Potato growers need to assess the risk of dry rot to their crop and seed producers should be on the look-out now for signs of the disease as they grade-out stocks, is the advice from the British Potato Council. A new BPC guide has been issued to levy-payers to help them identify problems in store and the actions needed to minimise the threat of the disease developing.

Fusarium coeruleum - the most common form of dry rot in eastern and northern England.

“Dry rot is the most significant fungal rot of potatoes in Great Britain and affects around 1% of tubers annually,” advises BPC plant pathologist at Sutton Bridge, Jeff Peters. “Seed suppliers should be assessing the likelihood of rot developing in their stocks, especially susceptible varieties, such as Hermes, Estima and Maris Piper. Ware growers should consider the risk of rot when they source their seed.”


There are three key questions for growers, says Dr Peters:

• Are your varieties susceptible to dry rot?
• Is dry rot control a priority for your seed supplier?
• Have you had rot problems in the past that you've put down to blackleg or blight?

“The true cost of dry rot to the industry remains a mystery because it enables Erwinia species to colonise and develop into soft rots. But there are some simple steps that can be taken to reduce the incidences of the disease.”

Seed suppliers should start by hot-boxing samples at temperatures above 10°C. “A new, easy-to-use but comprehensive guide on dry rot has just been distributed to BPC levy-payers that will help them identify the disease and the action they should take. For those who need to treat tubers, we're strongly advocating using a tank mix of imazalil and thiabendazole to overcome any resistance issues,” recommends Dr Peters.

Seed growers should also consider store hygiene as they grade stocks out of their stores. “One of the major issues to address is multiple handling. Grading in store can increase the spread of contaminated dust. Our advice is aim to grade stocks just once as the store is loaded. This also decreases the risk of bruising damage.”

For more advice on store hygiene growers should refer to the BPC Store Hygiene CD - further copies are available by e-mailing publications@potato.org.uk or by calling 01865 782222. For specific queries on dry rot or other storage issues, call the Storage Advice Line free on 08000 282111.

• The BPC Store Managers Course takes place on February 9 and 10 2006 at the Three Counties Hotel, Hereford. Pre-booking is essential. Call Sutton Bridge Experimental Unit on 01406 351444 for further details

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