HI Guys,
I have just found and increasing number of potatoes appear to be dammaged on the inside. Some have got a ball of black in the potato, some when you cut in are completly black in the middle. Which is a little confusing. None of these potatoes showed any outwards sign of any damage.
I am going to get some photos for people to comment but i have the horabile feeling its one of the following
16. Blackheart, nonpathogenic
This injury occurs as the result of low oxygen levels in the interior of the tuber and is relatively easy to diagnose. The center of affected tubers is black to blue black, in an irregular pattern, and the border of the discolored area is usually very distinct. Darkened areas of the tuber are usually fairly firm, in contrast to those of tubers affected by Pythium leak, which are spongy. Affected tissues do not smell, and shrinking of the tissue may result in the formation of a cavity in the center of the tuber. Blackheart develops when tubers are held in a lowâ€"oxygen environment or when gas diffusion through the tubers is slowed because of extremely cold (32° F) or warm (96°â€"104° F) temperatures. This condition can also develop in the field when soils are flooded or in poorly aerated storages. Because seedâ€"piece size is effectively reduced by the death of affected tissues, plant stand and vigor are likely to be reduced.
17. Black spot, nonpathogenic
Black spot occurs in the tuber flesh just beneath the tuber periderm and appears as gray to black circular areas with diffuse borders. Because this injury is always the result of bruising, including pressure bruising, internal symptoms may be associated with flattening or other signs of mechanical injury on the tuber surface. However, black spot may occur in the absence of any obvious external damage, and mechanical injury to the tuber does not always result in internal symptoms. Many factors have been reported to affect the susceptibility of tubers to black spot. Tubers with low turgor pressure are most likely to be affected by black spot. The stem end is more susceptible than the apical end, and mature tubers are more susceptible than immature tubers. Seed quality is not appreciably reduced by black spot. Avoid deep storage piles, especially with more susceptible varieties.
20. Verticillium wilt â€" Verticillium spp., fungus
This disease produces no external tuber symptoms, but causes a light brown discoloration in the vascular tissue of tubers, which may extend halfway through the tuber. Cavities sometimes develop inside tubers. Infected seed pieces often produce wiltâ€"free plants, but soil adhering to tubers may contain the fungus and provide inoculum for infection of the subsequent crop. Pink eye, a pinkish or tan discoloration of the tuber surface around the eyes, may also develop on tubers produced from Verticilliumâ€"infected plants, but is caused by a bacterium, Pseudomonas fluorescens. Pink eye can be confused with the tuber rot phase of late blight. Because of the soilborne nature of Verticillium wilt, long rotations and the use of resistant potato varieties are recommended. Avoid late cultivation and hilling of susceptible varieties, for root pruning increases the risk of infection. The presence of the root lesion nematode, Pratylenchuspenetrans, greatly increases yield losses due to Verticillium wilt.
http://vegetablemdonline.ppath.cornell.edu/factsheets/Potato_Detection.htm
Cambourne7
We await the pictures with great interest. Can we please have close-up photo`s of both the skin of the tuber, and the cut surface of one cut through the centre crosswise.
Hubbies but most in the bin but i have managedto get a photo of one bit of the damage i need to play with it as its on my phone.
I bet the oxygen levels in a lot of people's soil have been pretty low recently, with the waterlogging they must have had.