A Minor Massacre Bleeding canker in Aesculus hippocastanum
ÂŠ Jessica Worden 2011
esculus hippocastanum, a native to south eastern Europe, found its way to northern Europe at the beginning of the 17th century. Other variants of the tree, such as Aesculus indica and the hybrid Aesculus x carnea, were introduced to Britain in the 19th century. The Aesculus hippocastanum suffers from a variety of horticultural ailments, caused by bacteria, fungi or pests. (A pair of jeans, a T-shirt with a forgettable logo. Peach, black boots.) The brown blotches on horse chestnut leaves are a common sight, caused by the fungus Guignardia aesculi. They are unsightly but relatively harmless. Bleeding canker, however, which was historically caused by the Phytophthora fungus, has proved a serious tree blight in the past decade. Previously the number of occurrences of bleeding canker in Aesculus hippocastanum trees was relatively small. (There are two characters, a man and a woman. It could be a date or just two friends meeting.) 1
The first signs of infection are: a reddish, tarry liquid, oozing from fast growing lesions on the trunk. (She tries to move away.) As the outer bark is compromised the inner layer of cambium dies off. Rot girdles the trunk. The rest of the tree rapidly succumbs as it is cut off from nutrients and oxygen. (He hits her several times in the face.) In 2003 the incidence of bleeding canker in western European horse chestnut trees rose dramatically.1 Subsequent studies of diseased tissues determined that the bacteria Pseudomonas syringae, not the fungus Phytophthora, was responsible for the widespread recent emergence of bleeding canker in A hippocastanum populations.2 They are walking along the street and pass through Trafalgar Square, heading towards Hyde Park. They are going for a picnic or just to sit in the shade on a warm spring day. When they sit down they talk for a bit and then become amorous. They kiss. She lies back on the grass.
This pathogen was first isolated in 1980 by JC 1. JF Webber, NM Parkinson, J Rose1, H Stanford Cook and JG Elphinstone, 2007, “Isolation and Identification of Pseudomonas Syringae pv Aesculi Causing Bleeding Canker of Horse Chestnut in the UK”, New Disease Reports 15, p58. 2. Ibid. 2
urgapal and B Singh3 in the foliage of the Aesculus D Indica. (I was..., he did...I mean...I had told him I did want to...that I didn’t like it in public.) (His hand moves underneath her skirt4). It was later found in 2005 on an A Indica specimen in Surrey suffering from leaf spot symptoms. The fumbling intent of his hands is not clear; she tries to move away. He hits her several times in the face and then goes back to fumbling. This goes on for an indeterminate amount of time. He sits up and moves away. She uses a tissue from her bag to wipe her face. Then they get up and leave. When they sit down, they talk and he moves closer. They kiss. His hand moves underneath her skirt. He pushes her back on the grass. He makes a fist in her hair, close to the scalp and jerks her head to one side. He hits her several times in 3. JC Durgapal and B Singh, 1980, “Taxonomy of Pseudomonads Pathogenic to Horse Chestnut, Wild Fig and Wild Cherry in India”, Indian Phytopathology 33, pp533-535. 4. It is a short dress in a dark blue acrylic fabric with large white dots, sewn on the bias. The label reads: Marks & Spencer, size 8, dry clean only. The cut is conservative, sleeveless with a high round neck and knee-length. It has been altered, cut to mid-thigh, and hangs loosely. The fabric could be described as silky, although it does not shine as some silk does nor does it slide over the skin exactly as silk does. 4
the face. She tries to move away. His hand is up her skirt. This goes on. Then he sits up and repositions his crotch near her face. He moves away and she uses tissues from her large black bag to wipe her face. They get up and
The Phytophthora genus had been the leading cause of canker symptoms among trees, (leave.) causing blight and root-rot in both Europe and the Americas since the 1950s. It is a member of a family of oomcytes responsible for many destructive and often fatal horticultural diseases. For example, it houses the pathogen that caused the Great Irish Famine (1845-1849) and continues to plague potato crops today. Currently it is the causal agent in only 5-10% of all A hippocastanum trees suffering from cankers in the UK.5 His hands are rummaging near her crotch. They are unclear, and she tries to move away. This goes on for an indeterminate amount of time. Then they get up and leave. When they sit down they talk for a bit and he moves closer. They kiss. His hand moves underneath her skirt. He pushes her back on the grass. 5. “Symptoms and Causal Agent of Bleeding Canker of Horse Chestnut”, UK Forestry Commission, http://www.forestresearch. gov.uk/website/forestresearch.nsf/ByUnique/INFD-6KYBSS, retrieved 2010-07-09. 6
1. Symptoms of bleeding canker
She takes off her shoes. The black fabric of her tights shows pills near the soles and there is a small snag on the right thigh, the elastic nylon pulled out to form a small tag. She slips her tights down her thighs having reached inside with her hands and guides the nylon past her knees, ankles and over her toes.
