Re: [globalnews] Knapweed may hold key to creating effective,natural herbicide
Title: FW: [globalnews] Knapweed may hold key to creating effective, natural herbicide Jane, This can also be looked as a better long term plan for farmers transitioning away from chemical agriculture. It is difficult for our large scale agronomical systems to cut off chemicals abruptly... a non-synthetic chemical herbicide may help control weeds during the transition time.. and actually speed that transition if it allows more biological life to survive. As the author mentions... hope it spurs more research... maybe too optimistic, huh? Perry (More reductionist research...JS) Knapweed may hold key to creating effective, natural herbicide By Katherine Vogt, Associated Press DENVER An invasive weed that has taken over vast swaths of grazing land in the West may hold the key to creating an effective, natural herbicide.
FW: [globalnews] Knapweed may hold key to creating effective,natural herbicide
Title: FW: [globalnews] Knapweed may hold key to creating effective, natural herbicide (More reductionist research...JS) Knapweed may hold key to creating effective, natural herbicide By Katherine Vogt, Associated Press DENVER — An invasive weed that has taken over vast swaths of grazing land in the West may hold the key to creating an effective, natural herbicide. A Colorado State University study found that a chemical compound secreted from the roots of spotted knapweed is toxic to surrounding plants and has potential to wipe out other unwanted weeds. "This is a herbicide that is as potent as a commercial chemical but it comes from a natural plant," said study author Jorge Vivanco, an assistant professor of horticulture biotechnology at CSU. "It's considered an environmentally friendly herbicide." Vivanco's research — and a separate study at the University of Colorado in which bugs stopped the spread of diffuse knapweed — are among the latest efforts to find natural ways of controlling invasive plants that have bedeviled farmers and ranchers for centuries. Eric Lane, who carries the unlikely title of "state weed coordinator," says there is a growing emphasis on nonchemical ways to fend off weeds. He called the knapweed study exciting because it would encourage others to try similar efforts. At least three knapweed species are found in Colorado, and forms of the invasive weed have taken over millions of acres in the West. The plant is capable of wiping out all other surrounding plants, effectively ruining grazing lands. Because they are not native to Colorado, they have few predators. Originally from eastern Europe and western Asia, the most common knapweed species in the West are believed to have arrived in the late 1800s in contaminated crop seed or possibly discarded soil from ships. Common forms feature tiny white or purple flowers on spindly, leafed green stalks. Two years ago, Vivanco read about a knapweed species that invades and colonizes by secreting a toxic compound into the soil through its roots. His team tried to become the first to isolate the chemical from spotted knapweed — a feat complicated by the complex jumble of contaminants, microbes, and chemicals found in soil. The team grew spotted knapweed plants in flasks in the lab. The roots were submerged in a water-based solution while the plant floated on top. The plants secreted the toxic chemical compound into the liquid, making it easier for the researchers to isolate each compound in it. They found nearly 30 compounds, including two forms of catechin. One type had antibacterial properties, and the other had a toxic effect on other plants. The researchers found that spraying toxic catechin on plants or adding it to soil was as effective against some weeds as common synthetic herbicides, typically killing the plants within a week. Vivanco said no one previously knew about catechin's toxic effect on plants. His findings were published last year in the journal Plant Physiology . Because there is no evidence that catechin is toxic to humans or animals, Vivanco hopes it will eventually be fast-tracked for approval by the Environmental Protection Agency. CSU has licensed the catechin technology patent to a company, and Vivanco hopes to see it on the market in two or three years. Ragan Callaway, an associate professor of biology at the University of Montana and a plant ecologist who specializes in invasive weeds, said Vivanco's research is exciting but should be carefully studied. "Just because it's produced organically doesn't mean it won't kill you. On the other hand, I think that because Jorge is trying to use natural processes to control how plants interact with each other is fantastic," Callaway said. Vivanco said the discovery has several potential applications as a herbicide. In reduced concentrations the chemical only kills select plants while sparing others. That could allow farmers to protect a crop while killing a weed. Or it could be used as a preventive agent by mixing it with soil before weeds emerge. Source: Associated Press -- Love and compassion are necessities, not luxuries. Without them, humanity cannot survive. - HH Tenzin Gyatso, the 14th Dalai Lama
