Re: Apple-Crop: Fireblight on Ernst Bosch - what are the mechanisms of re-infection?
Hello, as you know, there is a lot more information on bloom infection than anything else. So I don't think anyone has all the answers to your questions. Further, many possibilities can coexist with varying degrees of importance. In other words: it is VERY possible to inoculate a tree with shears that were dipped in bacteria... But who would do that? In real life situation, people would use clean shears and cut through healthy wood. As for cankers: sometimes we see them sometimes we don't. Bacteria can be systemic within the tree. The tree can recover from some systemic bacteria, but this must be limited. but long term I can't afford having a single tree harboring fireblight in my orchard. You're assuming bacteria will stay on this tree forever. In our experiment, once the trees were cleaned from symptoms during the season (several visits) then that tree had the same probability of infection as any other tree in the orchard... Vincent Vincent Philion, agr., M.Sc. Phytopathologiste Laboratoire de production fruitière intégrée Institut de recherche et de développement en agroenvironnement 335, Rang des vingt-cinq Est Case postale 24 Saint-Bruno-de-Montarville (Québec) J3V 4P8 Tél. bureau: 450 653-7368 poste 224 Tél. laboratoire: 450 653-7368 poste 229 Cellulaire: 514-623-8275 Autre: 802-659-4282 Télécopie: 450 653-1927 Verger du parc national du Mont-Saint-Bruno 330, Rang des vingt-cinq Est Case postale 24 Saint-Bruno-de-Montarville (Québec) J3V 4P8 Téléphone et télécopieur : 450 653-8375 Courriel: vincent.phil...@irda.qc.ca Site Internet: www.irda.qc.ca Avez-vous réellement besoin d'imprimer ce courriel? Si oui, imprimez- le recto-verso! AVIS DE CONFIDENTIALITÉ Ce message peut contenir de l'information de nature privilégiée et confidentielle. Si vous n'êtes pas le destinataire visé ou croyez l'avoir reçu par erreur, nous vous saurions gré d'en aviser l'émetteur. Si ce message vous a été transmis par erreur, veuillez le détruire sans en communiquer le contenu à d'autres personnes ou le reproduire.
Re: Apple-Crop: Fireblight on Ernst Bosch
Hi! we tried to restart trees by leaving a few nodes above the graft, but failed miserably. The darn trees never re-sprouted. We had much better success pruning out the diseased portions. We also found sterilizing shears was a waste of time. The article can be found at: Toussaint, V., and Philion, V. 2007. NATURAL EPIDEMIC OF FIRE BLIGHT IN A NEWLY PLANTED ORCHARD AND EFFECT OF PRUNING ON DISEASE DEVELOPMENT. In XI International Workshop on Fire Blight 793, ISHS, p. 313-320. Vincent On 18-Jun-2009, at 2:17 PM, Mark Longstroth wrote: Good Job Allen. I discussed that type of program Monday with a grower. Other sad fireblight tales. I had a grower who planted RubiJon this spring, which bloomed after normal and now have blossom blight. I suggested cutting back to 2 or 3 nodes above the graft union in an effort to save the rootstock (M26) on any tree that showed any symptoms. He also had a block of Idared on G30 which got fireblight in the fall (leaf hoppers?). He noticed 30 dead trees out of 150 this winter when he pruned but about half the planting has or is collapsing now and he will remove them all. - Mark Longstroth SW Michigan District Fruit Educator Van Buren County MSU Extension Email - longs...@msu.edu http://web1.msue.msu.edu/vanburen/disthort.htm - -Original Message- From: apple-crop@virtualorchard.net [mailto:apple-crop@virtualorchard.net ]On Behalf Of Allen Teach - Sunrise Orchard Sent: Thursday, June 18, 2009 1:01 PM To: Apple-Crop Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Gentlemen: I certainly agree with Mark to get rid of the culprit tree yesterday. However, let me relay an experience we had last year. On a five acre block of 3rd leaf Honeycrisp on B9 and CG 16 (tall spindle) we had some blossom blight on very late rat tail bloom and began seeing sporadic shoot blight in late June. I immediately made ugly stub cuts on the affected branches, fired up the sprayer and applied Apogee to the entire block. I continued to patrol the block and reapplied the Apogee about 3 weeks later. this is totally unscientific but we were able to avoid a disaster. Granted Honeycrisp/B9-CG 16 is not extremely susceptible but we had the trees set up with water and fertilizer to grow vigorously. Allen Teach Sunrise Orchards Inc. Gays Mills, WI P.S. Let's all dodge the severe weather the next couple of days! - Original Message - From: Axel Kratel To: Apple-Crop Sent: Thursday, June 18, 2009 11:18 AM Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Mark, that sounds like good advice. Basically, I cut once, that didn't help. I cut again. if it comes back again I will yank out the tree. I do have a question for the group: When fireblight die back shows up as a result of flowers getting rained on, which of these two reasons would cause it: 1) Fireblight is systemic in the tree 2) Fireblight was brought to the tree from an outside vector. Thanks. From: Mark Longstroth longs...