Wyethia with Desirable Forage Species
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Replacing Wyethia with Desirable Forage Species WALTER F. MUEGGLER AND JAMES P. RLAISDELL Range Conservationists, Intermountain Forest and Range Experiment Station, CJ. S. Forest Service, Ogden, Utah ENSE stands of wyethia (Wyethia DRY CREEK STUDY D amplexicaulis and W. helianthoides) Methods now occur on extensive areas of western mountain range lands (Fig. 1A). These A 14-acre area on Dry Creek, approxi- plants prefer moist, heavy soils, and mately 6,500 feet in elevation and sloping consequently are found on some of the gently to the southeast, was selected in most productive sites. An air-dry herbage 1947. The annual precipitation is prob- production of more than 1.5 tons per ably between 20 and 25 inches, and the acre is possible on many of these sites, soil is a heavy, black loam. Prior to but when most of this is made up of the treatment, the area supported a dense relat)ively unpalatable wyethia, there is stand of wyethia (mostly W. amplexi- only a small amount of usable forage. caulis but some W. helianthoides) with a Such stands of wyethia may be native small amount of geranium (Geranium on some areas, but on many others it is viscosissimum), cinquefoil (Potentilla sp.), thought that wyethia has increased as dock (Rumex sp.), mountain brome more palatable plants have been reduced (Bromus carinatus), slender wheatgrass by heavy grazing. Wyethia appears to be (Agropyron trachycaulum), bluegrasses long lived and a strong competitor, so (Poa spp.), oniongrass (Mel&a sp.), and that its elimination by nattiral means, if several other grasses and forbs. possible at all, is slow. In order to deter- Five methods of cultivation were used mine what methods might be successful on duplicated l-acre plots in September, in converting dense stands of wyethia to 1947: moldboard plowing to 10 inches, more desirable plants quickly, studies wheatland plowing to 3 and 6 inches, were begun in 1947 on the Spencer Dis- and offset (2-way) disking to 3 and 5 trict of the Targhee National Forest in inches. Two plots were reserved as un- eastern Idaho. treated checks. The authors wish to acknowledge the In June, 1948 one plot was plowed with assistance of Lyman Richwine, District a moldboard plow to a depth of 6 inches. Forest Ranger, in establishing and main- In addition, one uncultivated plot was taining these studies, and the work of divided into 10 sections, and four chemi- C. E. Holscher, now with the Pacific cals were applied with a hand sprayer to Northwest Forest and Range Experiment duplicated 0. l-acre sections. Ammonium Station, who planned the Dry Creek sulfamate was applied at the rate of study. They also wish to thank George 25 pounds per acre, ammonium 2,4-di- Whornham of the American Chemical chlorophenoxyacetate at 3 pounds per Paint Company for furnishing the chemi- acre, a mixture of diesel oil and creosote cals used in the West Camas Creek at 45 gallons per acre, and kerosene at study and for his advice in the selection 45 gallons per acre. The two remaining of these chemicals. sections were left as untreated checks. 144 WALTER F. MUEGGLER AND JAMES P. BLAISDELL Plots cultivated in the fall of 1947, as 1). In 1948 it appeared that plowing in well as the untreated check plots, were the spring was considerably more effec- broadcast to a mixture of smooth brome tive than in the fall, but these initial (Rromus inermis) , slender wheatgrass, differences had mostly disappeared by timothy (Phleum pratense), and orchard- 1950. Although there was only a slight, grass (Dactylis glomerata) at the rate of difference in favor of spring plowing in 10 pounds per acre immediately after 1950, cultivation at t)his season may actu- cultivation. The spring-plowed plot and ally be more effective as these results t’he chemically treated sections were were accomplished by plowing at’ a 6-inch drilled to the same mixture in the fall of depth, whereas the fall plowing was at 10 1948. inches. Disking with a wheatland plow TABLE 1 E$ects of cultural and chemical treatments on numbers of wyethia and air-dry production of wyethia and grass, Dry Creek HERBAGE PRODUCTION WYETHIA PLANTS PER (Percent of check) SUBPLOT (Percefit of check) TREATMENT AND SEASON Wyethia Grass -/- I-1948 1949 1950 1949 1950 Yawing: Sprir& moldhoard, g-inch depth. 17 25 24 19 18 75 53 Fall moldboard, lo-inch depth.. 44 39 26 20 23 749 1365 Fall wheatland, 6-inch depth. 102 107 175 128 126 62 66 Fall wheatland, 3-inch depth.. 122 111 156 113 110 73 80 Fall offset disk, 5-inch depth.. 92 85 109 101 80 93 100 Fall offset disk, 3-inch depth. .. 125 114 161 124 122 82 104 -~--------~~ --- --- --- --- _--- --- Untreated check (number and Ibs. per acre). 