The chestnut blight come to U.S. shore via Europe through the East Coast on Chinese chestnut trees and quickly attacked the genetically unprepared American chestnut .
Chestnut blight is a fungus that circulate via spore in the air , in raindrops or on animals ; it attacks open lesion on the tree diagram and enters through an injury in the tree ’s bark .
The fungus spread out throughout the tree , toss off tissue as it pass on . finally , the tree diagram ’s metabolic organisation becomes decease off , unable to get food . The tree finally die .
“ There are between 100 million and 100 billion American chestnut tree sprout rise in the aboriginal range [ today ] , and most of these are plague free , ” says Frederick V. Hebard , Ph.D. , faculty pathologist at The American Chestnut Foundation ’s Meadowview research farms in Meadowview , Va.
“ They temporarily escape blight because their blight - infected neighbors are too small to bear cankers that can give rise to more than one girl canker per mother canker ( the little cankers simply do n’t produce enough spores ) . Thus , blight relative incidence remains at a scummy level , and the chestnut sprouts can hold up to be more than 40 to 60 yr old .
“ The sprouts stay small because they are in the shade of other mintage of trees , ” Hebard continues . “ However , when that overstory is removed by abridge , windthrow or other to-do , the chestnut sprouts start to grow very apace .
“ The sprout increase their charge per unit of diameter growth from less than 0.5 millimetre per year to 5.0 millimetre per year , or more . The increased sunlight also induces them to flower , and it is those trees that we pollinate .
“ However , as the sprouts increase in size , the cankers also increase in size . By 10 years after cutting , the canker are 10 time larger on the orotund sprout , producing 10 time as many spore . This means they are giving wage increase to 10 times as many girl canker .
“ After one year , each of these daughter canker gives move up to 10 granddaughter canker and there are now 100 prison term as many cankers ; after two year , 1,000 , and after three age , 10,000 time as many canker sore . Soon , almost all the sprouts that had been get away blight for years are killed by it . Most of the sprout are as susceptible to blight as the original chestnut tree trees . ”
Efforts to Save the Tree
The U.S. governance first became mindful of the curse of the Taiwanese chestnut blight in 1904 , and see the fungus ’ potential difference to pass over out the American chestnut tree Sir Herbert Beerbohm Tree .
In an effort to cross the pestis ’s destruction , the U.S. Department of Agriculture and the Connecticut Agricultural Experiment Station launched programs to breed a blight - resistant American chestnut tree Sir Herbert Beerbohm Tree .
The American Chestnut Foundation469 Main StreetP.O. Box 4044Bennington , VT 05201 - 4044(802 ) 447-0110www.acf.org
Canadian Chestnut Councilc / group O Mr. Charles HookerR.R. # 2Orangeville , ON , L9W 2Y9(519 ) 942-8085www.uoguelph.ca/~chestnut
Because of limited knowledge of genetic science at the time , these attempts at create a resistant tree did not prove successful . tree that were able to fight off the blight , including the Chinese chestnut , did not possess the desired characteristics of the American chestnut tree , which include marvellous , consecutive growth and a gamy - quality wood .
give up in 1960 , the administration programme did however succeed in supply a foundation for The American Chestnut Foundation ’s attack upon the blight .
so as to guard off the blight , American chestnut must possess a transmitted tendency toward ohmic resistance , a sensitivity found in the Taiwanese chestnut , which only shows cosmetic harm when attack by the fungus .
By combining the genes of these two Sir Herbert Beerbohm Tree , TACF is essay to create a tree that will have all the attributes of the American chestnut tree , but will not be affected by blight .
The way to achieving this finish is backcross breeding , which call for crossing insubordinate Formosan chestnut trees to American chestnut tree tree and then crossing back to aboriginal American three more times .
After the third backcross , the result is a tree that is only 1/16 Chinese and the eternal rest American . Through intercrossing and further testing , scientists are able to determine which of these tree diagram are highly resistant to the blight . The progeny of those trees that pass the test will be planted back in the wood .
How Hobby Farmers Can Help
The American Chestnut Foundation has high hope for its backcross American chestnut trees , and has future plans for re-afforestation in the Sir Herbert Beerbohm Tree ’s native range . This is where hobby James Leonard Farmer come in in .
They are also encouraged to visit , tour and help out on the constitution ’s research farm in Meadowview , Va. , and have access to expert advice on growing chestnut . Members are also permitted to buy sodding American chestnut seeds and seedlings through the organization .
Once the American chestnut tree is quick for re-afforestation , small Farmer will be needed for a more hands - on advance , allot to Dale Kolenberg , communication director for The American Chestnut Foundation .
“ Farmers and other private land possessor can get in cutaneous senses with us to allow us know they are concerned in our reforestation efforts , and when we have our last product , help oneself plant the blight - resistant trees , ” she says .
With the help of those dedicated to bringing the American chestnut tree to its former glory , The American Chestnut Foundation hopes to see this regal tree diagram once again dominating Eastern forests . A combination of advancements in genetic research and a passion for this extra tree diagram may actually make this possible .
This clause first appeared in the March / April 2004 issue ofHobby Farmsmagazine . Pick up a written matter at your local newsstand or tack and feed store .