@msu.edu To: Apple-Crop apple-crop@virtualorchard.net Sent: Thursday, June 18, 2009 7:36:12 AM Subject: RE: Apple-Crop: Fireblight on Ernst Bosch Axel, If I had a 4 year old tree in an orchard of 200 trees with fireblight that bad, I would yank it out of the ground today! In my experience, 4 year old trees with that bad an infection don't survive. It sounds like the bacteria is running faster than you can cut and in my experience it will run very fast in wood back through three year old wood and in a 4 year old tree it is just a short jump to the rootstock. MM111 is rated as moderately resistant and I doubt it will survive with an infected susceptible scion such as you describe. If you inject strep into the tree you might save it or find out that you have a resistant strain in your orchard. Do you really want a source of fireblight in your orchard while you try to save one tree? What are you going to do if you have a storm which spreads the infection to other trees? Get rid of it now while the infection is only in one tree. It is much easier to manage fireblight if you do not have a source in the orchard. I saw fireblight literally destroy hundreds of acres of apple trees in 2000 here in SW Michigan. The industry still has not recovered from that epidemic. - Mark Longstroth SW Michigan District Fruit Educator Van Buren County MSU Extension Email - longs...@msu.edu http://web1.msue.msu.edu/vanburen/disthort.htm - -Original Message- From: apple-crop@virtualorchard.net [mailto:apple-crop@virtualorchard.net ]On Behalf Of Axel Kratel Sent: Wednesday, June 17, 2009 12:19 AM To: Apple-Crop Subject: Apple-Crop: Fireblight on Ernst Bosch Dear all, I have an Ernst Bosch apple tree on MM111 that has developed a pretty bad case of fireblight
Re: Apple-Crop: Fireblight on Ernst Bosch
I finally figured out what is going on. Because of the earlier infection, the tree bark is covered with fireblight bacteria even though the wood is not infected. A cut with pruning sheers inevitably re-infects the tree at the cut location. A real important step in controlling fireblight is to fully sterilize the tree, or sterilize the cut area before pruning, sterilize after pruning, and seal the cut so that the fireblight bacteria present on the bark on surrounding branches can't infect the tree. From: Vincent Philion vincent.phil...@irda.qc.ca To: Apple-Crop apple-crop@virtualorchard.net Sent: Monday, June 22, 2009 1:20:12 PM Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Hi! we tried to restart trees by leaving a few nodes above the graft, but failed miserably. The darn trees never re-sprouted. We had much better success pruning out the diseased portions. We also found sterilizing shears was a waste of time. The article can be found at: Toussaint, V., and Philion, V. 2007. NATURAL EPIDEMIC OF FIRE BLIGHT IN A NEWLY PLANTED ORCHARD AND EFFECT OF PRUNING ON DISEASE DEVELOPMENT. In XI International Workshop on Fire Blight 793, ISHS, p. 313-320. Vincent On 18-Jun-2009, at 2:17 PM, Mark Longstroth wrote: Good Job Allen. I discussed that type of program Monday with a grower. Other sad fireblight tales. I had a grower who planted RubiJon this spring, which bloomed after normal and now have blossom blight. I suggested cutting back to 2 or 3 nodes above the graft union in an effort to save the rootstock (M26) on any tree that showed any symptoms. He also had a block of Idared on G30 which got fireblight in the fall (leaf hoppers?). He noticed 30 dead trees out of 150 this winter when he pruned but about half the planting has or is collapsing now and he will remove them all. - Mark Longstroth SW Michigan District Fruit Educator Van Buren County MSU Extension Email - longs...@msu.edu http://web1.msue.msu.edu/vanburen/disthort.htm - -Original Message- From: apple-crop@virtualorchard.net [mailto:apple-c...@virtualorchard.net]on Behalf Of Allen Teach - Sunrise Orchard Sent: Thursday, June 18, 2009 1:01 PM To: Apple-Crop Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Gentlemen: I certainly agree with Mark to get rid of the culprit tree yesterday. However, let me relay an experience we had last year. On a five acre block of 3rd leaf Honeycrisp on B9 and CG 16 (tall spindle) we had some blossom blight on very late rat tail bloom and began seeing sporadic shoot blight in late June. I immediately made ugly stub cuts on the affected branches, fired up the sprayer and applied Apogee to the entire block. I continued to patrol the block and reapplied the Apogee about 3 weeks later. this is totally unscientific but we were able to avoid a disaster. Granted Honeycrisp/B9-CG 16 is not extremely susceptible but we had the trees set up with water and fertilizer to grow vigorously. Allen Teach Sunrise Orchards Inc. Gays Mills, WI P.S. Let's all dodge the severe weather the next couple of days! - Original Message - From: Axel Kratel To: Apple-Crop Sent: Thursday, June 18, 2009 11:18 AM Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Mark, that sounds like good advice. Basically, I cut once, that didn't help. I cut again. if it comes back again I will yank out the tree. I do have a question for the group: When fireblight die back shows up as a result of flowers getting rained on, which of these two reasons would cause it: 1) Fireblight is systemic in the tree 2) Fireblight was brought to the tree from an outside vector. Thanks. From: Mark Longstroth longs...