5 December 1997

Minimise store damage with breath of fresh air

KEEP ventilating potato stores to prevent diseased or damaged tubers degenerating and putting the entire crop at risk, say storage experts.

"A lot of moisture comes in with the crop and some permeates through skins," says Anglian Produces agronomist Simon Bowen. "So blowing air through the store is particularly important this year. It will prevent a handful of rot-prone tubers from causing a lot of trouble later on."

Overall the 1997 potato crop went into store in good condition, he says. Despite earlier concerns tuber blight does not seem to have materialised – in the east at least.

But the dry harvest caused the worst bruising, particularly in the drier east, for several years.

"Another unusual feature of the season is the early break of dormancy. Often after a hot dry summer the dormancy period is reduced so growers should watch out for early sprouting, particularly in a variety like Piper which has a short fuse."

Of the skin diseases black dot, which is not usually a problem, is widespread this season, possibly due to the wet June. Little can be done to control it, apart from dry curing and reducing the temperature of stored packing crops to 3-4C as soon as possible.

Black scurf is also widespread, reaching serious levels in some stores. Infection from soil on farms where potatoes are grown in close rotations may be to blame.

Fenmarcs consultant agronomist Roger Ward is pleased with the quality of this seasons stored crop. He had feared blight, but knows of no cases where infection has caused trouble.

"But I have seen black dot where a lot of irrigation was done, and some black scurf due to high August temperatures," he says. "Both are on-going diseases which will be present when stores are unloaded."

SPUD STORES

&#8226 Blow to remove moisture.

&#8226 Check store regularly.

&#8226 Blight rare so far.

&#8226 Black scurf and black dot more common than usual.

Ventilation prevents diseased/ damaged tubers causing wider rotting in stores. Black dot and black scurf are additional problems growers face this year.