Bacterial blight is caused by Xanthomonas campestris pv malvacearum (Smith) Dye. We will use the abbreviation X. mal. in referring to the pathogen. The pathogen was known as Bacterium malvacearum E.F. Sm. fifty years ago when the Cotton Disease Council was organized. Fifty years and several name changes for the pathogen have note altered the fact that bacterial blight is a major disease of cotton. In 1936 the popular name was angular leaf spot and the pathogen was recognized as much for causing seedling damage as it was for causing leaf shed and boll rot. You may question, fifty years of research and bacterial blight is still a major disease? The qualified answer is yes, but only in some regions and on some farms in the USA cotton belt. The fifty years of research has not been in vain because understandings were gained and materials developed which are being used by some farmers and in some regions with 100% control of bacterial blight. The problem is that the understandings and materials, for various reasons, are not being uniformly applied across the cotton belt. The bacterial blight pathogen could be eradicated from the U.S. cotton belt simply by effectively applying what we know and have on hand, but we are getting ahead of the story that is to be relayed to you.