Bleeding canker is only detectable once the tree displays visible symptoms of infection, ie dark bleeding lesions in the tree bark (figure 1). The lesions produce copious amounts of dark, gummy fluid in warmer weather, eventually leading to a fissure in the surface of the bark, revealing the necrotic tissue underneath (figure 2). (My tongue was blistered, swollen with cankers– white-tipped, painful ridges. I had mentioned this.) The bacteria flourish in the cambial layer and can rapidly spread to encircle the trunk killing the inner bark, cambium and outer layers of the tree. This leads to crown death as necrotic tissue prevents the distribution of nutrients and water to the upper parts of the tree. Splits and cracking in the bark also leave the infected tree vulnerable to secondary fungal infections— (Maybe I could not cry out; maybe this was the reason why my please came out like a whine—) if the initial infection does not kill the tree, then the fungus taking advantage of the tree’s compromised health often will. 8
2. Staining typical of bleeding canker
To wipe away a slow tearing; opened up, split to create an involuntary wetness and hurting like the mouth clenching my tongue between teeth biting down. To wipe the sound of flesh on flesh, hitting grew louder, was louder. Maybe I could not wipe away torn hair—maybe this is the reason I had been crying snot. To (fragments picked off fists winding, still slick with pinkish hard won fluid) wipe away on jeans, tissues and the skirt of my dress. He was waiting for a final pop in the green expanse of freshly mown grass like hair cut short to prevent a good grip: a tactic, his slick greasy skin giving no traction.
Local councils responded with unnecessary widespread felling. (He was smooth and recently shaven. I was not. I was embarrassed because I was hairy, easily grasped and parted.) However, many trees
were able to recover from infection, rendering such measures premature. As a result the UK Forestry Commission chose to recommend only removing trees that presented an immediate danger to the public.6 Similar forms of bleeding canker 6. “Specific Recommendations for the Management of Bleeding Canker of Horse Chestnut”, UK Forestry Commission, http:// www.forestry.gov.uk/website/forestresearch.nsf/ByUnique/ INFD-6L4ER3, retrieved 2010-07-09. 10
to the Phytophthora genus are soil-borne, waterborne (“The last girl, she was really wet”, he said.) and even airborne. Researchers are unable to determine how the Pseudomonas syringae bacterium is spread, although it is commonly accepted that it passes through the groundwater. In 2007 Boxmeer city council in the Netherlands hired Allicin Tree Care to begin a trial treatment of 20 infected trees on the Museumlaan. This trial established the efficacy of Allicin’s patented treatment. The company went on to form a partnership with JCA Limited to develop Conquer™.7 JCA Limited released this product for nationwide treatment of bacterial infections in 2009. Conquer™ is comprised of Diallythiosulfide, the anti-bacterial/ anti-fungal agent present in garlic. As of 2010, this 7. “Conquer™ is a natural substance and one of nature’s most effective anti bacterial and anti fungal agents. Whilst known to man for centuries it has been unavailable in quantity or at sufficient strength. Our partners have a worldwide patent for producing Conquer™ for use in horticulture and arboriculture. Conquer™ is manufactured from Garlic and grown under European GAP (Good Agricultural Practice) conditions. Produced without chemicals, it is biodegradable and environmentally safe. It has been tested by TNO, Organisation for Applied Scientific Research which proved that it destroys Pseudomonas syringae pv aesculi”—“A New Cure for Horse Chestnut Bleeding Canker”, Allicin Tree Care http://www.prnewswire.co.uk/cgi/news/ release?id=248829, retrieved 2010-10-01. 12
s pecific treatment has proven successful in ridding the A Hippocastanum of Pseudomonas syringae. However, the treatment requires specialist equipment that many councils do not have access to. With an average 46% infection rate, charting the course of an infection and felling remain the only options available to many local councils. (Later on, when he was done, he told me my crying was a healthy release of emotions.) For the trees that survive, their limbs and
structure are often badly warped, the bark compromised and insufficient in preventing secondary infections. I nodded, but it hurt because my scalp was bruised.
-I don’t understand. What did he do? -He had already started to shove his fingers up inside me, so I told him that I didn’t want to have sex. He told me we weren’t. -And then it started to hurt. He kept trying to fit more and more in. -I begged him to stop. -No, he didn’t. 13