47 46 44 2069 1376 186 167 _~___--_-_-~~ -- -__ --- --- _---- --- Chetiical treatment: 2,4-D’................... - 58 36 22 31 171 326 Kerosene................. - 87 98 79 107 92 74 Creosote and diesel oil. - 87 93 85 95 63 86 Ammonium sulfamate. - 83 101 77 96 130 162 --- --- __- --- -__ _-__- Untreated check (number and lbs. per acre). - 56 58 3080 1612 100 l Ammonium 2,4-dichlorophenoxyacetate. Wyethia plants were counted on cir- and an offset disk was not effective at cular 4%square-foot subplots within each either depth. As a matter of fact, wheat- acre plot during late summer of 1948, land plowing at both depths and shallow 1949, and 1950. Weight estimates were offset disking resulted in a substantial made of both wyethia and reseeded increase in plant numbers and a similar, grasses in 1949 and 1950. though less pronounced, increase in wyethia herbage. Apparently the disks Results cut the taproot so shallowly that in Moldboard plowing was the only many cases both sections of root con- method of cultivation which caused an tinued to grow, producing two plant)s appreciable reduction in wyethia (Table instead of one. The inadequacy of offset disking wits further subntantint~d hy hers were essentially the same as on the poor results obtained from disking a untreated checkrj. 5-acre area on West Camas Creek in the Of t,he grasses broadcast in the fall of spring of 1949. 1947, s successful stand was obt,ained A critical examination of data in Table only on t,he fall moldboard-plowed plots, 1 shovs certain variations h&wren years ix., only &here wyethis had hren greatly for \vhivh no explanation is readily ap- reduced. Grass production on these plots parent. It, is thought that these minor WRS over seven times that of t,he un- variations arc attrihutahle to sampling treated plots in I919 and over thirteen error resulting from use of different times, in 1950. Total grass production sample subplots rach yciu. \~as decreased on all other plots, but Wyethia herbage production ras those treated rith the offset disk had greatly reduced the year following treat- reoovered sufficiently to pro&we as ment with 2,4-D (Table l), and numbers much as the untreated plots by 1950. of plants continued to decrease the second Three years after fall moldboard ploving year after spraying. Both herbsge pro- and reseeding, grass production was over duction of wyethia and numbers of plants 1 ton of air-dry herhage per acre, whereas were slightly decreased by the other wyethia was producing less than 14 per- chemical treatments, but these decreases cent of this amount. This relatively small were only temporary, for in 1950 both amount of wyethia grew in roes at the wyethia herbage yield and plant num- edges of furrows where roots were not 146 WALTER F. MUEGGLER AND JAMES P. BLAISDELL completely sheared and turned. In con- sp.), dock, geranium, cinquefoil, dan- trast to this, other fall cultivated plots delion (Taraxacum oficinale), yarrow were producing between 1,000 and 2,000 (Achilles lanulosa) , yampa (Perideridia pounds of wyethia and less than 200 gairdneri) , and others. pounds of grass. These differences are Effectiveness of three herbicides for well illustrated in Figure 1B. wyethia eradication were tested at two Although a good kill of wyethia was rates of application at two dates (growth obtained on the spring moldboard-plowed stages). In order that regular field meth- area, the establishment of grass was un- ods of spraying could be employed, 0.5- successful. This grass failure was prob- acre plots, each 1 by 5 chains, were used. ably not related to season of plowing but All treatments were duplicated and perhaps to less favorable weather follow- there were four untreated check plots. ing the 1948 planting or too deep seed Treatments were assigned at random to covering through drilling. the plots within each replication. Grass production was greatly increased Commercial formulations were used on the sections treated with 2,4-D, and throughout. These consisted of a 2,4-D to a lesser extent, on those treated with ethyl ester, a 2,4,5-T butoxy ethanol ammonium sulfamate. This increase, in ester, and a mixture of two parts 2,4-D contrast to that on the fall moldboard- and one part 2,4,5-T in butoxy ethanol plowed plots, was mostly due to an in- ester form. Rates of application were 1 crease in natjive grasses, rather than to and 2 pounds acid equivalent per acre, establishment of reseeded species. Ap- and application was made at two growth parently the hard, uncultivated ground stages, when the wyethia was about was such a poor seedbed that reseeded half way through blooming (June 7) and grasses were unable to become established when blooming was over (June 20, 1949).