Is My Horse Chestnut Sick – Diagnosing Diseases Of Horse Chestnut Trees

Is My Horse Chestnut Sick – Diagnosing Diseases Of Horse Chestnut Trees

By: Tonya Barnett, (Author of FRESHCUTKY)

Horsechestnut treesare a large type of ornamental shade tree native to the Balkan peninsula. Muchloved for its use in landscaping and along roadsides, horse chestnut trees arenow widely distributed throughout Europe and North America. In addition toproviding much welcome shade during the hottest parts of summer, the treesproduce large and showy flower blooms. Though relatively simple to grow, thereare several common issues which lead to the decline of plant health – issues thatmay cause growers to ask, ‘is my horse chestnut sick?’

What’s Wrong with My Horse Chestnut?

Like many types of trees, diseases of horse chestnut treesmay arise due to insect pressure, stress, or less than ideal growingconditions. The severity of horse chestnut diseases may vary greatly dependingupon the cause. By familiarizing themselves with signs and symptoms of declinein tree health, growers are better able to treat and prevent disease of horsechestnut trees.

Horse Chestnut Leaf Blight

One of the most common diseases of horse chestnut trees isleaf blight. Leaf blight is a fungal disease which causes large, brownish spotsto develop on the tree’s leaves. Often, these brown spots will also besurrounded by yellow discoloration. Wet weather in the spring allows foradequate moisture needed for the fungal spores to spread.

Leaf blight most often results in premature loss of leavesfrom trees in the fall. While there is no treatment for leaf blight in the homegarden, growers can help to combat the issue by removing infected leaf litterfrom the garden. Destroying the infected plant matter will help to bettercontrol future leaf blight infections.

Horse Chestnut Leaf Miner

Horse chestnut leaf miner is a type of moth whose larvaefeed on horse chestnut trees. The tiny caterpillars create tunnels within theleaves, and eventually cause damage to the plant’s foliage. Though it has notshown to cause serious damage to horse chestnut trees, it may be of someconcern, as infected leaves may fall prematurely from trees.

Horse Chestnut Bleeding Canker

Caused by bacteria, bleeding canker of horse chestnuts is a disease that impacts the health and vigor of horse chestnut tree bark. Canker causes the bark of the tree to “bleed” a dark colored secretion. In severe cases, horse chestnut trees may succumb to this disease.

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A sad milestone in the spread of a disease mortally affecting Britain's horse chestnut trees was passed this week when one of the country's noblest horse chestnut avenues was finally cut down.

The trees lining the drive of 16th-century Barrington Court at Ilminster in Somerset, had become stricken with bleeding canker, an infection caused by a virulent bacterium that produces a rust-coloured liquid which oozes from the bark and eventually kills the tree.

Barrington Court is owned by the National Trust – it was one of the first properties the Trust bought, in 1907 – and Trust staff had been trying to save the avenue of 68 majestic trees which have lined the approach to the Tudor manor, built in 1514, for nearly a century. But they have had to admit defeat and this week the final 23 horse chestnuts were cut down by tree surgeons, They will be replaced with disease-resistant chestnut-leaved oaks.

It is just the latest effect of a disease which has been taking an increasing toll on Britain's conker trees in the last five years, and looks as if it may threaten the conker's very existence.

The bleeding was first thought to be caused by Phytophthora ramorum, the agent which causes another serious tree infection known as sudden oak death, but investigations have shown it is caused by a separate pathogen, a bacterium named Pseudomonas syringae, a variant of which targets horse chestnuts.

The disease is now widespread in Britain and a survey undertaken by the research arm of the Forestry Commission in 2007 found that just under half of all horse chestnuts assessed were showing symptoms of the infection to some degree, although the extent of the disease varies in different parts of the country. Thousands of horse chestnuts – of which there may be half a million in Britain – are thought to have been already cut down because of it.

The situation has been made worse by the fact that conker trees are being devastated by a quite separate infestation, caused by an insect – the horse chestnut leaf-miner moth, whose larvae burrow into the leaves in their millions and cause them to turn brown in high summer rather than in autumn. The moth is thought to have reached Britain, perhaps on a long-distance lorry, in about 2000 or 2001 from the Balkans where it was first recorded as a new species in Macedonia in northern Greece in the late 1970s.

