last slide here just a distribution map where we detected tapere decline last year in the state I think we picked it up in roughly eight counties And I I did notice in a couple counties in the black belt in west alabama and hail green pickings and sumpter I was not able to find a disease, but this just might have been due to field conditions or Certain varieties, but I think we'll find it more and more as we Canada's estate for tapere decline So with that if anyone has any questions on the disease, please contact me By phone or by email and I'll be happy to talk about it further. Thank you