Agriculture officials have found Johnson grass, a troublesome noxious weed, in the Springville area of Utah County, but are having some difficulty convincing farmers of the threat.

"The biggest problem we have is that most people have confused quackgrass with Johnson grass, so when we talk about Johnson grass, they say, `Oh, we've dealt with that in the past and it isn't a problem,' " said F. Dean Miner Jr., Utah State University extension agent.But without early control, Johnson grass could become a very serious problem for farmers, Miner said.

The weed has the potential of cutting down production by 70 to 80 percent, he said.

"Until the plant grows higher than 4 to 6 inches, it looks just like corn. Unfortunately, it is so closely related to corn genetically, that it is impossible to control it in a cornfield with chemical herbicides," Miner said.

Miner said if a farmer finds the weed in his field, he should abandon the field for crops for at least one year and concentrate on controlling the weed.