Horse chestnut leaf drop

Horse Chestnut leaf drop is probably due to Leaf Blotch disease

Q. Our city street in Pennsylvania is lined on both sides with Horse Chestnut trees. These trees were beautiful in the spring, but through the summer months many of the leaves turned yellow and brown, and dropped off long before they would usually drop in the fall of the year. What do you think is wrong with our Horse Chestnut trees and can we save them?

A. Horse chestnut (Aesculus hippocastanum) trees are susceptible to a fungal disease called leaf blotch. This fungal disease causes reddish-brown spots on the leaves that are often surrounded by yellow halos. Infected leaves turn brown and fall prematurely.

Leaf blotch is more severe when we have wet spring weather, but it can be equally severe during hot, dry weather.

Horse Chestnut tree

Highly valued trees can be sprayed preventatively with cozeb (Dithane, Protect Turf and Ornamental Fungicide) fungicide, but treatment is not usually warranted. Although it is unsightly and messy, leaf blotch is not life threatening.

Translate plant names – Translations of botanical names

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  • 1 Description
  • 2 Etymology
  • 3 Distribution and habitat
  • 4 Uses
    • 4.1 Medical uses
      • 4.1.1 Safety
  • 5 Other chemicals
  • 6 Anne Frank tree
  • 7 Symbol of Kyiv
  • 8 Diseases
  • 9 Gallery
  • 10 References

Aesculus hippocastanum is a large tree, growing to about 39 metres (128 ft) tall [13] : 371 with a domed crown of stout branches on old trees the outer branches are often pendulous with curled-up tips. The leaves are opposite and palmately compound, with 5–7 leaflets each leaflet is 13–30 cm (5–12 in) long, making the whole leaf up to 60 cm (24 in) across, with a 7–20 cm (3–8 in) petiole. The leaf scars left on twigs after the leaves have fallen have a distinctive horseshoe shape, complete with seven "nails". The flowers are usually white with a yellow to pink blotch at the base of the petals [13] they are produced in spring in erect panicles 10–30 cm (4–12 in) tall with about 20–50 flowers on each panicle. Its pollens are not poisonous for honey bees. [14] Usually only 1–5 fruits develop on each panicle the shell is a green, spiky capsule containing one (rarely two or three) nut-like seeds called conkers or horse-chestnuts. Each conker is 2–4 cm ( 3 ⁄4 – 1 1 ⁄2 in) in diameter, glossy nut-brown with a whitish scar at the base. [15]

The common name horse chestnut originates from the similarity of the leaves and fruits to sweet chestnuts, Castanea sativa (a tree in a different family, the Fagaceae), together with the alleged observation that the fruit or seeds could help panting or coughing horses. [16] [17]

Although it is sometimes known as buckeye, [7] for the resemblance of the seed to a deer's eye, buckeye is more commonly used for New World members of the genus Aesculus. [18]

Aesculus hippocastanum is native to a small area in the Pindus Mountains mixed forests and Balkan mixed forests of South East Europe. [19] However, it can be found in many parts of Europe as far north as Gästrikland in Sweden, as well as in many parks and cities in the northern United States and Canada.

It is widely cultivated in streets and parks throughout the temperate world, and has been particularly successful in places like Ireland, Great Britain and New Zealand, where they are commonly found in parks, streets and avenues. Cultivation for its spectacular spring flowers is successful in a wide range of temperate climatic conditions provided summers are not too hot, with trees being grown as far north as Edmonton, Alberta, Canada, [20] the Faroe Islands, [21] Reykjavík, Iceland and Harstad, Norway.

In Britain and Ireland, the seeds are used for the popular children's game conkers. During the First World War, there was a campaign to ask for everyone (including children) to collect the seeds and donate them to the government. The conkers were used as a source of starch for fermentation using the Clostridium acetobutylicum method devised by Chaim Weizmann to produce acetone for use as a solvent for the production of cordite, which was then used in military armaments. Weizmann's process could use any source of starch, but the government chose to ask for conkers to avoid causing starvation by depleting food sources. But conkers were found to be a poor source, and the factory only produced acetone for three months however, they were collected again in the Second World War for the same reason. [22]

The seeds, especially those that are young and fresh, are slightly poisonous, containing alkaloid saponins and glucosides. Although not dangerous to touch, they cause sickness when eaten consumed by horses, they can cause tremors and lack of coordination. [23]

The horse-chestnut is a favourite subject for bonsai. [24]

Though the seeds are said to repel spiders there is little evidence to support these claims. The presence of saponin may repel insects but it is not clear whether this is effective on spiders. [25]