@msu.edu To: Apple-Crop apple-crop@virtualorchard.net Sent: Thursday, June 18, 2009 7:36:12 AM Subject: RE: Apple-Crop: Fireblight on Ernst Bosch Axel, If I had a 4 year old tree in an orchard of 200 trees with fireblight that bad, I would yank it out of the ground today! In my experience, 4 year old trees with that bad an infection don't survive. It sounds like the bacteria is running faster than you can cut and in my experience it will run very fast in wood back through three year old wood and in a 4 year old tree it is just a short jump to the rootstock. MM111 is rated as moderately resistant and I doubt it will survive with an infected susceptible scion such as you describe. If you inject strep into the tree you might save it or find out that you have a resistant strain in your orchard. Do you really want a source of fireblight in your orchard while you try to save one tree? What are you going to do if you have a storm which spreads the infection to other trees? Get rid of it now while the infection is only in one tree. It is much easier to manage fireblight if you do not have a source in the orchard. I saw
Re: Apple-Crop: Fireblight on Ernst Bosch
Hello Axel, For three consecutive years we compared sterile shears vs non sterile shears. As long as you are cutting in healthy wood (obviously) we observed the same percentage of reinfection. I'm not sure what data you have to support your claim, but our observations simply don't support what you write. In the article we conclude that speed of intervention is the key. Anything that will slow you down, including sterilizing shears or tree or wound or whatever, is more detrimental than simply cutting out diseased branches as fast as you can. The real key is to get as many of these diseased branches off the trees. This limits disease spread to other trees. Furthermore, the longer diseased branches stay on the tree, the longer they pump bacteria down the tree and into the rootstock, the higher the likelihood of death. Other considerations are minor. Vincent On 22-Jun-2009, at 4:54 PM, Axel Kratel wrote: I finally figured out what is going on. Because of the earlier infection, the tree bark is covered with fireblight bacteria even though the wood is not infected. A cut with pruning sheers inevitably re-infects the tree at the cut location. A real important step in controlling fireblight is to fully sterilize the tree, or sterilize the cut area before pruning, sterilize after pruning, and seal the cut so that the fireblight bacteria present on the bark on surrounding branches can't infect the tree. From: Vincent Philion vincent.phil...@irda.qc.ca To: Apple-Crop apple-crop@virtualorchard.net Sent: Monday, June 22, 2009 1:20:12 PM Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Hi! we tried to restart trees by leaving a few nodes above the graft, but failed miserably. The darn trees never re-sprouted. We had much better success pruning out the diseased portions. We also found sterilizing shears was a waste of time. The article can be found at: Toussaint, V., and Philion, V. 2007. NATURAL EPIDEMIC OF FIRE BLIGHT IN A NEWLY PLANTED ORCHARD AND EFFECT OF PRUNING ON DISEASE DEVELOPMENT. In XI International Workshop on Fire Blight 793, ISHS, p. 313-320. Vincent On 18-Jun-2009, at 2:17 PM, Mark Longstroth wrote: Good Job Allen. I discussed that type of program Monday with a grower. Other sad fireblight tales. I had a grower who planted RubiJon this spring, which bloomed after normal and now have blossom blight. I suggested cutting back to 2 or 3 nodes above the graft union in an effort to save the rootstock (M26) on any tree that showed any symptoms. He also had a block of Idared on G30 which got fireblight in the fall (leaf hoppers?). He noticed 30 dead trees out of 150 this winter when he pruned but about half the planting has or is collapsing now and he will remove them all. - Mark Longstroth SW Michigan District Fruit Educator Van Buren County MSU Extension Email - longs...@msu.edumailto:longs...@msu.edu http://web1.msue.msu.edu/vanburen/disthort.htm - -Original Message- From: apple-crop@virtualorchard.netmailto:apple-crop@virtualorchard.net [mailto:apple-c...