NEWPORT BEACH, Calif.--(BUSINESS WIRE)--American Vanguard Corp. (NYSE:AVD) announced two changes in its business development and marketing functions. First, effective July 31, 2015, Glen D. Johnson, Senior Vice President and Director of Business Development for the company’s principal operating subsidiary (AMVAC) will be leaving the company to take on the role of CEO and President at another company. Mr. Johnson has served AMVAC in his current role for the past 17 years with a focus on acquisit