MOORHEAD, Minn. (AP) - American Crystal Sugar Co. has developed a plan to plow under up to 10 percent of its sugar beet acres if the crop is so large it can't be processed by the end of May.

American Crystal told shareholder-growers of the contingency plan in a memo dated Aug. 11, saying the co-op board could order the beets destroyed in the field in mid-October.

Tom Astrup, vice president for agriculture, acknowledged Tuesday that the contingency plan has been discussed internally since May.

"The first two sets of field samples we pulled in August showed the highest tonnage we have ever seen for that time of year," Astrup wrote in the memo to shareholder-growers.

The co-op typically shoots for a 10 million-ton crop to match the processing capacity in its five plants. This year, the company is predicting 21 to 22 tons per acre on its 508,000-acre base, which would put the crop at 10.6 million to 11.2 million tons.

"It would take only "normal amounts of precipitation between now and Oct. 1 to achieve these projected yields," Astrup said.

If the crop increases to an average of 22.6 tons per acre - 11.5 million tons total - the contingency plan could kick in.

For now, growers are being asked to "mark out" 10 percent of their acres "to be left in the field until we can make a final decision," Astrup said.

Acres identified must not be destroyed or harvested before the board's decision on the plan.

"In the unlikely circumstance that we actually require you to leave some acres in the field, we will be auditing all shareholders after harvest to ensure compliance," Astrup said. Failure to comply will be interpreted as a breech of contract, he said.

There have been few complaints about the plan, but there have been "a lot of questions from growers wanting to understand the economic reasons for it," he said.

American Crystal spokesman Jeff Schweitzer said last week that the prepile harvest would start about 10 days earlier than normal - Aug. 21 in four factory districts and Aug. 26 for the East Grand Forks district. Astrup sent his letter to the growers the same day.

Full-scale harvest is set to start on the normal date, around Oct. 1. After about half of the beet harvest is completed, the co-op board will decide whether the contingency plan is necessary.

In the 1999 processing year, Crystal had to destroy about 400,000 tons of beets that had been in storage but were spoiling. However, the company's processing and storage capacities are much greater now.

While growers don't want to plow beets under, Astrup said the issue boils down to maximizing grower profit. He said it's cheaper to destroy beets in the field than it is for farmers to harvest them, haul them and for the co-op to keep them stored, only to have to pay costs to remove spoiling beets from piles and spread them back out onto the fields in the spring.