Re: [apple-crop] Southwest Injury
Winter injury and south-west injury Click to print This disorder affects: Identification Buds Uneven or lack of bud break in the spring Brown or black dormant bud tissue compared to green tissue of healthy buds Scorching or drying of leaves Trunk Limbs Injury occurs in the lower trunk, crown or roots near the soil surface Large vertical cracks or splits on bark that may leak visible sap near the ground or snow line Development of suckers at base of the tree Damaged inner bark will turn brown, while healthy bark will appear greenish yellow Injury become more apparent during the growing season; as the cambium dies, flattened, dark coloured areas will be apparent on the damaged portion of the trunk Winter injury may cause tree death within one year. These trees may actually bloom and start to leaf out in the spring. Depending on the severity of the injury and the health of the tree the previous year, trees may die at any point during the first part of the growing season. Less severely injured trees may recover or they may decline for the next few years before dying. Bending, splitting or breaking of limbs due to heavy snow or ice load Often Confused With Rootstock-scion incompatibility bark tissue is discontinuous between rootstock and scion Girdling physical injury that prevents trunk growth Poor drainage (water stress) most severe in low-lying areas or where a tile is broken; puddling of water after rains Nutrient deficiencies confirm with tissue analysis Drought- follows hot dry weather Biology Frequency and severity of winter injury depend on a combination of planting site, tree species, tree health and ultimately the severity of the winter. Winter injury can be caused by a number of factors, including excessive winds (desiccate trees), bright sun or high mid-winter temperatures when ground is frozen, alternate freezing and thawing of ground in late winter, heavy snow and ice cause bending and may snap roots, ice damage to trunks and branches, and mammalian feeding. Buds and cambial tissue of fruit trees are the most sensitive to cold damage. Frequently, the damage is observed first in low-lying areas of the orchard or where natural airflow is restricted. Trees of low vitality, induced by poor cultural practices, inadequate insect pest and disease control, or heavy cropping are more susceptible to low temperature injury. Desiccation occurs when water leaves the plant faster than it is taken up. Other cell contituents, like sugars, become more concentrated within the cell during dormancy, also contributing to dehydration. In severely cold weather, the ground may freeze to a depth beyond the extent of the root system, cutting off the supply of water. If the previous fall had been dry, there may be insufficient ground moisture to supply roots with adequate water. The risk of desiccation is greatest during periods of strong winds or sunny weather. Freezing injury may occur when new growth is stimulated by late summer or early fall fertilization or pruning and may not have had time to harden off sufficiently to survive sudden drops to below freezing. Ice crystals form and rupture cell walls. This injury to the cells inhibits the movement of nutrients and water in the tree, causing damage, such as death of branch tips. If only some of the cells are killed, the tree will be able to survive in the spring when demands for water and nutrients are relatively low. In the summer, when such demands increase, the tree may show signs of delayed winter injury, because its damaged cells cannot move enough nutrients and water. Water may be plentiful at this time, but the plant will not be able to take it up as quickly as required. Symptoms of delayed injury include browning of leaves, flower and fruit loss. Freezing injury can also occur in the spring when sun or mild temperatures cause flower or leaf buds to break dormancy early. Freezing nights may kill these buds. Roots of cherries, peaches and nectarines are most susceptible to injury from soggy, wet soils. Pears, apples and plums are somewhat more tolerant but also can be injured by extended periods of wet soil conditions. Southwest injury, or winter sunscald, occurs in the winter in, peach, pear, cherry, plum and apricot. Injury is usually confined to the southwest sides of the trunk and main scaffold branches due to mid-afternoon sun exposure when temperature is often highest. Living cells just inside the outer bark (mostly phloem and cambium) are damaged by day to night temperature fluctuations during the winter months. Exposed bark warms up on sunny days and previously dormant cells within the tree become active in response to the warmth. These cells lose some of their cold-hardiness and are injured when temperatures drop below freezing during the night. Generally, as the tree matures, it develops thicker bark and becomes less susceptible to injury. However,
Re: [apple-crop] Southwest Injury
