ON one of the reserves the other day I spotted some conkers that had fallen from one of our mighty horse chestnut trees.

My mind immediately shot back to fond memories of hours and hours spent conker picking as a child. Then the further hours doing battle in the playground and arguing over the rules to the great game and accusing people of tampering with their conkers. So I thought I would write about the beloved horse chestnut tree.

However, when it came to doing some research for this article I discovered some rather sad news. The future of Britain’s horse chestnut trees could be under threat because of a disease which has swept across the country. A newly discovered bacteria is causing a condition called “bleeding cankers”.

Cankers are an area of dying bark, like sores that ooze liquid, most have existed on the trees for several decades and were caused by a fungus, which was less virulent. However, there is now a new infectious bacterium (Pseudomonas syringae pathovar aesculi) that is the cause of these cankers and it is creating much concern amongst scientists, as it spreads rather quickly.

The infection weakens the trunk or branch, and often the tree needs to be felled for safety reasons. Often infected bark becomes cracked which can lead to further problems such as rotton wood fungus, which exacerbates the problem. It is believed the infection possibly stems from Indian chestnut trees imported from the Himalayas for planting, but is now present in many European countries.

Unfortunately this is not the only problem that the horse chestnut has to face. The leaves of this fine tree are also under attack from both a moth and a fungus. The horse chestnut leaf-mining moth (Cameraria ohridella) was introduced in Britain in 2002 and is now widespread. The tiny adult moths lay eggs on the foliage. After hatching, the caterpillars enter the leaves and eat the internal tissues. By August the foliage may be extensively damaged, leading to early leaf fall. This pest overwinters as pupae in the leaf mines.

Leaf blotch (Guignardia aesculi) is caused by the fungus Guignardia aesculi, which was accidentally introduced from North America early last century.

Irregular brown blotches develop on leaves from midsummer onwards, often most frequent at tips and margins. The initial appearance is distinct from the leaf miner, but the end result is similar and damage by both may be mistaken for early autumn colour.

The stresses put on the trees by such diseases, means they have less vigour to put into fruit production, hence less conkers.

I personally think it would be a crying shame if we were to lose these magnificent trees. For one we would lose the traditional playground game. The first recorded game of conkers was on the Isle of Wight in 1848 and was modelled on a 15th century game played with hazelnuts, also known as cobnuts. These problems facing the tree have already caused problems for the World Conker Championships, held in Ashton, Northamptonshire.

By DAVID FARTHING