Canada thistle has surpassed leafy spurge as North Dakota's peskiest weed, state agriculture officials say.

"Slightly more than 1 million acres are infested with Canada thistle, according to reports received from North Dakota's county and city weed boards and land managers," Agriculture Commissioner Roger Johnson said in a statement. "The total for leafy spurge is about 861,000 acres."

The department said the numbers are based on a survey last year. It showed other top weeds in the state were absinth wormwood with 609,100 acres, field bindweed with 417,600 acres, and musk thistle with 25,400 acres.

Dalmatian toadflax, diffuse knapweed, purple loosestrife, Russian knapweed, saltcedar, spotted knapweed and yellow starthistle had total infestations of less than 2,500 acres, the agriculture department said.

In Cass County, the weed control board is offering to reimburse some of the costs of controlling Canada thistle. It is the third year of a county reward program to help control weeds.

Associated Press