Greg: Growers who want to try to save some Southwest-Injured trees might want to consider sealing the tacked-down bark with Doc Farwell's Seal and Heal. I think the Doc Farwell's Grafting Seal is the same stuff. They form a very tough but flexible seal that can remain for years. The label recommends applying when temperature is 40F or higher. I tried to save a block of 12-year old high-grafted apple trees on Bud 118 six years ago, with disappointing results. Bark was tacked down with galvanized roofing nails before it had curled from drying, and Seal and Heal was painted on. Trees developed dead scaffolds on one or more sides on most of those that showed early, long bark cracks, and I have removed the block because it was not practical to maintain the scattered good trees. I don't recall having made an effort to de-fruit the injured trees in any of the years they were kept, but I think that suggestion of Dave Rosenberger's would be helpful. David Kollas Kollas Orchard, Connecticut On Mar 17, 2014, at 9:46 PM, Peck, Greg greg.p...@vt.edu wrote: Thanks to all those who responded to my email. Yes, for SWI (and most things in orchard systems), an ounce of prevention is worth a pound of cure. For those who missed it, there was a long discussion on trunk painting last year: http://www.mail-archive.com/apple-crop@virtualorchard.net/msg02242.html From reading all the responses, and considering the lack of tree availability for replanting this spring, it seems to me that it might be worth trying the salvage some of less damaged trunks by closing up the split bark. Debbie's rule-of-thumb sounds reasonable and would give growers some idea as to when to just move on. As Debbie also pointed out, the wounds could be an entry site for borers. The wound sites might also be a location for WAA colonies, which seem to have gotten worse under our BMSB-focused insecticide programs. I guess the exposed tissue could also be an entry point for herbicides. While bridge grafting is probably technically feasible, I'm getting the sense that it may not be worth the time. It's up to each grower to make that decision, but I'd be hesitant to say it's an economically feasible choice for large blocks of high-density trees unless you have a talented grafter on-staff. Greg Gregory Michael Peck, Ph.D. Assistant Professor of Horticulture Virginia Tech Alson H. Smith, Jr. Agricultural Research and Extension Center 595 Laurel Grove Road Winchester, VA 22602 USA 540/869-2560 ext 19 greg.p...@vt.edu arec.vaes.vt.edu/alson-h-smith www.anr.ext.vt.edu/tree-fruit/ blogs.ext.vt.edu/tree-fruit-horticulture www.facebook.com/VtechPomology ___ apple-crop mailing list apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop
Re: [apple-crop] Southwest Injury
Trees in Central Washington sustained a lot of trunk damage in November 2010, an event now called the Thanksgiving freeze. Daily high temperatures that had been 55 to 60 Fahrenheit (15C) dropped to as low as -5 to -18F (-23C). The trunks of many trees were not ready for this, so we saw a lot of discoloration under the bark the next spring. The most seriously injured trees showed symptoms the first spring, 2012, with bark splitting and peeling. Trees flowered, began to grow foliage and collapsed by the middle of summer. Many trees that were damaged did not die in 2012, but they were obviously suffering from the effects of the cold snap. I saw another wave of trees die in 2013 as the cold damaged trunks were attacked by secondary organisms, especially those that cause cankers. Perennial canker seems to be one of the most dangerous, as it continues to spread on the trunk when aggravated by woolly apple aphid. Last week I saw my most recent case of trees dying from the 2010 event, due to what I believe is perennial canker. This problem is widespread, it is a serious problem in some of the low spots and orchards that experienced temperatures even lower than those recorded by remote weather stations. Most of you have probably already experienced this sort of thing in the past. However, if you haven't, please be aware that you could lose trees for two or three more years if you have a winter severe enough to cause bark splitting on tree trunks. Tim Smith Regional Extension Specialist WSU -- Wenatchee Washington From: apple-crop-boun...@virtualorchard.net [mailto:apple-crop-boun...