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Appendix 5.

Witchweed on corn


Striga asiatica (L.) O. Kuntze, a native of Asia and Africa, and a root parasite of grass crops such as corn and sorghum, was first discovered in the Western Hemisphere in southeastern North Carolina in 1956. Since then, most of the 432,000+ acre infestation in the eastern Carolinas has been eradicated. 

While most of the people who made the witchweed program such a success are now retired or passed away, their heroic efforts to protect the U.S. grain industry from this parasitic menace will never be forgotten.  Their work and ideas were a major inspiration for the development of a National Early Warning and Rapid Response System for Invasive Plants, which is the subject of these proceedings.

If we are successful in our efforts to develop a national program to detect, assess, and rapidly respond to new invasive plants, we will never again see the likes of leafy spurge (Euphorbia esula), purple loosestrife (Lythrum salicaria) enter our fair land and grow silently unnoticed for decades until they become an unstoppable cancer changing and consuming the landscape of America.

comparative damage on corn by witchweed.

1.  Witchweed damage on corn.  Witchweed infested vs noninfested corn.

2. Comparison of witchweed seeds (smallest) to tobacco seeds (next largest), mustard seeds (largest), and human hair.

Witchweed distribution map as of 2000, found in North and South Carolina

3. Current distribution Map of witchweed in the U.S. As of 2000, it occurs only in North and South Carolina.

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