Solutions: Weapons in the War

Even after the contract with the Nez Perce National Historic Park is completed, phantom spines still prick my hands, as well as my anger.  As if a spine has broken off in my flesh and begun to fester, my awareness of yellow star thistle grows, as does my desire to better understand it.   Intro paragraph

I am not the only one who is haunted by images of hillsides gilded yellow by star thistle, however. Other people feel this phantom spine, too. Dr. Linda Wilson is among those searching to understand yellow star thistle and how we can best combat it. A slight, older woman with glasses and tidy gray hair, Wilson seems quite at ease the day I spoke with her in her office in the College of Agriculture at the University of Idaho. We are dwarfed by the rows of bookshelves along the walls of the narrow room, holding volumes of research data and notes on hawkweed, yellow star thistle and other noxious weed cousins, as well as more common publications, like Weeds of the West. A plaque rests on one of the bookshelves, awarded to Wilson in  1999, for being one of the top graduate students in her field. A fresher reminder of her work leans against her desk: a brown paper bag stuffed with dried specimens of spotted knapweed and yellow star thistle. ç characterization, place and main point of the section

Listening to Dr. Wilson recount one of her first experiences with yellow star thistle, my own grudge seems almost petty by comparison. In her soft-spoken way,<characterization> she tells me of how, before she was a research scientist for the College of Agriculture, she worked for the U.S. Forest Service in Okanogan County, Washington. While she was a federal employee, the USFS aerial-seeded 2500 acres of private land after a fire: The grass seed they bought, however, was not certified weed-free.  So, the USFS ended up spreading yellow star thistle over 2500 acres, an area where it had not previously existed. <narration

 “I had to organize the hand pull and horse crews,” she recalls quietly.  “The terrain was hilly and partially forested. We spent weeks trying to locate and pull it all.  We bagged them, we bummed them. It was hot and frustrating. We spent so much effort, but we could never find them all.” (Wilson, 2001) <narration The utter irony and frustration of the entire situation can be heard in her voice, helping to crystallize the image in my mind. <analysis/connection to author's experience

Both my crew and Linda Wilson's crew attempted to erase yellow star thistle from the land by hand alone. Hand-pulling contributes to some of the most gruesome experiences and some of the worst battle scars in the war on this noxious invader. As Wilson recalls, "I've worn shorts on hot days and paid dearly for it. I've worn out half-a- dozen pairs of pants, thrown away socks and shoes infested with cheat grass. . .even leather pants can't withstand it" (Wilson, 2001).<use of quotes to make experience "real."> Clearly, hand-pulling is not for the faint of heart. <analysis>

But hand-pulling is also not always the most effective way to eradicate yellow star thistle.  <introduce> Dr. Wilson admitted they probably missed a good portion of the star thistle they were looking for on those 2500 acres.  Hand-pulling can be an effective process, but only in certain conditions. <facts from INTERVIEW>  In large patches, it is neither efficient nor cost-effective to wade through fields of star thistle, plucking each plant out by hand. However, if the star thistle plants are young and few in  number, hand-pulling can be one of the most important ways of controlling it. This process is most appropriate when the plant can be pulled without leaving a crown and roots behind to resprout (Callihan,  1995, p. 2). <facts from SOURCE> Yellow star thistle is notorious for its deep taproot, allowing it to find water in some of the driest conditions, and also making hand-pulling a difficult task.<author's ANALYSIS>

There are many other alternatives to hand-pulling yellow star thistle, however. <introduce/transition> Among these are mowing, herbicides, prescribed burning, and biological controls, which include grazing, insects and vegetative competition. (Lass, 1999, p. 9). They have all been tested in one form or another and some have proven more effective than others.  Mowing yellow star thistle has proven one of the least effective methods of control. It does as little or less good than pulling by hand, as it leaves the taproots and side branches to regrow later on. Mowing may impede growth, but it will not stop reproduction. (Callihan, 1995, p. 3) <facts from sources/synthesis>

Herbicides are a common favorite for controlling all sorts of unwanted weeds in our backyards as well as on our rangelands. <introduce> They can be quite effective in short-term control of yellow star thistle.  Numerous guides have been published by agencies, governments and universities to help landowners understand the uses and applications of different herbicides on yellow star thistle. A few of the herbicides currently in use include 2,4-D, dicamba (Banvel), clopyralid (Curtail has clopyralid with 2,4-D) and picloram (Tordon 22K). While applicators are held liable for the improper use of any herbicide, picloram, in particular, requires special licensing and training to purchase and use it (Callihan, 1995, p. 3). <facts from source>

Herbicides can work effectively in those places where mechanical removal is difficult or impossible, like on very steep hillsides or growing along sidewalks and in parking lots.  There are certain drawbacks, however.  The most effective herbicides are also effective against desirable plant species and can endanger water quality (Callihan,1995, p. 3). While herbicides wipe out yellow star thistle in many instances, some star thistle exhibited resistances to chemicals like picloram (Sterling, 2001, p. 44).  It is possible, under continued applications of picloram, for a field of yellow star thistle to be reduced to only those plants that have a resistance to it.  If those star thistle plants spread their seeds to other locations, an even more serious problem could develop (Sterling,2001, p. 44). <synthesis/analysis>

Herbicides are a short-term solution, however. <introduce>Spraying may eradicate the weed, but nature abhors a vacuum; if you don't replace the weed with a more beneficial plant, another noxious cousin will just move right in (Wilson, 2001). Wilson pointed out to me matter-of-factly, "Small landowners can spray until they're blue in the face, but they will not get a sustainable outcome if they don't alter their behavior" (2001). By behavior, she means abuse of resources, like over-grazing a pasture. <facts>Grass that has been thoroughly trampled and over-grazed isn't healthy enough to compete with yellow star thistle sprouts and the entire pasture is bound to be overtaken by glowing "yellow star." When humans get sick, we start coughing and sniffling. When pastures get sick, they turn yellow or purple, or the color of the weeds that have infested it happen to bloom in.  <analysis>

Prescribed burning, like mowing, has proven only partially effective against yellow star thistle.  While fire can reduce star thistle populations by as much as 30%- 70% and for a couple of years after a single burning, it is hardly a cure-all (Lass, 1999, p. 9).  Burning is often not recommended because of the danger of wildfire. Also, without further preventative measures, burning can produce ideal conditions for more yellow star thistle to sprout. The only way to control yellow star thistle after a burn is to use vegetative competition: seeding other grasses that will compete with the star thistle sprouts and keep them under control (Callihan, 1995, p. 3).<Facts/synthesis>

The last alternative in our arsenal of weapons is biological control. Biological control is one of the newest and "sexiest" issues in the world of weed control today. It includes grazing, insect controls and competition from grasses and forbs. (Callihan, 1995, 4).....