@virtualorchard.net] On Behalf Of Peck, Greg Sent: Monday, March 17, 2014 6:47 PM To: Apple-Crop Subject: Re: [apple-crop] Southwest Injury Thanks to all those who responded to my email. Yes, for SWI (and most things in orchard systems), an ounce of prevention is worth a pound of cure. For those who missed it, there was a long discussion on trunk painting last year: http://www.mail-archive.com/apple-crop@virtualorchard.net/msg02242.html From reading all the responses, and considering the lack of tree availability for replanting this spring, it seems to me that it might be worth trying the salvage some of less damaged trunks by closing up the split bark. Debbie's rule-of-thumb sounds reasonable and would give growers some idea as to when to just move on. As Debbie also pointed out, the wounds could be an entry site for borers. The wound sites might also be a location for WAA colonies, which seem to have gotten worse under our BMSB-focused insecticide programs. I guess the exposed tissue could also be an entry point for herbicides. While bridge grafting is probably technically feasible, I'm getting the sense that it may not be worth the time. It's up to each grower to make that decision, but I'd be hesitant to say it's an economically feasible choice for large blocks of high-density trees unless you have a talented grafter on-staff. Greg Gregory Michael Peck, Ph.D. Assistant Professor of Horticulture Virginia Tech Alson H. Smith, Jr. Agricultural Research and Extension Center 595 Laurel Grove Road Winchester, VA 22602 USA 540/869-2560 ext 19 greg.p...@vt.edumailto:greg.p...@vt.edu arec.vaes.vt.edu/alson-h-smith www.anr.ext.vt.edu/tree-fruit/http://www.anr.ext.vt.edu/tree-fruit/ blogs.ext.vt.edu/tree-fruit-horticulturehttp://blogs.ext.vt.edu/tree-fruit-horticulture www.facebook.com/VtechPomologyhttp://www.facebook.com/VtechPomology On Mar 17, 2014, at 10:05 AM, Deborah I. Breth d...@cornell.edumailto:d...@cornell.edu wrote: Greg, You could use the rule of thumb for canker surgery and if more than a 1/3 of the circumference is interrupted, likely nothing you can do. But if less than 1/3, try to cut the dead bark away using a straight linoleum cut so there is no shelter (under the split bark) that will attract and support the borers. The callus will be more uniform and heal that part of the trunk. There will always be the unknown with wood rotting fungi invading the exposed heart wood. Good luck. Deborah I. Breth Cornell Cooperative Extension - Lake Ontario Fruit Program Team Leader and IPM Specialist in Tree Fruit and Berries 12690 Rt. 31 Albion, NY 14411 mobile: 585.747.6039 phone: 585.798.4265 x 36 fax: 585.798.5191 email: d...@cornell.edumailto:d...@cornell.edu LOF website -Original Message- From: apple-crop-boun...@virtualorchard.netmailto:apple-crop-boun...@virtualorchard.net [mailto:apple-crop-boun...@virtualorchard.net] On Behalf Of kuffelcr...@kuffelcreek.commailto:kuffelcr...@kuffelcreek.com Sent: Sunday, March 16, 2014 12:30 PM To: Apple-crop discussion list Subject: Re: [apple-crop] Southwest Injury Greg; We get the same damage here in Southern California, but from sunburn, not Southwest Injury. But the damage is the same, dead cambium layer and sunken bark. Besides robbing vigor from the tree
Re: [apple-crop] Southwest Injury
Years ago we pruned some Red Del in December with similar injury that followed on larger trees. We stapled the bark tight on both sides and the trees recovered but with a permanent seam where the bark had split. The trees were about 12 in diameter. Art Kelly Kelly Orchards Acton, ME On Sun, Mar 16, 2014 at 10:42 AM, Peck, Greg greg.p...@vt.edu wrote: Apple-Crop participants, Like everyone else in the Eastern half of the US, we've had a particularly cold and snowy winter in Virginia. Not surprisingly, I am starting to hear reports about Southwest injury to young trees. While there is a lot of information available on how to prevent southwest injury, I have not been able to find much information on how to deal with the trunks after the damage has been done. Typically, growers in Virginia have do not paint trunks with latex paint, but many will probably reconsider that decision in future years. Many trees are probably not going to make it, but I'm wondering if anyone has experience trying to save some of the less severely injured trees with bridge-grafts. How about wrapping the bark with grafting tape to try to get the wounds to heal? (I'm guessing that this will have a low success rate because the tissue has already dried out.) Depending upon how far into the rootstock the split extends and the age of the tree, we might also try cutting off the scion and hoping an advantageous bud breaks dormancy. Any other suggestions from those who have to deal with Southwest Injury on a more annual basis? Thanks, Greg Gregory Michael Peck, Ph.D. Assistant Professor of Horticulture Virginia Tech Alson H. Smith, Jr. Agricultural Research and Extension Center 595 Laurel Grove Road Winchester, VA 22602 USA 540/869-2560 ext 19 greg.p...@vt.edu arec.vaes.vt.edu/alson-h-smith www.anr.ext.vt.edu/tree-fruit/ blogs.ext.vt.edu/tree-fruit-horticulture www.facebook.com/VtechPomology ___ apple-crop mailing list apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop -- Art Kelly Kelly Orchards Acton, ME ___ apple-crop mailing list apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop
Re: [apple-crop] Southwest Injury
