Potato growers have been warned to be on the look-out for rotting
tubers appearing soon after stores are loaded. Localised heavy showers
have led to small pockets of soft rots in some fields, which can
cause problems in store.
"Generally the state of the crop looks good this year," notes
Adrian Cunnington, operations manager at the British Potato Council's
Sutton Bridge Experimental Unit. "But we have had some enquiries
come through from growers calling the BPC storage advice line about
rots, so there's cause for vigilance."
Soft rot, a seed-borne disease, is caused by Erwinia bacteria and
shows itself as blackleg in the crop. Wet conditions tend to exacerbate
the disease. The rotting tubers can be seen at harvest time as potatoes
are loaded into trailers or boxes. This causes tuber break-down
in localised pockets in the store, and can spread through an entire
heap in a bulk store.
"A rogue temperature reading is often not a rogue probe,
but an indication of trouble in store. But the first sign of trouble
in a store is usually the smell. Any rotting tubers will need to
be ventilated thoroughly and, if possible, cooled quickly. Storage
life will inevitably be compromised by soft rot." advises
Otherwise conditions have brought a very healthy-looking crop into
most stores this season, he reports. "There was enough rain
to keep some soil on the web, so bruising is not a problem. But
it has been dry enough to ensure potatoes are fairly clean and generally
sound for storage."
For fresh and pre-packed outlets, the emphasis now is to keep diseases,
such as black dot, to a minimum. "Recent BPC research at
Sutton Bridge has shown a fast temperature pull-down helps preserve
skin finish and keeps black dot in check. Get the fans on, get the
moisture off the crop and cool it down. Once it is at the desired
temperature - 2.5 to 3.5°C- keep crop quality closely
monitored so there are no surprises at unloading."
More advice and the latest storage bulletin can be found on the
BPC website www.potato.org.uk, while growers and store managers
with specific queries can call the BPC Storage Advice Line's
freephone number on 08000 282111.
for tuber blight sting, warns British Potato Council