Understanding ‘foamy bark rot’ of Fukumoto navel

‘Fukumoto’ navel orange budwood was introduced into California from Japan by Glenn Dale of the United States Department of Agriculture (USDA) in 1983 (www.citrusvariety.ucr.edu). Fukumoto has many desirable attributes. It matures early (late October), typically three to four weeks earlier than Washington navel, it has deep reddish rind color that makes it highly desirable for packinghouse processing. However, “foamy bark rot” disorder of Fukumoto causes serious and understandable concerns that may exceed the positive attributes of the variety. Many Fukumoto groves in California are experiencing a decline of trees leading to their death in some Research Project Progress Report CRB Funded Research Reports 2010