Greg, You could use the rule of thumb for canker surgery and if more than a 1/3 of the circumference is interrupted, likely nothing you can do. But if less than 1/3, try to cut the dead bark away using a straight linoleum cut so there is no shelter (under the split bark) that will attract and support the borers. The callus will be more uniform and heal that part of the trunk. There will always be the unknown with wood rotting fungi invading the exposed heart wood. Good luck. Deborah I. Breth Cornell Cooperative Extension - Lake Ontario Fruit Program Team Leader and IPM Specialist in Tree Fruit and Berries 12690 Rt. 31 Albion, NY 14411 mobile: 585.747.6039 phone: 585.798.4265 x 36 fax: 585.798.5191 email: d...@cornell.edu LOF website -Original Message- From: apple-crop-boun...@virtualorchard.net [mailto:apple-crop-boun...@virtualorchard.net] On Behalf Of kuffelcr...@kuffelcreek.com Sent: Sunday, March 16, 2014 12:30 PM To: Apple-crop discussion list Subject: Re: [apple-crop] Southwest Injury Greg; We get the same damage here in Southern California, but from sunburn, not Southwest Injury. But the damage is the same, dead cambium layer and sunken bark. Besides robbing vigor from the tree, here it also attracts borers who take advantage of the tree's inability to sap out the maggot, and exploit the edges of the injury. The wounds will not heal; they may eventually be covered by cambium growing from either side, like a pruning stump is covered over. Bridge grafting is easier on shorter injuries like vole and rabbit damage; the problem with SWI is that the wounds are long and narrow. Cutting the tree off and letting a latent bud sprout may be a viable option depending on the damage, but you will have to weigh the loss of productivity against how long it would take if you just pruned the tree hard and let it try to heal the SWI. Painting trunks white, especially with an airless sprayer, seems way less trouble than any of this. Kevin Hauser Kuffel Creek Apple Nursery Riverside, California Nakifuma, Uganda, East Africa On Sun, 16 Mar 2014 10:42:00 -0400, Peck, Greg greg.p...@vt.edu wrote: Apple-Crop participants, Like everyone else in the Eastern half of the US, we've had a particularly cold and snowy winter in Virginia. Not surprisingly, I am starting to hear reports about Southwest injury to young trees. While there is a lot of information available on how to prevent southwest injury, I have not been able to find much information on how to deal with the trunks after the damage has been done. Typically, growers in Virginia have do not paint trunks with latex paint, but many will probably reconsider that decision in future years. Many trees are probably not going to make it, but I'm wondering if anyone has experience trying to save some of the less severely injured trees with bridge-grafts. How about wrapping the bark with grafting tape to try to get the wounds to heal? (I'm guessing that this will have a low success rate because the tissue has already dried out.) Depending upon how far into the rootstock the split extends and the age of the tree, we might also try cutting off the scion and hoping an advantageous bud breaks dormancy. Any other suggestions from those who have to deal with Southwest Injury on a more annual basis? Thanks, Greg Gregory Michael Peck, Ph.D. Assistant Professor of Horticulture Virginia Tech Alson H. Smith, Jr. Agricultural Research and Extension Center 595 Laurel Grove Road Winchester, VA 22602 USA 540/869-2560 ext 19 greg.p...@vt.edumailto:greg.p...@vt.edu arec.vaes.vt.edu/alson-h-smith www.anr.ext.vt.edu/tree-fruit/http://www.anr.ext.vt.edu/tree-fruit/ blogs.ext.vt.edu/tree-fruit-horticulturehttp://blogs.ext.vt.edu/tree-fruit-horticulture www.facebook.com/VtechPomologyhttp://www.facebook.com/VtechPomology ___ apple-crop mailing list apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop ___ apple-crop mailing list apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop
Re: [apple-crop] Southwest Injury
I would think apples and pears have a better chance of recovering than peaches or other tender fruit. It depends on how deep the split goes as well. In severe cold I have seen trees split deep into the heartwood, but its more common to see the only the bark to the cambium. Before trunk painting became commonplace (as well as milder winters), we used to tack the bark down - which excludes some insects and diseases. I was always surprised to see how much the split was able to join together. With some good TLC this season, the tree will be set back but can heal quite well. At one time, we used to say trees need to be 5+ years, but with nursery trees in short supply, it might be worthwhile to try to save younger trees. As Dave says, if you plan on grafting, the wood needs to be collected and stored soon. Don't throw it in an apple storage - ethylene is very damaging. Also, the grafting wax is very important to get a good seal. I'm not sure what is available on the market, so you should source that now too. Here are some old factsheets we have on grafting and repairs. Funny that we were musing if these are worth keeping :) Orchard Grafting Methods http://www.omafra.gov.on.ca/english/crops/facts/98-005.htm Repair Grafting http://www.omafra.gov.on.ca/english/crops/facts/98-003.htm I'm also wondering how much vole damage we will see when the snow melts. Leslie [cid:image001.gif@01CDC8A7.C95AB0F0] Leslie Huffman 519-738-1256 leslie.huff...