Aesculus hippocastanum is affected by the leaf-mining moth Cameraria ohridella, whose larvae feed on horse chestnut leaves. The moth was described from North Macedonia where the species was discovered in 1984 but took 18 years to reach Britain. [26]

In Germany, they are commonly planted in beer gardens, particularly in Bavaria. Prior to the advent of mechanical refrigeration, brewers would dig cellars for lagering. To further protect the cellars from the summer heat, they would plant chestnut trees, which have spreading, dense canopies but shallow roots which would not intrude on the caverns. The practice of serving beer at these sites evolved into the modern beer garden. [27]

Medical uses Edit

The seed extract standardized to around 20 percent aescin (escin) is used for its venotonic effect, vascular protection, anti-inflammatory and free radical scavenging properties. [28] [29] Primary indication is chronic venous insufficiency. [29] [30] A Cochrane Review suggested that horse chestnut seed extract may be an efficacious and safe short-term treatment for chronic venous insufficiency, but definitive randomized controlled trials had not been conducted to confirm the efficacy. [31]

Safety Edit

Two preparations are considered: whole horse chestnut extract (whole HCE) and purified β-aescin. Historically, whole HCE has been used both for oral and IV routes (as of 2001). The rate of adverse effects is low in a large German study, 0.6%, consisting mainly of gastrointestinal symptoms. [ medical citation needed ] Dizziness, headache and itching have been reported. One serious safety issue is rare cases of acute anaphylactic reactions, presumably in a context of whole HCE.

Another is the risk of acute kidney injury, "when patients, who had undergone cardiac surgery were given high doses of horse chestnut extract i.v. for postoperative oedema. The phenomenon was dose dependent as no alteration in kidney function was recorded with 340 μg/kg, mild kidney function impairment developed with 360 μg/kg and acute kidney injury with 510 μg/kg". [32] This almost certainly took place in a context of whole HCE.

Three clinical trials were since performed to assess the effects of aescin on kidney function. A total of 83 subjects were studied 18 healthy volunteers given 10 or 20 mg iv. for 6 days, 40 in-patients with normal kidney function given 10 mg iv. two times per day (except two children given 0.2 mg/kg), 12 patients with cerebral oedema and normal kidney function given a massive iv. dose on the day of surgery (49.2 ± 19.3 mg) and 15.4 ± 9.4 mg daily for the following 10 days and 13 patients with impaired kidney function due to glomerulonephritis or pyelonephritis, who were given 20–25 mg iv. daily for 6 days. "In all studies renal function was monitored daily resorting to the usual tests of renal function: blood urea nitrogen (BUN), serum creatinine, creatinine clearance, urinalysis. In a selected number of cases paraaminohippurate and labelled EDTA clearance were also measured. No signs of development of renal impairment in the patients with normal renal function or of worsening of renal function in the patients with renal impairment were recorded." It is concluded that aescin has excellent tolerability in a clinical setting. [33]

Raw horse chestnut seed, leaf, bark and flower are toxic due to the presence of esculin and should not be ingested. Horse chestnut seed is classified by the FDA as an unsafe herb. [29] The glycoside and saponin constituents are considered toxic. [29]

Quercetin 3,4'-diglucoside, a flavonol glycoside can also be found in horse chestnut seeds. [34] Leucocyanidin, leucodelphinidin and procyanidin A2 can also be found in horse chestnut.

A fine specimen of the horse-chestnut was the Anne Frank tree in the centre of Amsterdam, which she mentioned in her diary and which survived until August 2010, when a heavy wind blew it over. [35] [36] Eleven young specimens, sprouted from seeds from this tree, were transported to the United States. After a long quarantine in Indianapolis, each tree was shipped off to a new home at a notable museum or institution in the United States, such as the 9/11 Memorial Park, Central H.S. in Little Rock, and two Holocaust Centers. One of them was planted outdoors in March 2013 in front of the Children's Museum of Indianapolis, where they were originally quarantined. [37]

The horse chestnut tree is one of the symbols of Kyiv, the capital of Ukraine. [38]

Scatter a fine layer of it around cracks and corners. The powder, made from fossils, supposedly cuts a spider up when it walks across it, which ultimately kills it. Deter spiders with conkers by placing them on window sills and in corners of the room. Walnuts are thought to have a similar effect.

Fresh chestnuts must always be cooked before use and are never eaten raw, owing to their tannic acid content. You need to remove the chestnuts from their skins by either boiling or roasting them. … Once cooked, peel off the tough shell and the papery thin skin underneath.

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