amorph tuber rot problems

From: "Scott Taylor" staylor at brevardparks.com> on 2004.01.02 at 21:46:13(10978) Hello: The best of the New Year to everyone and I enjoy the list immensely. I have discussed this problem with a few of you already, off list, but thought that I would bring it up again, as it is continuing to plague me: I am trying to raise Am. paeoniifolius in some quantity for a few years now. I have been growing in containers, and I am having a continuing problem with a 'soft-rot' of tubers after harvest. I had some pathology work done on some of infected tubers last year and both Rhizopus and Verticillium spp. were found (fungi). The problem typically appears a week or two after harvest, mostly afflicting larger tubers (> 10 cm dia). I find it mostly ineffective to try and 'salvage' infected tubers: if I drastically cut away the infected portion and coat with fungicide, the lesions continue to spread. I altered my growing strategy in several ways this year: 1) brand new potting soil (no more 'reuse' of soil), 2) regular soil drenches with fungicide (Mancozeb)- 4-5 times during the growing season, 3) drench tuber in fungicide after harvest. I am growing to dormancy and handle the tubers with the greatest care during and after harvest (stored cool and dry). However, the problem continues, to a lesser degree perhaps, but still very disconcerting. I suspect that one error I am making is using a soil mixture that is not well enough drained, but I can't believe that with all of the fungicide that I am still experiencing this. Of course, here in Florida where 10 cm of rain may fall on a July afternoon, a 'well-drained' mixture may not apply! Any and all ideas welcome! Many thanks! D. Scott Taylor, Ph.D. Brevard County Environmentally Endangered Lands (EEL) Program Central Region Land Manager 5560 North US Highway 1 Melbourne, FL 32940 +More tel: 321.255.4466 FAX: 321.255.4499 email: staylor@brevardparks.com

From: rajshekhar misra rajshekharmisra at yahoo.com> on 2004.01.03 at 05:19:18(10979) Dear Dr.Taylor A very happy new year. Tuber rot in A.paeoniifolius is a serious problem at times. I am sure you may be starting with healthy planting material. The soil should be certainly well drained. Please check for nematode population in the potting mixture. Meloidogyne incognita infests the roots and tubers paving way for a lot of secondary pathogens. If you can afford to discard the infected planting material and start with fresh planting material providing proper soil drainage, the problem could be controlled. Regards +More R.S.Misra --- Scott Taylor wrote: > Hello: The best of the New Year to everyone and I > enjoy the list immensely. > I have discussed this problem with a few of you > already, off list, but > thought that I would bring it up again, as it is > continuing to plague me: I > am trying to raise Am. paeoniifolius in some > quantity for a few years now. > I have been growing in containers, and I am having a > continuing problem with > a 'soft-rot' of tubers after harvest. I had some > pathology work done on > some of infected tubers last year and both Rhizopus > and Verticillium spp. > were found (fungi). The problem typically appears > a week or two after > harvest, mostly afflicting larger tubers (> 10 cm > dia). I find it mostly > ineffective to try and 'salvage' infected tubers: if > I drastically cut away > the infected portion and coat with fungicide, the > lesions continue to > spread. I altered my growing strategy in several > ways this year: 1) brand > new potting soil (no more 'reuse' of soil), 2) > regular soil drenches with > fungicide (Mancozeb)- 4-5 times during the growing > season, 3) drench tuber > in fungicide after harvest. I am growing to > dormancy and handle the tubers > with the greatest care during and after harvest > (stored cool and dry). > However, the problem continues, to a lesser degree > perhaps, but still very > disconcerting. I suspect that one error I am making > is using a soil mixture > that is not well enough drained, but I can't believe > that with all of the > fungicide that I am still experiencing this. Of > course, here in Florida > where 10 cm of rain may fall on a July afternoon, a > 'well-drained' mixture > may not apply! Any and all ideas welcome! Many > thanks! > > D. Scott Taylor, Ph.D. > Brevard County Environmentally Endangered Lands > (EEL) Program > Central Region Land Manager > 5560 North US Highway 1 > Melbourne, FL 32940 > tel: 321.255.4466 > FAX: 321.255.4499 > email: staylor@brevardparks.com > > __________________________________ Do you Yahoo!? New Yahoo! Photos - easier uploading and sharing. http://photos.yahoo.com/

