Rot in a few potatoes in a warehouse can spread to the whole crop. (Peter Griffin)

For the second year in a row, wet weather late in the year is prompting P.E.I. potato growers to watch their warehouses carefully.

"You'll know it when you smell it," Elmsdale farmer Peter Griffin told CBC News of what farmers are looking for.

"Rotten potatoes, they stink."

Last year, crop insurance paid out $15 million to growers because of losses due to heavy rains. This year looks just as bad.

Griffin is checking the temperature and humidity in his company's warehouses every day in the hopes of stopping problems before they start. This year's crop was hit not only by rain. The delays caused by thick mud in the fields also led to frost damage.

"Every grower I've talked to has experienced the same problems that we're experiencing on our farm," said Griffin.

"There's a lot of rot showing up, a lot of water damage showing up that we couldn't see when we were digging the potatoes. So I think every farmer on P.E.I. is sitting on pins and needles for the winter."

Griffin says he's already heard about a grower who lost 900,000 kg of potatoes.

Greg Donald, general manager of the P.E.I. Potato Board, is hopeful that with the bad weather coming later in the season this year the potatoes might store a little better.

"There have been some issues across the Island with storages but overall, all things considered, the crop has been keeping very well," said Donald.

Close to 70 per cent of the Island's potato acreage is insured. Insurance will pay out some of the value of the crop to farmers, but not what they could get on the open market.