@ontario.camailto:519-738-1256leslie.huff...@ontario.ca From: apple-crop-boun...@virtualorchard.net [mailto:apple-crop-boun...@virtualorchard.net] On Behalf Of David A. Rosenberger Sent: March-16-14 10:48 PM To: Apple-crop discussion list Subject: Re: [apple-crop] Southwest Injury Hi, Greg - I'm really curious to hear what others suggest. Old-timers in northern NY would sometimes use shingle nails to nail the loose bark back to the trunks of big old winter-injured trees when the bark split away from the trunks due to cold injury during winter. I'm not certain if it did any good, but it might have helped to reduce further desiccation of the loose bark if it was not already killed all the way back to the point of attachment. Obviously, there is no value in nailing back dead bark. So long as there is still live bark on one side of the trees, you might be surprised to see how well the trees recover on their own if you can avoid crop load stress and drought stress for the next year. The damaged trees will never be quite the same, but my bet is that those trees that are not completely girdled will recover if they can be defruited or at least over-thinned this year. Concerning bridge grafting, it's pretty labor intensive, but I've seen it used effectively. Unless you have ideally placed root suckers already growing at the base of affected trees, you would need to gather the grafting wood immediately and refrigerate it so as to have dormant wood for grafting when the bark begins to slip a bit later in spring. Grafting will be more feasible if you had enough snow cover to keep some bark alive above the soil line. If bark is killed all the way to the soil line, you might instead consider inarch grafting with rootstock liners (if you can find any for spring delivery). These can be inserted next to the trunks with a needle-nose spade, stomped to backfill the spade slot, and grafted into the trunks above the damaged area sometime near petal fall after the liners have begun to grow. We did this successfully with some Delicious/MM.106 trees that were dying from union necrosis (ToRSV) back in the early 80s. In that case, we needed several liners/tree because the union was dying all the way around the tree. A single liner/tree might work OK if you still have live bark on one side. But as noted above, the tree may recover on its own if it is still alive on one side. As noted above, grafting is labor intensive, especially if it will be required for many trees/A as in high-density plantings. In addition to the labor required for grafting, additional attention is required to remove buds that will sprout on the inarch pieces and special care will be required to avoid hitting those tender graft pieces when applying contact herbicides. On Mar 16, 2014, at 10:42 AM, Peck, Greg greg.p...@vt.edumailto:greg.p...@vt.edu wrote: Apple-Crop participants, Like everyone else in the Eastern half of the US, we've had a particularly cold and snowy winter in Virginia. Not surprisingly, I am starting to hear reports about Southwest injury to young trees. While there is a lot of information available on how to prevent southwest injury, I have not been able to find much information on how to deal with the trunks after the damage has been done. Typically, growers in Virginia have do not paint trunks with latex paint, but many will probably reconsider that decision in future years. Many trees are probably not going to make it, but I'm
Re: [apple-crop] Southwest Injury
Thanks to all those who responded to my email. Yes, for SWI (and most things in orchard systems), an ounce of prevention is worth a pound of cure. For those who missed it, there was a long discussion on trunk painting last year: http://www.mail-archive.com/apple-crop@virtualorchard.net/msg02242.html From reading all the responses, and considering the lack of tree availability for replanting this spring, it seems to me that it might be worth trying the salvage some of less damaged trunks by closing up the split bark. Debbie's rule-of-thumb sounds reasonable and would give growers some idea as to when to just move on. As Debbie also pointed out, the wounds could be an entry site for borers. The wound sites might also be a location for WAA colonies, which seem to have gotten worse under our BMSB-focused insecticide programs. I guess the exposed tissue could also be an entry point for herbicides. While bridge grafting is probably technically feasible, I'm getting the sense that it may not be worth the time. It's up to each grower to make that decision, but I'd be hesitant to say it's an economically feasible choice for large blocks of high-density trees unless you have a talented grafter on-staff. Greg Gregory Michael Peck, Ph.D. Assistant Professor of Horticulture Virginia Tech Alson H. Smith, Jr. Agricultural Research and Extension Center 595 Laurel Grove Road Winchester, VA 22602 USA 540/869-2560 ext 19 greg.p...