Medusahead Control with Fall- and Spring-Applied Herbicides on Northern Utah Foothills

2005 ◽  
Vol 19 (3) ◽  
pp. 653-658 ◽  
Author(s):  
Thomas A. Monaco ◽  
Travis M. Osmond ◽  
Steven A. Dewey

Medusahead is an aggressive, nonnative, winter annual grass that infests rangelands in the western United States. Its ability to rapidly spread, outcompete native vegetation, and destroy forage potential is a primary concern for landowners and land managers exposed to this weed. Prescribed burns were conducted at a low- and high-litter site in northern Utah prior to conducting experiments to evaluate the effects of fall and spring applications of sulfometuron at 39 or 79 g ai/ha and imazapic at 70 or 140 g ai/ha on medusahead and associated perennial grasses, annual and perennial forbs, and bare ground cover. Large differences in pretreatment medusahead litter between the sites resulted in less surface area burning at the low-litter site (∼10%) compared to the high-litter site (∼80%). Higher herbicide rates significantly increased medusahead control and bare ground cover; however, this rate affect largely depended on site, season, and herbicide. The low- and high-litter sites did not differ significantly in perennial grass cover 2 yr after burning. Annual forb cover was greater, but perennial forb cover was lower at the low-litter site compared to the high-litter site. Several treatment combinations were identified as having the potential to maintain greater than 50% medusahead control in the second year after herbicide applications. These results collectively demonstrate that potential exists to successfully control medusahead and produce a window of opportunity to reintroduce a greater abundance of perennial species back into the plant community via seeding.

2009 ◽  
Vol 62 ◽  
pp. 211-216 ◽  
Author(s):  
K.N. Tozer ◽  
T.K. James ◽  
C.A. Cameron

Yellow bristle grass (YBG) which is a summeractive annual grass reduces pasture quality and becomes unpalatable to stock as panicles mature Farmers are concerned that an extreme drought from November 2007 to March 2008 may have facilitated the spread of YBG and other summeractive annual grass weeds Botanical composition was assessed on 12 Waikato dairy farms in February 2009 and YBG abundance was related to key management factors These findings were compared with data collected from the same farms (February 2008) during the drought Between years ryegrass cover and the proportion of bare ground decreased These components were replaced by two summeractive annual grasses YBG and summer grass and to a lesser extent summeractive perennial grasses clovers and dicots In 2009 YBG cover was negatively associated with summeractive perennial grass cover and pH and positively associated with YBG cover in the previous summer and soil calcium levels


2019 ◽  
Vol 12 (4) ◽  
pp. 223-228 ◽  
Author(s):  
Lindsay E. Koby ◽  
Timothy S. Prather ◽  
Harold Quicke ◽  
Jared Beuschlein ◽  
Ian C. Burke

AbstractVentenata [Ventenata dubia (Leers) Cross] is a winter annual grass relatively new to the inland Pacific Northwest that is capable of displacing desired vegetation. Indaziflam was evaluated for the management of V. dubia on two Conservation Reserve Program (CRP) sites near Moscow, ID, and Pullman, WA. While perennial grasses were dormant, applications of indaziflam in mixture with various herbicides were made in spring 2016. Treatment effects were evaluated for 2 yr by visual assessments of community composition and canopy cover of V. dubia and other non-weedy species (assessments occurred 3 to 6 mo after treatment, depending on location) and by representative cover class assessments. Biomass samples of all plant species were collected in the summer of 2017. Reduced V. dubia cover was observed in 2016, except when glyphosate was used alone. In 2017 indaziflam applied alone or in mixture with rimsulfuron effectively controlled V. dubia with minimal impact on desirable vegetation. Plant biomass from nontreated plots averaged 40 g m−2 for V. dubia and 100 to 179 g m−2 for perennial grasses. Plant biomass averaged <11 g m−2 for V. dubia and 371 to 490 g m−2 for perennial grasses when indaziflam at 102 g ai ha−1 plus glyphosate at 474 g ai ha−1 was applied. Smooth brome (Bromus inermis Leyss.) biomass was positively associated with the reduction of V. dubia, and there was a decrease in diversity associated with the removal of V. dubia through effective treatments. Indaziflam is an effective tool for the management of V. dubia in perennial grass stands, and spring applications of indaziflam should be in mixture with herbicides with POST activity.


2006 ◽  
Vol 46 (4) ◽  
pp. 439 ◽  
Author(s):  
W. McG. King ◽  
P. M. Dowling ◽  
D. L. Michalk ◽  
D. R. Kemp ◽  
G. D. Millar ◽  
...  