Re: Integrated Vegetative Management of Knapweed in the western states,
Thank you, Michael. I will order this publication. Today, we spread our rye, oat, barley/vetch, red and white clover seed and dug up some young tansy, knapweed and hawkweed on Rapid Lightning on a bare ditching area that was never reseeded. I also gathered 2/3rds of a quart ziplock full of knapweed seedheads up on our hill, a mile and a half off the road to get the seeds to make pepper. I did not get much seed and stopped trying. I found 11 larvae or pupae and got an average of 1 seed per seedhead opened. A lot of the seedheads were empty of seeds altogether. Just a couple had their full contingent of seed. I had the same experience when I gathered knapweed seedheads at the end of the road about five miles down the road from our hill. Agapeta sp. are all over this area, it seems. We have a friend who lives off the road on Sunnyside who has lots of knapweed in his yard. I will try there next. It is gratifying to know that an 8-year-old deployment of Agapeta is now all over the area. There has been so much turn-over in county weed supervisors and loss of records in a misguided attempt at fiscal responsibility by previous commissioners that no one had checked on the biological controls for knapweed until last year when I opened a seedhead in front of the Weed Supervisor and found a larva. I don't even know if future county commissioners would understand the significance of the widespread presence of Agapeta larvae and pupae on Rapid Lightning Road. Just this in itself seems like a good reason to me to keep the herbicide off this road. However, we will control spotted knapweed and the other weeds promised in our grant application on the right-of-way as we have understaken to do. Merla mroboz wrote: > Dear Idaho lady and others who are interested, Some time ago, there > was much discussion on knapweed management and one woman was appearing > before before very scarry panels. :Here is some info. that might be of > use that just came today in the mail: "Integrated Management of > Knapweed", Isa Woo, Tanya Drlik, Laurie Swiadon and William Quarles, > in the IPM Practitioner, vol; XXIV, #4, Apr. 2002. Most of this issue > is about monitoring, treatment thresholds, prevention physcial > controls, mowing and cultivation, grazing with sheep and goats, and > biological control with larva of certain moths and beetles.I know > the the BWC, Biological Weed Control, a commercial enterprise in > Bozeman, MT. was working on biological controls of knapweed and other > obnoxious weeds. To obtain this publication, write to:BIRCPO Box > 7414, Berkeley, CA, 94707510-524-2567,/ 510-524-1758 fax Hope this > helps some,Cheers, MichaelN. Vanc., BC, Canada
Intgrated Vegetative Manageent of Knapweed in the western states,
Dear Idaho lady and others who are interested, Some time ago, there was much discussion on knapweek management and one woman was appearing before before very scarry panels. :Here is some info. that might be of use that just came today in the mail: "Integrated management of Knapweed", Isa Woo, Tanya Drlik, Laurie Swiadon and William Quarles, in the IPM Practitioner, vol; XXIV, #4, Apr. 2002. Most of this issue is about monitoring, treatment thresholds, prevention physcial controls, mowing and cultivation, grazing with sheep and goats, and biological control with larva of certain moths and beetles. I know the the BWC, Biological Weed Control, a commercial enterprise in Bozeman, MT. was working on biological controls of knapweed and other obnoxious weeds. To obtain this publication, write to: BIRC PO Box 7414, Berkeley, CA, 94707 510-524-2567,/ 510-524-1758 fax Hope this helps some, Cheers, Michael N. Vanc., BC, Canada
Knapweed
At 12:02 PM 4/4/02 -0500, Tony wrote:
Is
Merla's knapweed the same as ours in Britain - Centaurea scabiosa or C.
nigra (also known as Hardheads ?
Names are confusing.
Spotted knpweed is Centaurea maculosa
"Hardhead" is sometimes used as common name for C.
macrocephalea, one of my favorite garden flowers. well behaved tho it has
thugish cousins.
I have it
occasionally in a rough lawn on an old cinder patch but don't find it at
all invasive (it can easily be mown out). It is, indeed, attractive
and valuable as the major food-plant of cinnabar moth larvae ('football
jersey' caterpillars).
Tansy ragwort Senecio spp. is the host for cinnabar moth, at least over
here.
not to be confused with common tansy Tanacetum vulgare
==
Dave Robison
Knapweed
Is Merla's knapweed the same as ours in Britain -
Centaurea scabiosa or C. nigra (also known as Hardheads ? I have it
occasionally in a rough lawn on an old cinder patch but don't find it at all
invasive (it can easily be mown out). It is,
indeed, attractive and valuable as the major food-plant
of cinnabar moth larvae ('football jersey'
caterpillars). Tony
N-S.
