This NebGuide discusses how to identify Aphanomyces root rot of sugar beet. Crown Rot Disease Management Acknowledgements Diseases are one of the primary yield-limiting factors affecting successful sugar beet production in the Nebraska Panhandle and other areas in the Central High Plains. Foliar diseases such as Cercospora leaf spot, curly top, and powdery mildew do occur, but are normally easier to control than soilborne diseases. Diseases caused by soilborne, root-rotting pathogens often cause more devastating losses because they are difficult to detect before serious damage occurs, and control measures are often ineffective or impractical. This publication provides information on the disease, how to distinguish it from other common root diseases of sugar beet, and how to best manage it.
Infected plant is on the left.
Note the thin hypocotyl and lack of wilting in young leaves. Foliage of plant infected with Aphanomyces cochlioides . Note the dull green of newer leaves and wilting and yellowing of older leaves. Young root infection showing yellowish-brown internal discoloration. Roots infected at the distal end, resulting in a tip rot.