Temperate perennial grass-based pastures dominate the high rainfall zone of south-eastern Australia and support a major livestock production industry. This area has experienced a recent change in overall pasture condition, however, typified by a reduction in the abundance of perennial grasses and an increasingly prominent winter-annual grass weed component. Improving the condition and productivity of these pastures can be achieved by improved management but this requires better knowledge of the interactions between management options and pasture species composition and of the interaction between pasture vegetation and the complex effects of a heterogeneous landscape. This paper reports the results of an intensive survey of a 60-ha paddock that was designed to identify the species present, determine their patterns of distribution and examine the relationships between pasture vegetation and the environment. The survey of species present in late summer was supplemented by the identification of seedlings that later emerged from extracted soil cores and by soil physical and chemical analyses. Data were analysed using ordination and interpreted with GIS software so that topographic features could be considered. The most frequently identified taxa were Hypochaeris radicata, Austrodanthonia spp. and Bothriochloa spp. (in late summer) and Vulpia spp., Bromus molliformis and Trifolium subterraneum (winter-annual species). Austrodanthonia spp. were commonly found on the drier ridges and more acid soils with lower phosphate levels. These were also the areas dominated in spring by Vulpia spp. and were generally lower in plant species richness overall. The most species-rich areas occurred downslope where soil fertility was higher and less moisture stress was presumably experienced. The measured environmental factors explained a substantial proportion of the variation in the vegetation dataset, which underlined the importance of considering landscape effects in the management of typical tablelands pastures.


2017 ◽  
Vol 10 (01) ◽  
pp. 26-32 ◽  
Author(s):  
Kyle C. Roerig ◽  
Corey V. Ransom

Feral cereal rye is an aggressive, persistent winter annual grass. Although feral rye has been documented as a weed in Utah cropland for many years, it has only recently been described as a weed of natural areas in Utah. After feral rye was observed on hillside locations where it had not previously been present, research was conducted to evaluate expansion rates in isolated patches and on a landscape scale. Individual patch measurements indicated expansion rates of 17%, 42%, 44%, and 112% in 2009. The landscape expansion rates were 1%, 4%, 8%, 21%, and 50% in the same year. The spread of feral rye appears to have occurred primarily on south- to west-facing slopes where the density and diversity of native species is limited. The expansion of feral rye into natural, undisturbed areas indicates that this species should be closely monitored. The relatively short seed longevity and current small infestations make it a good candidate for early detection/rapid response efforts.


2012 ◽  
Vol 63 (10) ◽  
pp. 1026 ◽  
Author(s):  
K. N. Tozer ◽  
E. Minneé ◽  
C. A. Cameron

Yellow bristle grass (Setaria pumila) and summer grass (Digitaria sanguinalis) are summer-active annual grass weeds which infest temperate dairy pastures. A study was undertaken over 2 years to compare hand-sown yellow bristle and summer grass establishment, survival, and seed production in pastures grazed by dairy cows and based on (i) tetraploid perennial ryegrass (Lolium perenne), (ii) tetraploid perennial ryegrass and white clover (Trifolium repens), and (iii) tall fescue (Festuca arundinacea) and white clover, to determine which pasture type offered the greatest resistance to these grass weeds. Ingress of grass weeds was similar in all three pasture types. Total dry matter production was similar for all pasture types for the first year and lower in tall fescue + clover than perennial ryegrass pasture in the second year. All pasture types had a similar distribution of microsite types (bare ground ± canopy, basal cover ± canopy) in both years. The annual grass weeds were most prevalent in bare ground + canopy microsites, which were also the most frequent of the four microsite types. In the first year, <5% of microsites were occupied within 2 months of sowing, whereas in the second year, microsite occupation remained >13% for all assessments. In the first year, panicle production of yellow bristle and summer grass was similar (averaging 4.1 panicles plant–1); in the second year, panicle production was greater for summer grass (0.80 v. 0.16 panicles plant–1, respectively). Where present, these annual grass weeds are likely to spread in dryland dairy pastures sown with either perennial ryegrass or tall fescue. Variability in their panicle production between years shows how their impact on pasture performance and consequent need for control measures will also vary from year to year.