@virtualorchard.net]on Behalf Of Allen Teach - Sunrise Orchard Sent: Thursday, June 18, 2009 1:01 PM To: Apple-Crop Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Gentlemen: I certainly agree with Mark to get rid of the culprit tree yesterday. However, let me relay an experience we had last year. On a five acre block of 3rd leaf Honeycrisp on B9 and CG 16 (tall spindle) we had some blossom blight on very late rat tail bloom and began seeing sporadic shoot blight in late June. I immediately made ugly stub cuts on the affected branches, fired up the sprayer and applied Apogee to the entire block. I continued to patrol the block and reapplied the Apogee about 3 weeks later. this is totally unscientific but we were able to avoid a disaster. Granted Honeycrisp/B9-CG 16 is not extremely susceptible but we had the trees set up with water and fertilizer to grow vigorously. Allen Teach Sunrise Orchards Inc. Gays Mills, WI P.S. Let's all dodge the severe weather the next couple of days! - Original Message - From: Axel Kratelmailto:axel.kra...@yahoo.com To: Apple-Cropmailto:apple-crop@virtualorchard.net Sent: Thursday, June 18, 2009 11:18 AM Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Mark, that sounds like good advice. Basically, I cut once, that didn't help. I cut again. if it comes back again I will yank out the tree. I do have a question for the group: When fireblight die back shows up as a result of flowers getting rained on, which of these two reasons would cause it: 1) Fireblight is systemic in the tree 2) Fireblight was brought to the tree from an outside vector. Thanks. From: Mark Longstroth longs...@msu.edumailto:longs...@msu.edu To: Apple-Crop
Re: Apple-Crop: Fireblight on Ernst Bosch
The question is, what happens to the bacteria when it gets warmer? Does it just go dormant in the tree? My understanding is that moisture availability drives secondary cycles of the population. Warmer weather won't help unless it leads to drier weather. When dry weather begins to prevail, the bacterium will cease to spread but remain systemic in the tree. Thats why its such a difficult disease to manage. Lets just hope it gets drier. For us it's the wettest Spring I can remember around Chicago. We entered June about 10 ahead of normal for the year. We have had 5 in June so far. Its raining now with rain forecasted 3 of the next 5 days. Bill William H Shoemaker, UI-NRES Sr Research Specialist, Food Crops St Charles Horticulture Research Center 535 Randall Road St Charles, IL 60174 630-584-7254; FAX-584-4610 -- The 'Apple-Crop' LISTSERV is sponsored by the Virtual Orchard http://www.virtualorchard.net and managed by Win Cowgill and Jon Clements webmas...@virtualorchard.net. Apple-Crop is not moderated. Therefore, the statements do not represent official opinions and the Virtual Orchard takes no responsibility for the content.
RE: Apple-Crop: Fireblight on Ernst Bosch
Axel, If I had a 4 year old tree in an orchard of 200 trees with fireblight that bad, I would yank it out of the ground today! In my experience, 4 year old trees with that bad an infection don't survive. It sounds like the bacteria is running faster than you can cut and in my experience it will run very fast in wood back through three year old wood and in a 4 year old tree it is just a short jump to the rootstock. MM111 is rated as moderately resistant and I doubt it will survive with an infected susceptible scion such as you describe. If you inject strep into the tree you might save it or find out that you have a resistant strain in your orchard. Do you really want a source of fireblight in your orchard while you try to save one tree? What are you going to do if you have a storm which spreads the infection to other trees? Get rid of it now while the infection is only in one tree. It is much easier to manage fireblight if you do not have a source in the orchard. I saw fireblight literally destroy hundreds of acres of apple trees in 2000 here in SW Michigan. The industry still has not recovered from that epidemic. - Mark Longstroth SW Michigan District Fruit Educator Van Buren County MSU Extension Email - longs...@msu.edu http://web1.msue.msu.edu/vanburen/disthort.htm - -Original Message- From: apple-crop@virtualorchard.net [mailto:apple-c...@virtualorchard.net]on Behalf Of Axel Kratel Sent: Wednesday, June 17, 2009 12:19 AM To: Apple-Crop Subject: Apple-Crop: Fireblight on Ernst Bosch Dear all, I have an Ernst Bosch apple tree on MM111 that has developed a pretty bad case of fireblight. I have over 200 trees and I've never seen fireblight here before, so this is a first for me. Symptoms included the classic die back with the orange colored droplets. I've cut the infected wood, and applied serenade, and I've had to go back twice now to cut more. I've cut back quite far, yet the cuts are still turning orange. I disinfected sheers in between cuts. On the last cuts I've resorted to treating the cuts with hydrogen peroxide, but it seems hopeless. Any hope of saving the tree or should I sacrifice it? It's on it's fourth leaf. I am surprised that this variety is so susceptible. The literature claims it's not especially sensitive to fireblight. Thanks for your advice. I am willing to forgo organic to save a tree, so if there's any sort of systemic treatment that would be possible, I would consider it. Serenade is a good preventative, but it's too late for this tree.
