The soggy spring has postponed spring planting for many farmers, but promises a healthy crop of the much maligned musk thistle unless property owners act swiftly to kill the plants.
Dave Leuty, Douglas County's noxious weed director, said the spiny weeds topped with a purple flower pose an annual problem, and rainy conditions only aggravate the situation.
"They really thrive in a wet spring like this," he said. "Some of those seeds can lay dormant for up to 20 years and when we get wet weather, they go ahead and germinate."
The county combats the noxious weed on county right of ways by mowing and spraying with Tordon 22-K and 2,4-D. Leuty said his office also sells the chemicals and rents sprayers to rural landowners.
Bill Scott, weed specialist with the Kansas Board of Agriculture, said the rain not only encourages growth of the musk thistle it also impedes efforts to control the weed.
"Because of all the rainfall we're having, it's very difficult for people to get in the fields and pastures to do any kind of control," he said.
Scott said he encourages the use of herbicide treatments in the fall and promotes other measures at this time of year. He said landowners still can spray herbicides in the spring, but heavy rains will decrease the effectiveness and the chemicals could kill the larvae of weevils that attack the musk thistle.
The state has maintained an active bio-control program for the last five years, releasing weevils in areas of high thistle infestation, said Scott. The musk thistle head weevil first was introduced in 1979 to a number of counties in the northeastern and north central parts of the state. In the early 1980s, Kansas State University released the rosette weevil, which has been increasing in numbers.
The head weevil lays eggs on the base of the flower head and the larvae feed on tissue that nourishes the seeds, rendering the seeds sterile. The rosette weevil lays eggs on the newly emerged plant, and the larvae burrow into the growing tip of the plant.
"We're seeing some results," Scott said. "I feel we're getting it under control."
Musk thistles are illegal in Kansas, so property owners who fail to control the weed's growth face a fine of $50 to $500, said Leuty.
When Douglas County receives complaints, the landowner is sent an informational letter explaining that the musk thistle is a noxious weed and providing tips on how to fight it. If the landowner doesn't address the problem within about two weeks, the county sends an official warning by registered mail, giving the property owner 10 days to attack the musk thistle. If the warning goes unheeded, the district attorney's office issues a letter with the threat of a fine.
"Normally, after the DA writes them a letter, they take care of it," said Leuty.