Invasive weed threatens crops
Sometimes looks can be deceiving. A pretty, tall plant, with feathery white blossoms – looking like a beautiful benign wildflower – can turn out to be a noxious, invasive weed, threatening the very bottom line of a farmer.
Tall whitetop, the bane of many farmers in the West, has found its way to the Carson Valley – and those who make their living in agriculture are concerned.
“I’m worried this is going to wipe out the Valley,” said cattle rancher and horse hay grower Clarence Burr, a fourth generation Carson Valley farmer. “If this spreads too bad, it could wipe many of us out.”
Burr said he first noticed the tall whitetop a few years ago, and since its reputation preceded it, he knows it is a fast-growing, aggressive weed that could take over his fields of high quality horse hay. For now, the tall whitetop isn’t prevalent on his property, but nearby fields threaten its spread.
“This stuff spreads fast,” he said. “Go on up on the new freeway by the Double Diamond Ranch in Reno, and you’ll see what I mean.”
n County expert on top of it. Larry Hughes, in charge of weed control for Douglas County, said he is definitely aware of tall whitetop and it is his top priority.
Hughes said he first recalled tall whitetop coming into the Carson Valley around two years ago.
“We had an old-time farmer call, wondering what was taking over his field, so we sent a sample to Reno and they took one look and said is was tall whitetop,” he said. “It was growing in the corral area, so we think it probably came in with some hay purchased elsewhere. We’ve found a lot of it in hay from Reno. I would tell people not to buy from Reno, or at least check out the fields and look closely at the hay when they buy it.”
The problem with tall whitetop is that its is very hard to kill, Hughes said. Chopping it down just stimulates the roots and rhizomes, where much if the reproduction stems from.
Tall whitetop typically spreads downstream along waterways, either through root pieces as small as 1/4-inch long or seed.
Killing it takes a few steps, but landowners who find the tall whitetop can try and treat it before it gets too widespread.
“First, you knock it down and then bag the plant and take it to the dump,” Hughes said. “Then, when the next growth comes in, we recommend using Telar on it. The key is to act fast when you first see it.”
Hughes said his department uses other chemicals on the weed, and he suggests people call him to spray because he can probably do it cheaper.
“We are willing to work with people when they find the tall whitetop, because it is such a priority for us,” he said.
Because tall whitetop grows well and is highly competitive, it crowds out other, more nutritious and diverse-for-wildlife plants. Another technique of dealing with the plant is to encourage other fast-growing plants to come in and compete, hopefully taking over after the tall whitetop is knocked down.
“Cheatgrass is a good one for that – even cheatgrass is better than whitetop,” Hughes said.
n Educate everyone. Burr said he would like everyone in the Valley to be educated as to exactly what tall whitetop, as well as short whitetop, looks like.
“I think we should put big pictures of these weeds on billboards on either end of the Valley, and say ‘Do you have any of these plants on your property? If so, call to get rid of them,'” he said. “We’re just trying to save the Valley.”
Burr said his horse hay business would collapse if tall whitetop invaded his fields. Much of his product is sold locally, but if he sells hay to California and inspectors find even one leaf of tall whitetop in the bales, the shipment will be refused and turned back to his ranch.
“This could be devastating,” he said.
n Other plants look similar. There are several wild Valley plants that can be confused with tall whitetop, Hughes said – sweet clover, yarrow, poison hemlock, Queen Anne’s lace – and all have their identifying field marks, but even ranchers get it mixed up.
“I had one long-time rancher calling me with to come and identify some whitetop, and it turned out to be hemlock, so it’s hard to distinguish,” he said.
Hughes and his seasonal crew of four have identified between 35 and 40 sites with confirmed tall whitetop. Their goal is to pay attention to these patches and eradicate them.
“We are happy to go out and identify any questionable plants for residents,” Hughes said. “All they need to do is call – we know it is hard to identify. If we can identify two or three new sites, we’re still ahead of the game. Right now we’re in the process of trying to map all the plants we see to to follow up on the treatment.”
Hughes said his department relies heavily on information from the people out in the Valley, particularly those involved in irrigation, and working around the ditches that lace the Valley.
Hughes said it would typically take three to five years to completely get rid of the existing tall whitetop. Residents who see it anywhere in the Valley – not just on their property – are urged to call Hughes to come take a look.
Patches have also been located in Smith Valley, Mason Valley, Reno and Lake Tahoe.
Other weeds on Hughes high priority list are the yellowstar thistle at the south end of Valley and the Russian knapweed, found primarily on the east side of the Valley.
Landowners who refuse to remove tall whitetop or any other noxious weeds from their property are subject to a state quarantine requiring them to do so.
“We try to avoid that,” Hughes said.
For more information, call 782-9835.