@vt.edumailto:greg.p...@vt.edu arec.vaes.vt.edu/alson-h-smith www.anr.ext.vt.edu/tree-fruit/http://www.anr.ext.vt.edu/tree-fruit/ blogs.ext.vt.edu/tree-fruit-horticulturehttp://blogs.ext.vt.edu/tree-fruit-horticulture www.facebook.com/VtechPomologyhttp://www.facebook.com/VtechPomology On Mar 17, 2014, at 10:05 AM, Deborah I. Breth d...@cornell.edumailto:d...@cornell.edu wrote: Greg, You could use the rule of thumb for canker surgery and if more than a 1/3 of the circumference is interrupted, likely nothing you can do. But if less than 1/3, try to cut the dead bark away using a straight linoleum cut so there is no shelter (under the split bark) that will attract and support the borers. The callus will be more uniform and heal that part of the trunk. There will always be the unknown with wood rotting fungi invading the exposed heart wood. Good luck. Deborah I. Breth Cornell Cooperative Extension - Lake Ontario Fruit Program Team Leader and IPM Specialist in Tree Fruit and Berries 12690 Rt. 31 Albion, NY 14411 mobile: 585.747.6039 phone: 585.798.4265 x 36 fax: 585.798.5191 email: d...@cornell.edumailto:d...@cornell.edu LOF website -Original Message- From: apple-crop-boun...@virtualorchard.netmailto:apple-crop-boun...@virtualorchard.net [mailto:apple-crop-boun...@virtualorchard.net] On Behalf Of kuffelcr...@kuffelcreek.commailto:kuffelcr...@kuffelcreek.com Sent: Sunday, March 16, 2014 12:30 PM To: Apple-crop discussion list Subject: Re: [apple-crop] Southwest Injury Greg; We get the same damage here in Southern California, but from sunburn, not Southwest Injury. But the damage is the same, dead cambium layer and sunken bark. Besides robbing vigor from the tree, here it also attracts borers who take advantage of the tree's inability to sap out the maggot, and exploit the edges of the injury. The wounds will not heal; they may eventually be covered by cambium growing from either side, like a pruning stump is covered over. Bridge grafting is easier on shorter injuries like vole and rabbit damage; the problem with SWI is that the wounds are long and narrow. Cutting the tree off and letting a latent bud sprout may be a viable option depending on the damage, but you will have to weigh the loss of productivity against how long it would take if you just pruned the tree hard and let it try to heal the SWI. Painting trunks white, especially with an airless sprayer, seems way less trouble than any of this. Kevin Hauser Kuffel Creek Apple Nursery Riverside, California Nakifuma, Uganda, East Africa On Sun, 16 Mar 2014 10:42:00 -0400, Peck, Greg greg.p...@vt.edumailto:greg.p...@vt.edu wrote: Apple-Crop participants, Like everyone else in the Eastern half of the US, we've had a particularly cold and snowy winter in Virginia. Not surprisingly, I am starting to hear reports about Southwest injury to young trees. While there is a lot of information available on how to prevent southwest injury, I have not been able to find much information on how to deal with the trunks after the damage has been done. Typically, growers in Virginia have do not paint trunks with latex paint, but many will probably reconsider that decision in future years. Many trees are probably not going to make it, but I'm wondering if anyone has experience trying to save some of the less severely injured trees with bridge-grafts. How about wrapping the bark with grafting tape to try to get the wounds to heal? (I'm guessing
Re: [apple-crop] Southwest Injury
Greg; We get the same damage here in Southern California, but from sunburn, not Southwest Injury. But the damage is the same, dead cambium layer and sunken bark. Besides robbing vigor from the tree, here it also attracts borers who take advantage of the tree's inability to sap out the maggot, and exploit the edges of the injury. The wounds will not heal; they may eventually be covered by cambium growing from either side, like a pruning stump is covered over. Bridge grafting is easier on shorter injuries like vole and rabbit damage; the problem with SWI is that the wounds are long and narrow. Cutting the tree off and letting a latent bud sprout may be a viable option depending on the damage, but you will have to weigh the loss of productivity against how long it would take if you just pruned the tree hard and let it try to heal the SWI. Painting trunks white, especially with an airless sprayer, seems way less trouble than any of this. Kevin Hauser Kuffel Creek Apple Nursery Riverside, California Nakifuma, Uganda, East Africa On Sun, 16 Mar 2014 10:42:00 -0400, Peck, Greg greg.p...