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?
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 firstname.lastname@example.org 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
for rots as potato stores fill
for tuber blight sting, warns British Potato Council
crops face blight threat warns BPC