Re: Apple-Crop: Fireblight on Ernst Bosch
Mark, that sounds like good advice. Basically, I cut once, that didn't help. I cut again. if it comes back again I will yank out the tree. I do have a question for the group: When fireblight die back shows up as a result of flowers getting rained on, which of these two reasons would cause it: 1) Fireblight is systemic in the tree 2) Fireblight was brought to the tree from an outside vector. Thanks. From: Mark Longstroth longs...@msu.edu To: Apple-Crop apple-crop@virtualorchard.net Sent: Thursday, June 18, 2009 7:36:12 AM Subject: RE: Apple-Crop: Fireblight on Ernst Bosch Axel, If I had a 4 year old tree in an orchard of 200 trees with fireblight that bad, I would yank it out of the ground today! In my experience, 4 year old trees with that bad an infection don't survive. It sounds like the bacteria is running faster than you can cut and in my experience it will run very fast in wood back through three year old wood and in a 4 year old tree it is just a short jump to the rootstock. MM111 is rated as moderately resistant and I doubt it will survive with an infected susceptible scion such as you describe. If you inject strep into the tree you might save it or find out that you have a resistant strain in your orchard. Do you really want a source of fireblight in your orchard while you try to save one tree? What are you going to do if you have a storm which spreads the infection to other trees? Get rid of it now while the infection is only in one tree. It is much easier to manage fireblight if you do not have a source in the orchard. I saw fireblight literally destroy hundreds of acres of apple trees in 2000 here in SW Michigan. The industry still has not recovered from that epidemic. - Mark Longstroth SW Michigan District Fruit Educator Van Buren County MSU Extension Email - longs...@msu.edu http://web1.msue.msu.edu/vanburen/disthort.htm - -Original Message- From: apple-crop@virtualorchard.net [mailto:apple-c...@virtualorchard.net]on Behalf Of Axel Kratel Sent: Wednesday, June 17, 2009 12:19 AM To: Apple-Crop Subject: Apple-Crop: Fireblight on Ernst Bosch Dear all, I have an Ernst Bosch apple tree on MM111 that has developed a pretty bad case of fireblight. I have over 200 trees and I've never seen fireblight here before, so this is a first for me. Symptoms included the classic die back with the orange colored droplets. I've cut the infected wood, and applied serenade, and I've had to go back twice now to cut more. I've cut back quite far, yet the cuts are still turning orange. I disinfected sheers in between cuts. On the last cuts I've resorted to treating the cuts with hydrogen peroxide, but it seems hopeless. Any hope of saving the tree or should I sacrifice it? It's on it's fourth leaf. I am surprised that this variety is so susceptible. The literature claims it's not especially sensitive to fireblight. Thanks for your advice. I am willing to forgo organic to save a tree, so if there's any sort of systemic treatment that would be possible, I would consider it. Serenade is a good preventative, but it's too late for this tree.
Re: Apple-Crop: Fireblight on Ernst Bosch
Gentlemen: I certainly agree with Mark to get rid of the culprit tree yesterday. However, let me relay an experience we had last year. On a five acre block of 3rd leaf Honeycrisp on B9 and CG 16 (tall spindle) we had some blossom blight on very late rat tail bloom and began seeing sporadic shoot blight in late June. I immediately made ugly stub cuts on the affected branches, fired up the sprayer and applied Apogee to the entire block. I continued to patrol the block and reapplied the Apogee about 3 weeks later. this is totally unscientific but we were able to avoid a disaster. Granted Honeycrisp/B9-CG 16 is not extremely susceptible but we had the trees set up with water and fertilizer to grow vigorously. Allen Teach Sunrise Orchards Inc. Gays Mills, WI P.S. Let's all dodge the severe weather the next couple of days! - Original Message - From: Axel Kratel To: Apple-Crop Sent: Thursday, June 18, 2009 11:18 AM Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Mark, that sounds like good advice. Basically, I cut once, that didn't help. I cut again. if it comes back again I will yank out the tree. I do have a question for the group: When fireblight die back shows up as a result of flowers getting rained on, which of these two reasons would cause it: 1) Fireblight is systemic in the tree 2) Fireblight was brought to the tree from an outside vector. Thanks. -- From: Mark Longstroth longs...