For the past 50 years , areas near the border between North and South Carolina have been ground zero for a fierce battle in the warfare against a devastating weed . Union and nation official and local farmers have been fighting the only eff U.S. infestation of witchweed ( Striga asiatica ) , an incursive plant that has crippled key segments of the agricultural industry in countries around the ball .
The leechlike locoweed is a danger to some of our nation ’s most crucial crops , including corn , sorghum molasses , sugar cane , Sir Tim Rice and other industrial plant belong to the supergrass family . It taps straightaway into a works ’s root system to rob it of nutrients and moisture — dramatically reduce yield .
Unfortunately , witchweed also is very fertile . A single plant life can produce as many as 50,000 dust - alike seeds that can last in the territory for a decade or more , making eradication a ruffianly and time - consuming unconscious process .
But for farmers battling the weed in North and South Carolina , the end seems tantalizingly close .
“ We ’re 99 percent of the agency there , ” say Alan Tasker , internal noxious weed program manager with the USDA ’s Animal and Plant Health Inspection Service . “ Not only have we halted the spread of witchweed over the past five decades , but we ’ve dramatically reduced the number of infested acres , as well — down from 450,000 in the 1950s to about 2,000 today . Our end is to eradicate it once and for all . ”
Witchweed is aboriginal to Africa , India , the Middle East and China . No one is trusted how it made its mode to the Carolinas . A alumnus bookman from India first spotted the lissome , red - blossomed pest in 1955 . He know it well because of its withering shock on his own country ’s sorghum crops .
To avert a similar disaster for U.S. grower , Congress created an eradication programme in 1957 led by a USDA program that by and by became APHIS . The agency found a research place and farm where it educate the scientific discipline - based control condition methods that have make salient solution . The successful program is built around three decisive phases , each take stuffy quislingism among Union and nation official and farmers in the Carolinas :
1 . place and represent all witchweed plague . Because witchweed is so fecund , discover each and every specimen of the human foot - tall plant is lively . In addition to farmers checking their own nation , scouts are sent out to situate infested site , traveling on foot and on horseback ahead of time in the plan and later inall - terrain vehicles . There are penalties for failing to report the green goddess and bounty paid for sightings by eligible party .
“ We typically have neat cooperation from local husbandman , who know the risk witchweed poses to their crop , ” Tasker say .
2 . Quarantine sphere with witchweed . Although bantam witchweed ejaculate can be spread by wind or by water , human activity is often the culprit . For that reason , the area where witchweed is discover are cursorily quarantined . Machinery used at the site and any crops harvested with soil attached must be make clean thoroughly to remove witchweed seeds . Growing the grass crop favored by witchweed is strictly prohibited until the pest is totally eradicate in the quarantine segment of a field . Instead , Fannie Farmer must leave the land fallow or convert to craw that are harvested well above the grease line .
3 . Control witchweed . official remove witchweed plant when they ’re find and practice both foliar - give and soil - applied herbicides for deterrence . destroy the 10 of thousands of microscopic seed that may already be in the territory , though , is tougher and more time - consuming . Some sow sprout powerful off and are kill by the herbicide . But others can lurk for years .
“ Allowing grassy weeds to grow in the area or planting a crop that is susceptible to witchweed can actually trigger dormant sends to germinate , even if they are deep hugger-mugger , ” Tasker says . “ We have deterrent example of parasitical weed seeds remaining abeyant in a fallow plain for 50 years and then sprouting as soon as the preferred legion crop is planted . ”
One good technique for command hibernating seminal fluid is “ suicide sprouting . ” Ethylene gas pedal — a instinctive ripen federal agent produced by yield , veg and flowers — is injected into the soil and causes the seeds to shoot . Without a host works to impound to , the new seedlings wither and die . Another advance is to fume the soil with chemicals to destroy any seeds that remain .
“ disregarding of the technique used , we slur - ascertain the fields for year afterwards to ensure the weed is sincerely eradicated , ” Tasker say .
Tasker and Jim Westwood of Virginia Tech have organized a special day - long symposium on the witchweed program and other parasitic grass will take place during the51st one-year meetingof the Weed Science Society of America . The event is scheduled for Feb. 7 to 10 , 2011 , in Portland , Ore.