@vt.edu wrote: Apple-Crop participants, Like everyone else in the Eastern half of the US, we've had a particularly cold and snowy winter in Virginia. Not surprisingly, I am starting to hear reports about Southwest injury to young trees. While there is a lot of information available on how to prevent southwest injury, I have not been able to find much information on how to deal with the trunks after the damage has been done. Typically, growers in Virginia have do not paint trunks with latex paint, but many will probably reconsider that decision in future years. Many trees are probably not going to make it, but I'm wondering if anyone has experience trying to save some of the less severely injured trees with bridge-grafts. How about wrapping the bark with grafting tape to try to get the wounds to heal? (I'm guessing that this will have a low success rate because the tissue has already dried out.) Depending upon how far into the rootstock the split extends and the age of the tree, we might also try cutting off the scion and hoping an advantageous bud breaks dormancy. Any other suggestions from those who have to deal with Southwest Injury on a more annual basis? Thanks, Greg Gregory Michael Peck, Ph.D. Assistant Professor of Horticulture Virginia Tech Alson H. Smith, Jr. Agricultural Research and Extension Center 595 Laurel Grove Road Winchester, VA 22602 USA 540/869-2560 ext 19 greg.p...@vt.edumailto:greg.p...@vt.edu arec.vaes.vt.edu/alson-h-smith www.anr.ext.vt.edu/tree-fruit/http://www.anr.ext.vt.edu/tree-fruit/ blogs.ext.vt.edu/tree-fruit-horticulturehttp://blogs.ext.vt.edu/tree-fruit-horticulture www.facebook.com/VtechPomologyhttp://www.facebook.com/VtechPomology ___ apple-crop mailing list apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop
Re: [apple-crop] Southwest Injury
Greg, My gut tells me grafting tape will not help. I think an open wound will heal better. I suppose the SW side thawed and quickly refroze. Somewhere I have seen adhesive backed insulation that has a peel-off coating. If this were white and had UV protection, strips a few inches wide and a foot or two long could be stuck to the south -southwest side of trees to prevent this from happening. As far as bridge grafting, this is beyond me. Seems like a replant would be cheaper/faster, I don't know. I paint newly planted trees with a cheap 2 gallon hand pump sprayer. 3 or 4 to 1 paint with water, and I can spray 1000 trees in 3-4 hours. I walk the rows on the S.E. side and then the S.W. side. I use the Ace Hardware sprayer on sale for $9.99 (reg 12.99) and just toss the sprayer after the job is done. Hugh Thomas Stevensville, MT On Sun, Mar 16, 2014 at 9:30 AM, kuffelcr...@kuffelcreek.com wrote: Greg; We get the same damage here in Southern California, but from sunburn, not Southwest Injury. But the damage is the same, dead cambium layer and sunken bark. Besides robbing vigor from the tree, here it also attracts borers who take advantage of the tree's inability to sap out the maggot, and exploit the edges of the injury. The wounds will not heal; they may eventually be covered by cambium growing from either side, like a pruning stump is covered over. Bridge grafting is easier on shorter injuries like vole and rabbit damage; the problem with SWI is that the wounds are long and narrow. Cutting the tree off and letting a latent bud sprout may be a viable option depending on the damage, but you will have to weigh the loss of productivity against how long it would take if you just pruned the tree hard and let it try to heal the SWI. Painting trunks white, especially with an airless sprayer, seems way less trouble than any of this. Kevin Hauser Kuffel Creek Apple Nursery Riverside, California Nakifuma, Uganda, East Africa On Sun, 16 Mar 2014 10:42:00 -0400, Peck, Greg greg.p...@vt.edu wrote: Apple-Crop participants, Like everyone else in the Eastern half of the US, we've had a particularly cold and snowy winter in Virginia. Not surprisingly, I am starting to hear reports about Southwest injury to young trees. While there is a lot of information available on how to prevent southwest injury, I have not been able to find much information on how to deal with the trunks after the damage has been done. Typically, growers in Virginia have do not paint trunks with latex paint, but many will probably reconsider that decision in future years. Many trees are probably not going to make it, but I'm wondering if anyone has experience trying to save some of the less severely injured trees with bridge-grafts. How about wrapping the bark with grafting tape to try to get the wounds to heal? (I'm guessing that this will have a low success rate because the tissue has already dried out.) Depending upon how far into the rootstock the split extends and the age of the tree, we might also try cutting off the scion and hoping an advantageous bud breaks dormancy. Any other suggestions from those who have to deal with Southwest Injury on a more annual basis? Thanks, Greg Gregory Michael Peck, Ph.D. Assistant Professor of Horticulture Virginia Tech Alson H. Smith, Jr. Agricultural Research and Extension Center 595 Laurel Grove Road Winchester, VA 22602 USA 540/869-2560 ext 19 greg.p...@vt.edumailto:greg.p...@vt.edu arec.vaes.vt.edu/alson-h-smith www.anr.ext.vt.edu/tree-fruit/http://www.anr.ext.vt.edu/tree-fruit/ blogs.ext.vt.edu/tree-fruit-horticulture http://blogs.ext.vt.edu/tree-fruit-horticulture www.facebook.com/VtechPomologyhttp://www.facebook.com/VtechPomology ___ apple-crop mailing list apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop ___ apple-crop mailing list apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop
