Robert Kornacki, age 9, of West Warwick, R.I., for his question:
WHAT HAS HAPPENED TO THE AMERICAN CHESTNUT TREE?
Early settlers in America found chestnut trees growing abundantly. They proved to be most valuable since they provided long lasting wood, a substance called tannin used in tanning leather and also large crops of nuts. As the country continued to grow, wood from chestnut trees was used for railroad ties, telephone and telegraph poles, fence posts and furniture.
The American chestnut tree is a most spectacular tree. It grows to be about 100 feet high and its branches spread very wide. It is a native to North America, Asia, Africa and Europe.
American chestnuts once grew from central Maine, along the Appalachian Mountains and westward to Arkansas. Today the chestnut blight has almost entirely destroyed them.
The disease was first discovered in the New York City Zoological Park in 1904. Later it was determined that a fungus from northeast Asia was the cause of the disease and had probably entered North America on Asiatic chestnut nursery trees.
The infection spread from New York City to New England. The disease proceeded to wipe out entire chestnut stands in New England forests and along the eastern slope of the Allegheny and Blue Ridge mountains. In less than 50 years after the blight was discovered, it had reached every part of the natural range of the American chestnut.
Birds, insects and winds carried the spores of the deadly fungus from infected areas to healthy ones, while continued shipments of infected nursery stock, seed and logs also widened the infected area. It is estimated that more than 9 million acres of chestnut forest stands were killed.
Today old living chestnut trees are very rare. About 20 million pounds of European chestnuts are imported to North America each year, chiefly from Italy. But the blight has hit Europe, too, and fewer chestnuts will be available in the future.
Chestnut sprouts in many woods have now grown large enough to bear burs, the pods where the fruit is developed. But native chestnut sprouts or seedlings are only temporarily resistant to the chestnut blight.
The blight is caused by the fungus Endothia parasitica. It attacks the bark of the tree and spreads during damp weather. The blight went unchecked by man because he was unable to prevent the dissemination of fungus spores by the wind, birds and insects.
Although many methods have been tried during recent years to find an effective control for the chestnut blight, none has proved effective. Numerous claims have been made for some chemicals in the fight, but none has proven to be really effective.
Perhaps the answer will come with the introduction of healthy Asiatic chestnut trees that are known to be resistant to the blight.