Striga hermonthica which is commonly known as purple or giant witch weed is a semi parasitic weed that belongs to the family orobanchaceae. It is devastating to many crops mainly to sorghum, maize and rice. Striga hermonthica may have developed in north east Africa especially around the boarder of Ethiopia and Sudan.But, appears to have most suitable ecology in western and central Africa long ago. While its spread from previously infested to non infested parts of Ethiopia has increased mainly in the past 100 years: there are parts of the country with suitable climate to which it has not yet...