Re: [apple-crop] Southwest Injury
Hi, Greg — I’m really curious to hear what others suggest. Old-timers in northern NY would sometimes use shingle nails to nail the loose bark back to the trunks of big old winter-injured trees when the bark split away from the trunks due to cold injury during winter. I’m not certain if it did any good, but it might have helped to reduce further desiccation of the loose bark if it was not already killed all the way back to the point of attachment. Obviously, there is no value in nailing back dead bark. So long as there is still live bark on one side of the trees, you might be surprised to see how well the trees recover on their own if you can avoid crop load stress and drought stress for the next year. The damaged trees will never be quite the same, but my bet is that those trees that are not completely girdled will recover if they can be defruited or at least over-thinned this year. Concerning bridge grafting, it’s pretty labor intensive, but I’ve seen it used effectively. Unless you have ideally placed root suckers already growing at the base of affected trees, you would need to gather the grafting wood immediately and refrigerate it so as to have dormant wood for grafting when the bark begins to slip a bit later in spring. Grafting will be more feasible if you had enough snow cover to keep some bark alive above the soil line. If bark is killed all the way to the soil line, you might instead consider inarch grafting with rootstock liners (if you can find any for spring delivery). These can be inserted next to the trunks with a needle-nose spade, stomped to backfill the spade slot, and grafted into the trunks above the damaged area sometime near petal fall after the liners have begun to grow. We did this successfully with some Delicious/MM.106 trees that were dying from union necrosis (ToRSV) back in the early 80s. In that case, we needed several liners/tree because the union was dying all the way around the tree. A single liner/tree might work OK if you still have live bark on one side. But as noted above, the tree may recover on its own if it is still alive on one side. As noted above, grafting is labor intensive, especially if it will be required for many trees/A as in high-density plantings. In addition to the labor required for grafting, additional attention is required to remove buds that will sprout on the inarch pieces and special care will be required to avoid hitting those tender graft pieces when applying contact herbicides. On Mar 16, 2014, at 10:42 AM, Peck, Greg greg.p...@vt.edumailto:greg.p...@vt.edu wrote: Apple-Crop participants, Like everyone else in the Eastern half of the US, we've had a particularly cold and snowy winter in Virginia. Not surprisingly, I am starting to hear reports about Southwest injury to young trees. While there is a lot of information available on how to prevent southwest injury, I have not been able to find much information on how to deal with the trunks after the damage has been done. Typically, growers in Virginia have do not paint trunks with latex paint, but many will probably reconsider that decision in future years. Many trees are probably not going to make it, but I'm wondering if anyone has experience trying to save some of the less severely injured trees with bridge-grafts. How about wrapping the bark with grafting tape to try to get the wounds to heal? (I'm guessing that this will have a low success rate because the tissue has already dried out.) Depending upon how far into the rootstock the split extends and the age of the tree, we might also try cutting off the scion and hoping an advantageous bud breaks dormancy. Any other suggestions from those who have to deal with Southwest Injury on a more annual basis? Thanks, Greg Gregory Michael Peck, Ph.D. Assistant Professor of Horticulture Virginia Tech Alson H. Smith, Jr. Agricultural Research and Extension Center 595 Laurel Grove Road Winchester, VA 22602 USA 540/869-2560 ext 19 greg.p...@vt.edumailto:greg.p...@vt.edu arec.vaes.vt.edu/alson-h-smithhttp://arec.vaes.vt.edu/alson-h-smith www.anr.ext.vt.edu/tree-fruit/http://www.anr.ext.vt.edu/tree-fruit/ blogs.ext.vt.edu/tree-fruit-horticulturehttp://blogs.ext.vt.edu/tree-fruit-horticulture www.facebook.com/VtechPomologyhttp://www.facebook.com/VtechPomology photo.JPG photo.JPG ___ apple-crop mailing list apple-crop@virtualorchard.netmailto:apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop ___ apple-crop mailing list apple-crop@virtualorchard.net http://virtualorchard.net/mailman/listinfo/apple-crop
