THE traditional playground game of conkers has come under threat from a disease spreading to horse chestnut trees in Lancashire.

Thousands of schoolchildren could be disappointed in years to come with the disease attacking the tree which produces conkers.

Called ‘phytophthora bleeding canker,’ the disease on the bark causes infections which bleed a dark reddish brown sticky fluid similar to tar.

The current hotspots for the condition, which can kill a fully grown tree within three years, include Laund Clough and Sycamore Woods in Baxenden and Heald Wood, near Burnley.

Experts fear the disease, which has already hit woodlands in the south of England, could have a similar impact to the Dutch elm epidemic in the 1960s and 70s, which saw most of the elm tree population in the country wiped out by a fungal disease spread by the elm bark beetle.

Colin Riley, who manages woods in East Lancashire on behalf of the Woodland Trust said: “This is a serious threat in the long term.

"It was a strain of phytophthora that caused the potato famine in Ireland.

“It has usually been spotted in the south but over the last 10 years it has spread to the north and although we can’t say this for definite it appears to be because our climate up here is getting warmer.

“There is not much that can be done because it is a disease which cannot be controlled very easily.

“And although I haven’t noticed a drop in conkers this year, this disease will inevitably have an effect in the future.”

Several species of the fungus-like micro-organism have long been known to cause bark infections in horse chestnut, though cases were relatively uncommon until recently.

The bleeding fluid is produced by the tree in response to the infection, which kills the inner bark and outer layers of wood, causing disruption to water and nutrient transport.

It spreads through pores in the bark and can remain for long periods in the soil.

HORSE CHESTNUTS Conkers are the fruit of the horse chestnut tree.

The tree originates from Albania and Greece and was introduced to the UK in the 1600s. It takes the name ‘horse’ in reference to its perceived strength. Historically 'horse' also meant ‘powerful’.

The first recorded game of conkers using horse chestnuts was held in 1848.

Horse chestnuts are not suitable for human consumption as they contain a toxin which destroys red blood cells. They should not be confused with chestnuts which are edible.

The World Conker Championships take place at Ashton, near Peterborough, every October.