@msu.edu To: Apple-Crop apple-crop@virtualorchard.net Sent: Thursday, June 18, 2009 7:36:12 AM Subject: RE: Apple-Crop: Fireblight on Ernst Bosch Axel, If I had a 4 year old tree in an orchard of 200 trees with fireblight that bad, I would yank it out of the ground today! In my experience, 4 year old trees with that bad an infection don't survive. It sounds like the bacteria is running faster than you can cut and in my experience it will run very fast in wood back through three year old wood and in a 4 year old tree it is just a short jump to the rootstock. MM111 is rated as moderately resistant and I doubt it will survive with an infected susceptible scion such as you describe. If you inject strep into the tree you might save it or find out that you have a resistant strain in your orchard. Do you really want a source of fireblight in your orchard while you try to save one tree? What are you going to do if you have a storm which spreads the infection to other trees? Get rid of it now while the infection is only in one tree. It is much easier to manage fireblight if you do not have a source in the orchard. I saw fireblight literally destroy hundreds of acres of apple trees in 2000 here in SW Michigan. The industry still has not recovered from that epidemic. - Mark Longstroth SW Michigan District Fruit Educator Van Buren County MSU Extension Email - longs...@msu.edu http://web1.msue.msu.edu/vanburen/disthort.htm - -Original Message- From: apple-crop@virtualorchard.net [mailto:apple-c...@virtualorchard.net]on Behalf Of Axel Kratel Sent: Wednesday, June 17, 2009 12:19 AM To: Apple-Crop Subject: Apple-Crop: Fireblight on Ernst Bosch Dear all, I have an Ernst Bosch apple tree on MM111 that has developed a pretty bad case of fireblight. I have over 200 trees and I've never seen fireblight here before, so this is a first for me. Symptoms included the classic die back with the orange colored droplets. I've cut the infected wood, and applied serenade, and I've had to go back twice now to cut more. I've cut back quite far, yet the cuts are still turning orange. I disinfected sheers in between cuts. On the last cuts I've resorted to treating the cuts with hydrogen peroxide, but it seems hopeless. Any hope of saving the tree or should I sacrifice it? It's on it's fourth leaf. I am surprised that this variety is so susceptible. The literature claims it's not especially sensitive to fireblight. Thanks for your advice. I am willing to forgo organic to save a tree, so if there's any sort of systemic treatment that would be possible, I would consider it. Serenade is a good preventative, but it's too late for this tree.
RE: Apple-Crop: Fireblight on Ernst Bosch
Yank it out was a poor choice of words. Cut the tree down as soon as possible. The rootstock does not pose a threat right now, but the oozing tissues in the tree do. It is most likely that the fireblight came for an outside source and the bacteria were transported to the trees by bees or another pollinator. I have been looking at fireblight every year since I got this job and if the fireblight were systemic in the tree you probably would have seen the orange shoot tips on current seasons growth earlier in the trees life. I am convinced that sometimes fireblight comes in on the nursery stock occasionally, but if that was the case you probably would have seen these symptoms earlier, not a couple of year's down the line. I see older trees with fireblight that seems to come and go depending on the year and I am convinced that the bacteria is systemic in some older trees. It either has to be systemic or in the margin of active cankers to overwinter for us here in Michigan. A lot depends on how the bloom season goes. There are enough wild apple, crabapple and hawthorn trees about that they could easily maintain the population in overwintering cankers. This year in SW Michigan is instructive. We had relative warm weather just before bloom and a cool bloom period with three warm days in the middle of bloom. We run the Maryblyt model and the predicated bacteria population were only about 50% of what would have triggered and infection on these dates but the other 3 factors, Warm temperatures, wetting event, open blossoms were there. I did not recommend spraying because of the cool temperatures before and the cool temperatures forecast which actually came to be. We began to see blossom blight symptoms in older Jonathan trees about 2 weeks later, too late to have been caused by infection at the very beginning of bloom and too early to be caused by the warm weather we received at the end of bloom. The most likely scenario is that these infections occurred due to the proximity of some flowers to a source of bacteria, most like a canker near the blossom. One grower had not had fireblight in the orchard for several years and another had done an excellent job pruning it out during the winter. It is a frustrating disease that causes constant problems if you have it. I have more fireblight information posted on my website, including a sad picture of a systemic fruit infection on Rome taken Monday. - Mark Longstroth SW Michigan District Fruit Educator Van Buren County MSU Extension Email - longs...@msu.edu http://web1.msue.msu.edu/vanburen/disthort.htm - -Original Message- From: apple-crop@virtualorchard.net [mailto:apple-c...@virtualorchard.net]on Behalf Of Axel Kratel Sent: Thursday, June 18, 2009 12:19 PM To: Apple-Crop Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Mark, that sounds like good advice. Basically, I cut once, that didn't help. I cut again. if it comes back again I will yank out the tree. I do have a question for the group: When fireblight die back shows up as a result of flowers getting rained on, which of these two reasons would cause it: 1) Fireblight is systemic in the tree 2) Fireblight was brought to the tree from an outside vector. Thanks. -- From: Mark Longstroth longs...