in the United States has been controlled through the use of several management strategies, including quarantines imposed on affected areas, control of movement of farm equipment between infected and uninfected areas, herbicide application, and imposed "suicidal germination". For the latter, in fields not yet planted in crops, seeds present in the soil are induced to germinate by injecting Ethylene gas, which mimics the natural physiological response tied to host recognition. Because no host roots are available, the seedlings die. Unfortunately, each mature Striga plant can produce tens of thousands of tiny seeds, which may remain dormant in the soil for many years. Thus, such treatments do not remove all seeds from the soil. Moreover, this method is expensive and not generally available to farmers in developing nations of Africa and Asia. Another method called trap cropping involves planting a species in an infested field that will induce the Striga seeds to germinate but will not support attachment of the parasite. This method has been used in sorghum plantations by planting Celosia argentea between the sorghum rows. Cotton, sunflower and linseed are also effective trap crops. Planting silverleaf desmodium (Desmodium uncinatum), as is done in push-pull intercropping, inhibits Striga seed germination and has worked effectively intercropped with maize. Increasing nitrogen levels in the soil, growing Striga-tolerant varieties, trap-cropping, and planting susceptible crops harvested before witchweed seed is produced, are proven tactics. Coating maize seeds with fungi or a herbicide also appears to be a promising approach. An example is TAN222, the "Striga-resistant" maize variety which is coated with the systemic herbicide imazapyr, to which it is resistant. Any witchweed seeds sprouting when this maize is in the seedling stage are poisoned when their haustoria embed in the seedling's roots. Several sorghum varieties have high levels of resistance in local conditions, including 'N-13', 'Framida', and 'Serena'. 'Buruma', 'Shibe', 'Okoa' and 'Serere 17' millet cultivars are considered to be resistant in Tanzania. Some maize varieties show partial resistance to witchweed, including 'Katumani' in Kenya. In a number of rice cultivars, including some cultivars of NERICA (New Rice for Africa), effective pre- and post- attachment resistance mechanisms have been identified. 'StrigAway'™ herbicide-resistant, herbicide impregnated maize has been shown to reduce the seed bank by 30% in two seasons. Importance Maize, sorghum, and sugarcane crops affected by witchweed in the United States have an estimated value well over $20 billion. Furthermore, witchweed is capable of