Rot risk rises as stores settle
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Potato growers must stay vigilant and handle stored crops carefully to avoid the risk of rots developing, the British Potato Council has warned.
As harvest progresses, reports indicate that the quality of crops that have already come into store is better than had been anticipated. But there is potential for serious problems, especially in poorly-managed stores, notes Jeff Peters from BPC's Sutton Bridge Experimental Unit (SBEU).
"Many crops will now be nearing long-term holding temperature. This is the danger zone where there is a high potential for rots to develop," he says.
Key to keeping crops in good condition will be adequate ventilation, careful temperature pull-down and close monitoring. "You must avoid hot spots and condensation developing. Make sure you stack or load the store to ensure good airflow and ventilate correctly. Watch for carbon dioxide build-up – this will affect crop quality, while anaerobic store atmospheres will bring on rots," advises Dr Peters.
Warm, wet conditions are needed for the soft rot bacteria, Erwinia species, to cause tuber breakdown. Fungal diseases, such as tuber blight, often allow the bacteria to gain a foothold. High levels of rots were feared following the wet summer. But SBEU believes a dry October has ensured a much healthier crop than was initially expected is now coming into stores. Nor have crops broken down as badly as expected.
"Monitoring will be crucial – during the critical first few weeks of storage, it is vital that ventilation continues until the crop is completely dry," Dr Peters advises.
The BPC has introduced a special seminar on storage at British Potato 2007, taking place in Harrogate on November 28 and 29, to help growers ensure maximum value from their stored crop in a difficult season for storage. Go to www.potato.org.uk/bp2007 for details. For more advice on rots and other topical storage issues, see the latest Storage bulletin at www.potato.org.uk/sbeu. The BPC's Store Performance Guide contains guidance on loading and ventilation – call BPC Publications on 01865 782222 (line is open 24 hours) or e-mail publications@potato.org.uk