@msu.edu To: Apple-Crop apple-crop@virtualorchard.net Sent: Thursday, June 18, 2009 7:36:12 AM Subject: RE: Apple-Crop: Fireblight on Ernst Bosch Axel, If I had a 4 year old tree in an orchard of 200 trees with fireblight that bad, I would yank it out of the ground today! In my experience, 4 year old trees with that bad an infection don't survive. It sounds like the bacteria is running faster than you can cut and in my experience it will run very fast in wood back through three year old wood and in a 4 year old tree it is just a short jump to the rootstock. MM111 is rated as moderately resistant and I doubt it will survive with an infected susceptible scion such as you describe. If you inject strep into the tree you might save it or find out that you have a resistant strain in your orchard. Do you really want a source of fireblight in your orchard while you try to save one tree? What are you going to do if you have a storm which spreads the infection to other trees? Get rid of it now while the infection is only in one tree. It is much easier to manage fireblight if you do not have a source in the orchard. I saw fireblight literally destroy hundreds of acres of apple trees in 2000 here in SW Michigan. The industry still has not recovered from that epidemic. - Mark Longstroth SW Michigan District Fruit Educator Van Buren County MSU Extension Email - longs...@msu.edu http://web1.msue.msu.edu/vanburen/disthort.htm
RE: Apple-Crop: Fireblight on Ernst Bosch
Good Job Allen. I discussed that type of program Monday with a grower. Other sad fireblight tales. I had a grower who planted RubiJon this spring, which bloomed after normal and now have blossom blight. I suggested cutting back to 2 or 3 nodes above the graft union in an effort to save the rootstock (M26) on any tree that showed any symptoms. He also had a block of Idared on G30 which got fireblight in the fall (leaf hoppers?). He noticed 30 dead trees out of 150 this winter when he pruned but about half the planting has or is collapsing now and he will remove them all. - Mark Longstroth SW Michigan District Fruit Educator Van Buren County MSU Extension Email - longs...@msu.edu http://web1.msue.msu.edu/vanburen/disthort.htm - -Original Message- From: apple-crop@virtualorchard.net [mailto:apple-c...@virtualorchard.net]on Behalf Of Allen Teach - Sunrise Orchard Sent: Thursday, June 18, 2009 1:01 PM To: Apple-Crop Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Gentlemen: I certainly agree with Mark to get rid of the culprit tree yesterday. However, let me relay an experience we had last year. On a five acre block of 3rd leaf Honeycrisp on B9 and CG 16 (tall spindle) we had some blossom blight on very late rat tail bloom and began seeing sporadic shoot blight in late June. I immediately made ugly stub cuts on the affected branches, fired up the sprayer and applied Apogee to the entire block. I continued to patrol the block and reapplied the Apogee about 3 weeks later. this is totally unscientific but we were able to avoid a disaster. Granted Honeycrisp/B9-CG 16 is not extremely susceptible but we had the trees set up with water and fertilizer to grow vigorously. Allen Teach Sunrise Orchards Inc. Gays Mills, WI P.S. Let's all dodge the severe weather the next couple of days! - Original Message - From: Axel Kratel To: Apple-Crop Sent: Thursday, June 18, 2009 11:18 AM Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Mark, that sounds like good advice. Basically, I cut once, that didn't help. I cut again. if it comes back again I will yank out the tree. I do have a question for the group: When fireblight die back shows up as a result of flowers getting rained on, which of these two reasons would cause it: 1) Fireblight is systemic in the tree 2) Fireblight was brought to the tree from an outside vector. Thanks. From: Mark Longstroth longs...@msu.edu To: Apple-Crop apple-crop@virtualorchard.net Sent: Thursday, June 18, 2009 7:36:12 AM Subject: RE: Apple-Crop: Fireblight on Ernst Bosch Axel, If I had a 4 year old tree in an orchard of 200 trees with fireblight that bad, I would yank it out of the ground today! In my experience, 4 year old trees with that bad an infection don't survive. It sounds like the bacteria is running faster than you can cut and in my experience it will run very fast in wood back through three year old wood and in a 4 year old tree it is just a short jump to the rootstock. MM111 is rated as moderately resistant and I doubt it will survive with an infected susceptible scion such as you describe. If you inject strep into the tree you might save it or find out that you have a resistant strain in your orchard. Do you really want a source of fireblight in your orchard while you try to save one tree? What are you going to do if you have a storm which spreads the infection to other trees? Get rid of it now while the infection is only in one tree. It is much easier to manage fireblight if you do not have a source in the orchard. I saw fireblight literally destroy hundreds of acres of apple trees in 2000 here in SW Michigan. The industry still has not recovered from that epidemic. - Mark Longstroth SW Michigan District Fruit Educator Van Buren County MSU Extension Email - longs...