With five to 10 per cent of the P.E.I. potato crop destroyed by rain, growers have to adopt strict new sorting regulations to ensure more potatoes aren't damaged in storage.

Record rainfall in August — triple the average — followed by the remnants of Hurricane Hanna in early September left many fields underwater, and the submerged crop destroyed. But many fields have a combination of good potatoes and damaged ones.

P.E.I. Potato Board chairman Kevin MacIsaac told CBC News on Tuesday that putting damaged potatoes in with good ones could spread rot.

"We're going to be separating out any tubers that aren't storable," said MacIsaac.

"There is going to be some extra time, effort and labour involved, which all adds to more costs in the harvesting process."

Buyers, in particular local processors, are also getting involved in meetings with growers to advise them on proper procedures.

MacIsaac said there are also reports of "hollow heart" in some potatoes, a condition in which the tubers grow too fast, leaving them hollow on the inside.

Recent drier weather is benefiting some of the late varieties of potatoes, MacIsaac said. Most growers should start harvesting this week or next.