NEW MARKET, Va. (AP) Caught the common cold? Then take a common aspirin.
Mothers have been dispensing this all-purpose cure-all to their families through the ages as a way of providing relief from headaches and sniffles, muscle aches and joint pain.
Small wonder then, why an important aspirin ingredient salicylic acid shouldn't be used as an Earth-friendly aid for warding off plant diseases.
Scientists with the U.S. Department of Agriculture, among others, are studying how salicylic acid prods plants into releasing their natural defenses against harmful fungi, bacteria and viruses. They envision it as a commercially viable alternative to synthetic pesticides a natural way to extend the life of susceptible yet popular crops.
EDITOR'S NOTE Dean Fosdick retired in May 2001 after 23 years with The Associated Press, 15 of those as Alaska bureau chief. He has covered the Exxon Valdez oil spill, volcanoes, galloping glaciers and harvesting Alaska-grown 100-pound-plus cabbages. He can be reached at: deanfosdick(at)netscape.net
Researchers first ran into the phenomenon called ''system acquired resistance'' (SAR) back in the 1930s, the USDA says. Plants make salicylic acid naturally and use it for defending against a variety of ailments. That includes attacks by certain plant pests, like aphids.
But only recently have companies begun producing it and similar compounds as a way of activating SAR in crops.
''The basic research is becoming more and more applied,'' says Roy Navarre, a plant geneticist and team leader with the USDA's Agricultural Research Service. ''Over 15 companies are marketing products generically as plant activators.''
''None acts directly on pathogens (something able to cause diseases), like a pesticide would,'' he says. ''They just signal the plant to mobilize. It has been used with great success on lettuce and leafy crops, (and) tomato wilt virus.''
Navarre, from his Vegetables and Forage Crops Research Unit at Prosser, Wash., is concentrating his research effort on potatoes. His particular interest lies in determining which diseases and insects can be controlled by salicylic acid sprays, how long it takes the sprays to kick in and how long they remain effective.
''There are quite a lot of pathogens in potatoes,'' Navarre says. ''If we could just juice up potato responses, that would be important.''
Diseases and insects can greatly eat into the yield and quality of potatoes, a crop generating $3 billion a year in U.S. farm sales and a dinnertime staple for some 1.5 billion people worldwide.
While his team is working on SAR responses via potato roots, other USDA researchers are measuring other potato components, like leaves, stems, roots and tubers.
It's possible one activator is more effective on leaves while another works better on roots, Navarre says.
Still another research goal is to determine which plant defense genes are involved in boosting the effects of salicylic acid. The genes could be used for making new potato varieties better able to resist diseases, the USDA says.
''The better we're able to understand SAR, the better we're able to use it,'' Navarre says.
Meantime, Navarre has discovered some interesting relationships between plants and plant diseases.
''It's a lot like little wars sometimes: You see measures and counter-measures. It starts with surveillance. When it (the plant) detects those action signals, it tries to mobilize a defense.
''Pathogens, on the other hand, may try to stop the plant from doing this, or they may try working around it.''
He says plants often become diseased because they don't see the pathogen in time. Growers ''should use the inducers before their crops are attacked, by spraying every three- to four weeks,'' he says.
Navarre and his fellow scientists are hoping healthier plants and fewer pesticides will be among the benefits associated with knowing when to activate system acquired resistance.
So consider reaching for some plant aspirin for treating what ails a few of your favorite plants. Commercial varieties will be coming soon to a store shelf near you.
On the Net:
For more about using aspirin to treat plant aches and pains, see the USDA's Agricultural Research Service: http://www.ars.usda.gov/is/AR/archive/dec03/plant1203.htm
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