From: "Petra Schmidt" petra at plantdelights.com> on 2004.01.04 at 15:19:52(10981) Hello Scott, Are you letting the tubers dry off completely before placing them into cool storage? And have you tried storing them in warmer temperatures (what is your cool storage temp?). I've seen tuber rot become a real problem with wet cold conditions during dormancy and even during the leaf collapsing pre-dormancy stage; we're getting tubers out of ground beds or out of cool wet growing conditions to let them dry off in dry warmth and light before placing them into winter storage. Our winter storage is about 45 degrees F and dry. Have you tried using a powder fungicide, instead of a drench, after harvest? Again, keeping the tubers as dry as possible once they're out of the ground/pots is critical, in my growing experience here in North Carolina...a liquid drench at the end of the growing season would not be a good idea here but coating the suspected problem tubers in powdered fungicide and letting them dry off is a better option here. Keep us posted, please... Petra +More ----- Original Message ----- To: Sent: Friday, January 02, 2004 4:46 PM Subject: [aroid-l] amorph tuber rot problems > Hello: The best of the New Year to everyone and I enjoy the list immensely. > I have discussed this problem with a few of you already, off list, but > thought that I would bring it up again, as it is continuing to plague me: I > am trying to raise Am. paeoniifolius in some quantity for a few years now. > I have been growing in containers, and I am having a continuing problem with > a 'soft-rot' of tubers after harvest. I had some pathology work done on > some of infected tubers last year and both Rhizopus and Verticillium spp. > were found (fungi). The problem typically appears a week or two after > harvest, mostly afflicting larger tubers (> 10 cm dia). I find it mostly > ineffective to try and 'salvage' infected tubers: if I drastically cut away > the infected portion and coat with fungicide, the lesions continue to > spread. I altered my growing strategy in several ways this year: 1) brand > new potting soil (no more 'reuse' of soil), 2) regular soil drenches with > fungicide (Mancozeb)- 4-5 times during the growing season, 3) drench tuber > in fungicide after harvest. I am growing to dormancy and handle the tubers > with the greatest care during and after harvest (stored cool and dry). > However, the problem continues, to a lesser degree perhaps, but still very > disconcerting. I suspect that one error I am making is using a soil mixture > that is not well enough drained, but I can't believe that with all of the > fungicide that I am still experiencing this. Of course, here in Florida > where 10 cm of rain may fall on a July afternoon, a 'well-drained' mixture > may not apply! Any and all ideas welcome! Many thanks! > > D. Scott Taylor, Ph.D. > Brevard County Environmentally Endangered Lands (EEL) Program > Central Region Land Manager > 5560 North US Highway 1 > Melbourne, FL 32940 > tel: 321.255.4466 > FAX: 321.255.4499 > email: staylor@brevardparks.com > >

From: "Scott Taylor" staylor at brevardparks.com> on 2004.01.05 at 15:20:20(10986) Dr. Misra: Thank you again for your kindly response. As you might recall, you had sent me an extensive correspondence last year when I was researching this problem. I have followed much of your advise, but think that I am still making a mistake in trying to 'reuse' damaged tubers (which I hate to discard!). I did not separate plantings from damaged material from 'good' material, so it could be that the recurrent problems are from that diseased material that was reused. I do not see the typical evidence of nematode infections (blisters, etc.) but that is something I should check further. I will try and keep better track of this next year. Thank you again! dst +More D. Scott Taylor, Ph.D. Brevard County Environmentally Endangered Lands (EEL) Program Central Region Land Manager 5560 North US Highway 1 Melbourne, FL 32940 tel: 321.255.4466 FAX: 321.255.4499 email: staylor@brevardparks.com -----Original Message----- [mailto:aroid-l-owner@lists.ncsu.edu]On Behalf Of rajshekhar misra Sent: Saturday, January 03, 2004 12:19 AM To: aroid-l@lists.ncsu.edu Subject: Re: [aroid-l] amorph tuber rot problems Dear Dr.Taylor A very happy new year. Tuber rot in A.paeoniifolius is a serious problem at times. I am sure you may be starting with healthy planting material. The soil should be certainly well drained. Please check for nematode population in the potting mixture. Meloidogyne incognita infests the roots and tubers paving way for a lot of secondary pathogens. If you can afford to discard the infected planting material and start with fresh planting material providing proper soil drainage, the problem could be controlled. Regards R.S.Misra --- Scott Taylor wrote: > Hello: The best of the New Year to everyone and I > enjoy the list immensely. > I have discussed this problem with a few of you > already, off list, but > thought that I would bring it up again, as it is > continuing to plague me: I > am trying to raise Am. paeoniifolius in some > quantity for a few years now. > I have been growing in containers, and I am having a > continuing problem with > a 'soft-rot' of tubers after harvest. I had some > pathology work done on > some of infected tubers last year and both Rhizopus > and Verticillium spp. > were found (fungi). The problem typically appears > a week or two after > harvest, mostly afflicting larger tubers (> 10 cm > dia). I find it mostly > ineffective to try and 'salvage' infected tubers: if > I drastically cut away > the infected portion and coat with fungicide, the > lesions continue to > spread. I altered my growing strategy in several > ways this year: 1) brand > new potting soil (no more 'reuse' of soil), 2) > regular soil drenches with > fungicide (Mancozeb)- 4-5 times during the growing > season, 3) drench tuber > in fungicide after harvest. I am growing to > dormancy and handle the tubers > with the greatest care during and after harvest > (stored cool and dry). > However, the problem continues, to a lesser degree > perhaps, but still very > disconcerting. I suspect that one error I am making > is using a soil mixture > that is not well enough drained, but I can't believe > that with all of the > fungicide that I am still experiencing this. Of > course, here in Florida > where 10 cm of rain may fall on a July afternoon, a > 'well-drained' mixture > may not apply! Any and all ideas welcome! Many > thanks! > > D. Scott Taylor, Ph.D. > Brevard County Environmentally Endangered Lands > (EEL) Program > Central Region Land Manager > 5560 North US Highway 1 > Melbourne, FL 32940 > tel: 321.255.4466 > FAX: 321.255.4499 > email: staylor@brevardparks.com > > __________________________________ Do you Yahoo!? New Yahoo! Photos - easier uploading and sharing. http://photos.yahoo.com/

Note: this is a very old post, so no reply function is available.