|Species:||Fusarium sambucinum and Fusarium solani var. coeruleum|
Fusarium dry rot is characterized by an internal light to dark brown or black rot and dryness of the potato tuber. The rot may develop at an injury such as a bruise or cut. The pathogen penetrates the tuber, often rotting out the center. Extensive rotting causes the tissue to shrink and collapse, usually leaving a dark sunken area on the outside of the tuber and internal cavities. Yellow, white, or pink mold may be present.
Several other diseases and physiological disorders, including Pythium leak, pink rot, late blight, and suboxygenation (blackheart), also cause brown to black internal discoloration of tubers. Leak and pink rot are wet rots; tubers exude a clear fluid when squeezed. Late blight is a less aggressive rot that generally does not penetrate into the center of the tuber and causes reddish-brown lesions. Poor air circulation or extremes in temperature that result in low internal oxygen concentrations can cause a smoky gray to black discoloration of tissue, but the tissue is never brown and is very firm.
Avoiding bruising tubers is generally the best way to avoid dry rot. Avoid planting dehydrated tubers. Remove infected tubers from storage as soon as infection is detected.
- El-Banna, A.A. Scott, P.M. Lau, P. Sakuma, T. Platt, H.W. and Campbell, V. (1984). Formation of Trichothecenes by Fusarium solani var. coeruleum and Fusarium sambucinum in Potatoes. American Society for Microbiology. p1169-1171. 0099-2240/84/051169-03
- Rosemary Loria. (1993). Fusarium Dry Rot of Potato. Cooperative Extension, New York State, Cornell University. Fact Sheet p726. Retrieved: 2010-07-28.