Palmer amaranth has caused corn, soybean and cotton farmers a world of trouble.

Now, tobacco farmers may be in danger of a big loss due to the weed.

That's because their No. 1 customer, the People’s Republic of China, says it has found seeds of Palmer amaranth and other weeds it doesn’t like in tobacco leaf they have bought here. They don't want any more.

"The Chinese do not tolerate invasive weed seeds," said Peter Thornton, assistant director for international marketing with the North Carolina Department of Agriculture.

“We need to provide a solution to this problem.  China is the largest potential growth market we have.”

The objectionable infestations— which also included crabgrass and foxtail — were discovered by the Chinese national quarantine agency. 

This appears to be a bigger problem in mechanized flue-cured harvest than any form of hand harvest.

“We think the problem occurs mainly where you are trying to mechanically harvest in the presence of big weeds,” said Matthew Vann, North Carolina Extension tobacco specialist.

That's why one of the Extension recommendations is that you keep the field border clean and mowed so you don't take any weed seed in with you, he said.