Tuber soft rot

Carputo, D., Cardi, T., Palta, J. P, Sirianni, P, Vega, S., Fruseiante, L. (2000b). Toleranee to low temperatures and tuber soft rot in hybrids between Solanum commersonii and Solanum tuberosum obtained through manipulation of ploidy and endosperm balanee number (EBN). Plant Breeding, 119, 127-130. 

Carputo, D., Speggiorin, M., Garreffa, P, Raio, A., Monti, L. M. (1996). Sereening for resistanee to tuber soft rot and blaekleg in diploid Solanum speeies and S. tuberosum haploids. Journal of Genetics and Breeding, 50, 221-226. 

Carputo, D. C. T., Speggiorin, M., Zoina, A., Frusciante, L. (1997). Resistance to blackleg and tuber soft rot in sexual and somatic interspecific hybrids with different genetic background. American Potato Journal 74, 161-172. 

McGrath, J. M. W., Christie E.,Haberlach, Geraldine T., Wielgus, SusanM.,Uchytil, ThomasF.,Helgeson, John R (2002). Introgression and stabilization of Env/ma tuber soft rot resistance into potato after somatic hybridization of Solanum tuberosum and S. brevidens. American Journal of Potato Research 79,19-24. 

McGuire, R. G., Kelman, A. (1984). Reduced severity of Erwinia soft rot in potato tubers with increased calcium content. Phytopathol., 74,1250-1256. 

Figure 1 2.3 Soft rot of potatoes developed in storage due to storage of wet tubers, condensations and anaerobic conditions in the storage.

Watery soft rot caused by S. sclerotiorum and S. minor often develops on tubers that appear sound at harvest but subsequently succumb in storage (Gaudineau and Lafon, 1958). The tubers become covered with a dense white mycelium and irregular sclerotia, which progress from white to dark brown or black. Though storage at low temperatures repressed development, S. sclerotiorum can cause serious losses at low temperature (Johnson, 1931). 

Soft rot develops when bacteria infect fleshy fruit, tubers, or roots, secreting enzymes and perhaps toxins that break down the cells. These infections begin as small, water-soaked spots that turn mushy and smelly. 

Prevention and Control To avoid soft rots, handle fruits and vegetables (especially those you plan to store) carefully, both during and after harvest. Soft rot bacteria enter wounds produced by rough handling as well as those caused when fruits, tubers, and roots are frozen or damaged by insects. Soft rots usually need a high moisture level to develop, so store produce in a cool, dry place. If you have had trouble with soft rot in past years, rotate crops to reduce the spread of the disease in the garden. 

Potatoes with a black, rotted ring at stem ends. Cause Bacterial ring rot. Tubers have a soft, light brown ring in the flesh near the skin. See Leaves discolored and puckered or curled on page 188 for controls. 

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