If you run cattle in the fescue belt, there’s a good chance fescue toxicosis is harming your herd and your pocketbook. Seedhead suppression with Chaparral herbicide is a new management approach developed by Corteva Agriscience, Agriculture Division of DowDuPont to help manage fescue’s toxic impact.
Chaparral™ herbicide provides specialized broad-spectrum weed, brush and grass management. Chaparral is the simple answer for several significant, unique needs, such as reducing the impact of toxic fescue through seed-head suppression. Best of all, when you manage fescue toxicosis with Chaparral, you also control a broad spectrum of broadleaf weeds, including winter annual weeds and other early season broadleaves — such as buttercup, poison hemlock, biennial musk, bull and plumeless thistle, wild carrot and buckbrush.
Stockers benefit from fescue management — Bob Hall, Kentucky
Chaparral provides control of many broadleaf weeds that other herbicides miss, including pigweed, hoarycress (whitetop), buckbrush, biennial thistles (including bolted musk thistle), Missouri goldenrod, wild carrot, giant hogweed and many others.
Improves animal health and performance when used to suppress Kentucky 31 tall fescue seedheads.
Increased desirable grass production.
Soil residual activity controls new weeds that can emerge in multiple flushes throughout the grazing season.
The best and most-consistent option for clearing buckbrush.
Provides the best pigweed residual and blackberry control.
Apply 2 ounces of Chaparral™ herbicide per acre for effective weed control along with seedhead suppression.
Apply Chaparral as early as three weeks prior to seedhead emergence and as late as the early boot stage, with later applications preferred over earlier applications.
Expect a lag phase (grass yellowing) for at least two weeks.
Do not use liquid fertilizer as a carrier when applying Chaparral for seedhead suppression; doing so may further exacerbate grass yellowing.
Anticipate reduced biomass and increased forage consumption due to the reduction of seed heads and stems, and then adjust grazing programs accordingly.
Consider treating half your tall fescue acres or less; graze the untreated fescue up until seed-head emergence and then rotate to the treated fescue, which will remain vegetative through fescue’s summer slump.
Remember: Research shows reduced biomass is offset by increased livestock gains.
Only a fence and herbicide treatment separate these two calves, but there’s a big difference in their health.
The slick calf on the left grazed fescue treated with Chaparral herbicide;
the calf on the right with the longer hair coat grazed untreated fescue.
Performance Metric | Effect on Production |
| Pregnancy rates | Decreased 15 to 40 percent |
| Milk production | Decreased 25 percent |
| Weaning weights | Decreased 65 to 85 pounds |
| Time spent grazing | Decreased 20 percent |
| Forage intake | Decreased 25 to 40 percent |
| Average daily gain | Decreased 0.3 to 1.2 pounds per day |
| Water usage | Increased 25 percent |
| Body temperature | Increased 1 to 4 degrees |
‡Patterson et al., 1994.
Data derived from multiple research trials where pastures contained 70 percent or more endophyte-infected tall fescue.
Effect of seedhead suppression on stocker cattle and forage quality of pastures grazed. Data was collected from 2009 through 2012 on three separate studies conducted by the USDA-ARS Forage Animal Production Unit.¥
Treated with Chaparral™ herbicide | Nonsuppressed seed heads | |
| 2009 to 2010 | ||
| Steer ADG | 2.1 pounds | 1.48 pounds |
| Crude protein | 14.4 percent | 11.6 percent |
| In vitro dry matter digestibility | 78.6 percent | 71.7 percent |
| 2011 to 2012 | ||
| Steer ADG | 2.1 pounds | 1.74 pounds |
| Crude Protein | 14.2 percent | 9.9 percent |
| In vitro dry matter digestibility | 72.2 percent | 66.4 percent |
| 2013 to 2014 | ||
| Steer ADG | 2.9 pounds | 1.96 pounds |
| Crude Protein | 18.6 percent | 14.8 percent |
| In vitro dry matter digestibility | 76.1 percent | 72.6 percent |
¥Aiken et al., 2012; Goff et al., 2012a; Goff et al., 2012b
Effect of seedhead suppression on 205-day adjusted weaning weights of calves and breed back of cows.
Location | 205-day Adjusted Weaning Weight | Cow Pregnancy Rates | |||
| Treated | Untreated | Difference | Treated | Untreated | |
| Farm 1 | 473 pounds | 418 pounds | +55 pounds | 95 percent | 80 percent |
| Farm 2 | 483 pounds | 463 pounds | +20 pounds | 95 percent | 70 percent |
| Farm 3 | 476 pounds | 459 pounds | +17 pounds | Equal at 91 percent | |
*Heavy spring grazing on treated and untreated paddocks resulted in seedhead suppression through grazing. Thus, the untreated paddock behaved similarly to the suppressed paddock. Adapted from Boyer et al., 2015.
Data was collected from three different locations owned by Whitesell Land and Cattle Co. At each location, the pastures were split into two paddocks so that half the herd would be on a paddock treated with Chaparral™ herbicide (tall fescue, seed heads suppressed), and the other half would be on a paddock treated with GrazonNext® HL herbicide (nonsuppressed seed heads).
