Editing Fire blight (section)

==Dissemination==
[[Image:Severe fire blight infection on apples.jpg|thumb|Gala [[apple]] branch with “scorched” leaves after a severe fire blight infection.]]
''Erwinia amylovora'' overwinters in cankers formed during the previous season. In the spring warmer  temperatures support development and bacteria-filled ooze begins to exude from the cankers.<ref>{{cite book |last1=van der Zwet |first1=Tom |last2=Keil |first2=Harry L |title=Fire Blight: a bacterial disease of rosaceous plants |date=1979 |pages=200 : ill. (some col.) maps. –- |publisher=U.S. Department of Agriculture |oclc=256060652 |url=http://handle.nal.usda.gov/10113/CAT79714375}}{{page needed|date=July 2021}}</ref> The factors that determine whether or not cankers become active are not well known, but it is thought that cankers found on larger or older tree limbs are more likely to become active.<ref name="Beer">{{cite journal |last1=Beer |first1=Steven V. |last2=Norelli |first2=John L. |title=Fire Blight Epidemiology: Factors Affecting Release of ''Erwinia Amylovora'' by Cankers |journal=Phytopathology |volume=77 |issue=9 |year=1977 |pages=1119–1125 |doi=10.1094/Phyto-67-1119}}</ref> [[Honeybee]]s and other [[insect]]s are attracted to this ooze and can spread bacteria to susceptible tissue, such as [[flower stigma]]ta.<ref>{{cite journal |last1=Thomson |first1=S. V. |title=The role of the stigma in fire blight infections |journal=[[Phytopathology (journal)|Phytopathology]] |date=1986 |volume=76 |issue=5 |pages=476–482 |doi=10.1094/Phyto-76-476}}</ref> [[Bird]]s, [[rain]] and [[wind]] can also transmit the bacterium to susceptible tissue, the colonisation of which will be heavily decided by temperature (21-27 C is most favourable) and moisture either from rain or heavy dew. Bacterial procession into the [[nectary|nectaries]] {{endash}} cause "blossom blight". Flowers one to three days old are more [[Plant disease resistance|susceptible]] than those five to eight days old. See Curry 1987 for the source and further review of this subject.<ref name="Malnoy-et-al-2012">{{cite journal |last1=Malnoy |first1=Mickael |last2=Martens |first2=Stefan |last3=Norelli |first3=John L. |last4=Barny |first4=Marie-Anne |last5=Sundin |first5=George W. |last6=Smits |first6=Theo H.M. |last7=Duffy |first7=Brion |title=Fire Blight: Applied Genomic Insights of the Pathogen and Host |journal=[[Annual Review of Phytopathology]] |publisher=[[Annual Reviews (publisher)|Annual Reviews]] |volume=50 |issue=1 |date=2012-09-08 |issn=0066-4286 |doi=10.1146/annurev-phyto-081211-172931 |pages=475–494|pmid=22702352 }}</ref>

Other than through the flowers, the bacterium can enter the plant through the stomata. Also highly susceptible to infection are lesions such as punctures caused by plant-sucking insects and tears caused by a variety of means, including infected cultivating tools. A few minutes of heavy hail can spread the disease throughout an entire orchard and growers normally do not wait until symptoms appear but begin control measures{{Citation needed|date=June 2021|reason=Please cite at least one of the aforementioned measures since there are next to none (bacteriophage-based control is still into research phase and far from being mature) considered to be  effective.}} within a few hours.{{citation needed|date=November 2022}}

Once the bacterium gains access to the xylem or cortical parenchyma of the plant, it causes blackened, necrotic [[lesion]]s, which may also produce a viscous [[exudate]]. This bacteria-laden exudate can be distributed to other parts of the same plant or to susceptible areas of different plants by rain, birds or insects, causing secondary [[infection]]s. The disease spreads most quickly during hot, wet [[weather]] and is dormant in the winter when temperatures drop.{{citation needed|date=November 2022}}

The pathogen spreads through the tree from the point of infection via the plant's [[Vascular tissue|vascular]] system, eventually reaching the [[root]]s and/or [[grafting|graft]] junction of the plant. Once the plant's roots are affected, the death of the plant often results. Over-pruning and too much  fertilization (especially with [[nitrogen]]) can lead to [[water sprout]] and other midsummer growth that leave the tree more susceptible.{{citation needed|date=November 2022}}

Unfortunately, while chemicals and meticulous pruning can keep an infected tree productive, there is no known comprehensive cure for fire blight; the best that can be done is to prevent its spread by measures such as avoidance of overhead water systems, as falling water can spread the disease and the  careful pruning of tainted stems or branches. Great attention must be paid to any gardening tools that have been exposed to the causitive microorganisms. These tools should be disinfected in an alcohol solution containing three parts [[denatured alcohol]] to one part water. Diluted household bleach (one part bleach to nine parts water) can likewise be utilized. Of course, implements should afterwards be dried and oiled to forestall corrosion.<ref>{{Cite web|url=https://www.gardeningknowhow.com/plant-problems/disease/fire-blight-remedies-and-symptoms.htm |title=StackPath|date=26 July 2021 }}</ref>

The fly ''[[Delia platura]]'' has been observed visiting fire blight wounds to feed and can successfully transmit fire blight to already damaged apple shoots.<ref name="Boucher-et-al-2020" /> Fire blight exopolysaccharide also served as the adhesive to attach propagated cells to ''D. platura''.<ref name="Boucher-et-al-2020" /> ''D. platura'' shed fire blight at a constant rate<ref name="Boucher-et-al-2020" /> - and did not suffer from doing so - for at least five days.<ref name="Boucher-et-al-2020" />