@msu.edu http://web1.msue.msu.edu/vanburen/disthort.htm - -Original Message- From: apple-crop@virtualorchard.net [mailto:apple-c...@virtualorchard.net]on Behalf Of Axel Kratel Sent: Wednesday, June 17, 2009 12:19 AM To: Apple-Crop Subject: Apple-Crop: Fireblight on Ernst Bosch Dear all, I have an Ernst Bosch apple tree on MM111 that has developed a pretty bad case of fireblight. I have over 200 trees and I've never seen fireblight here before, so this is a first for me. Symptoms included the classic die back with the orange colored droplets. I've cut the infected wood, and applied serenade, and I've had to go back twice now to cut more. I've cut back quite far, yet the cuts are still turning orange. I disinfected sheers in between cuts
Re: Apple-Crop: Fireblight on Ernst Bosch
Fireblight - have you tried Fertilome's Streptomycin? From: Axel Kratel Sent: Wednesday, June 17, 2009 12:18 AM To: Apple-Crop Subject: Apple-Crop: Fireblight on Ernst Bosch Dear all, I have an Ernst Bosch apple tree on MM111 that has developed a pretty bad case of fireblight. I have over 200 trees and I've never seen fireblight here before, so this is a first for me. Symptoms included the classic die back with the orange colored droplets. I've cut the infected wood, and applied serenade, and I've had to go back twice now to cut more. I've cut back quite far, yet the cuts are still turning orange. I disinfected sheers in between cuts. On the last cuts I've resorted to treating the cuts with hydrogen peroxide, but it seems hopeless. Any hope of saving the tree or should I sacrifice it? It's on it's fourth leaf. I am surprised that this variety is so susceptible. The literature claims it's not especially sensitive to fireblight. Thanks for your advice. I am willing to forgo organic to save a tree, so if there's any sort of systemic treatment that would be possible, I would consider it. Serenade is a good preventative, but it's too late for this tree.
Re: Apple-Crop: Fireblight on Ernst Bosch
Axel You're in a tough place Alex. Bacterial diseases are generally tough, and in woody plants like apples, incredibly persistent. If you're cutting out infected material, I hope you're cutting back at least 6 from the infection. Any pest control material you use right now may be futile until conditions cease favoring disease. Just hold in there until warmer, drier weather prevails, then re-assess. I'm not familiar with the variety, but perhaps its not a good match for your climate. Good luck. Bill William H Shoemaker, UI-NRES Sr Research Specialist, Food Crops St Charles Horticulture Research Center 535 Randall Road St Charles, IL 60174 630-584-7254; FAX-584-4610 -- The 'Apple-Crop' LISTSERV is sponsored by the Virtual Orchard http://www.virtualorchard.net and managed by Win Cowgill and Jon Clements webmas...@virtualorchard.net. Apple-Crop is not moderated. Therefore, the statements do not represent official opinions and the Virtual Orchard takes no responsibility for the content.
Re: Apple-Crop: Fireblight on Ernst Bosch
We've had a very abnormal Spring. El Nino is kicking in, and as a result, we've had a number of low pressure systems drop south from the Gulf of Alaska that spin off the coast and suck in moisture out of the subtropics. Upwelling has ceased, and our water temperatures offshore are 15F higher than normal (normally 45F at the Farralone islands, currently at 60F) so overnight temps are unusually warm too (upper 50's as opposed to upper 40's.) This tree bloomed right during a week when conditions were ideal for fireblight - 1 week of fog/drizzle/rain at 65-75F. I've never seen this sort of thing before here as May is typically warm and dry. This Spring has been the worst as far as disease is concerned. I've cut off more than 6 inches away on each branch. My sense is that this variety is abnormally sensitive to fireblight. The question is, what happens to the bacteria when it gets warmer? Does it just go dormant in the tree? From: Bill Shoemaker wshoe...@illinois.edu To: Apple-Crop apple-crop@virtualorchard.net Sent: Wednesday, June 17, 2009 5:39:41 PM Subject: Re: Apple-Crop: Fireblight on Ernst Bosch Axel You're in a tough place Alex. Bacterial diseases are generally tough, and in woody plants like apples, incredibly persistent. If you're cutting out infected material, I hope you're cutting back at least 6 from the infection. Any pest control material you use right now may be futile until conditions cease favoring disease. Just hold in there until warmer, drier weather prevails, then re-assess. I'm not familiar with the variety, but perhaps its not a good match for your climate. Good luck. Bill William H Shoemaker, UI-NRES Sr Research Specialist, Food Crops St Charles Horticulture Research Center 535 Randall Road St Charles, IL 60174 630-584-7254; FAX-584-4610 -- The 'Apple-Crop' LISTSERV is sponsored by the Virtual Orchard http://www.virtualorchard.net and managed by Win Cowgill and Jon Clements webmas...@virtualorchard.net. Apple-Crop is not moderated. Therefore, the statements do not represent official opinions and the Virtual Orchard takes no responsibility for the content.