2014 ◽  
Vol 7 (3) ◽  
pp. 387-397 ◽  
Author(s):  
Chengchou Han ◽  
Stephen L. Young

AbstractRoot architecture of prairie grasslands, which depends on plant phenology and edaphic conditions, strongly influences susceptibility to invasion by nonindigenous plant species. Field studies were conducted to compare in situ root growth patterns of warm-season (WS) and cool-season (CS) perennial grasses and musk thistle during a 2-yr period that included a drought in the second year. In 2 yr, CS grasses had the highest amount of roots (1,296 m roots m−2 [395 ft roots ft−2]) across shallow (0 to 28 cm [0 to 11 in.]), medium (28 to 56 cm), and deep (56 to 98 cm) depths with 65% occurring in the shallow depths. However, roots of WS grasses were always greater at deeper depths compared to roots of CS grasses. The amount of new roots in CS grasses was statistically different in 2011 (F2,43 = 33.3, P < 0.0001) at all depths for vegetative (April to May), inflorescence (June), and dormant (July to November) stages. In 2012, the amount of new roots in CS and WS grasses was statistically different (F2,60 = 81.7, P < 0.0001 and F2,37 = 8.0, P = 0.0013), respectively, for vegetative (April to May), inflorescence (May to June), and dormant (June to November) stages. For both years, the amount of new roots in the CS grasses showed an interaction between the three growth stages and three soil depths (F2,62 = 33.3, P < 0.0001 [2011]; F4,60 = 18.6, P < 0.0001 [2012]). From germination to senescence, the total amount of musk thistle roots was 298 m roots m−2, which was less than the CS (1,296 m roots m−2) and WS (655 m roots m−2) grasses. The largest proportion of new musk thistle roots (61%) (F2,42 = 40.4, P < 0.0001) occurred during the bolting stage (April to June) of the second year. These results show the difference in root distribution of two grass types and the niches that are created underground by extraneous conditions (e.g., drought) in WS grass stands that may contribute to the establishment of musk thistle, an invasive plant species in many North American regions.


2013 ◽  
Vol 46 (2) ◽  
pp. 27-37
Author(s):  
C. Ailincăi ◽  
G. Jităreanu ◽  
D. Bucur ◽  
Despina Ailincăi

Abstract Experiments conducted at Agricultural Research and Development Station of Podu-Iloaiei, Iaşi County, Romania, during 2002 - 2011, followed study runoff and soil erosion in different cultures, and establish critical season of soil erosion in this area. Establish critical season of soil erosion is necessary to satisfy the critical level of ground cover, which is required to maintain a low risk of soil erosion. Average annual soil loss by erosion, recorded in maize and sunflower were (mean on 10 years) of 6.753 and 7.385 t/ha/year, respectively. In sunflower and corn of the total soil loss recorded in the Moldavian Plateau, 19.7- 20.4% occurred in spring, 68.7 to 69.2% in summer and 6.1- 6.6% in the autumn. Differences of 4.5 to 4.9% of the total annual soil losses by erosion were recorded in winter, with snow melt. Season critic of soil erosion in the Moldavian Plateau, when recording the most aggressive rain event occurs in June and July. Mean soil loss due to erosion, recorded in June and July were 0.424 t/ha for winter rape, winter wheat 0.291 and 0.093 t/ha the perennial grasses in the second year of vegetation.


2009 ◽  
Vol 60 (11) ◽  
pp. 1088 ◽  
Author(s):  
K. N. Tozer ◽  
D. F. Chapman ◽  
R. D. Cousens ◽  
P. E. Quigley ◽  
P. M. Dowling ◽  
...  

A field experiment was established in a southern Australian temperate pasture to investigate the effects of identity and proximity of perennial grasses on the demography of the annual grasses Vulpia spp. (V. myuros, V. bromoides) and Hordeum leporinum (barley grass). Annual grasses were grown either alone or in mixtures, at different distances from rows of Dactylis glomerata (cocksfoot) and Phalaris aquatica (phalaris). Dactylis had a greater suppressive effect than Phalaris on Vulpia and Hordeum. Biomass, tiller production, and panicle production of annual grasses increased linearly with increasing distance from the perennial row. Tiller and panicle production were greater for Vulpia than Hordeum. The estimated rate of population growth (λ) for annual grasses was greater in Phalaris than in Dactylis and in Vulpia than in Hordeum, and increased with sowing distance from perennial grass rows. It was estimated that λ, when seeds were sown directly adjacent to a row of perennial grasses, was 1 and 0.4 for Vulpia and Hordeum, respectively, within Dactylis stands, and 7 and 3, respectively, within Phalaris stands. However, 15 cm from the row, λ reached 50 and 39 for Vulpia and Hordeum, respectively, within Phalaris stands, and 39 and 16, respectively, within Dactylis stands. In grazed, dryland pastures, perennial competition alone is therefore unlikely to prevent population growth of annual grasses, especially in systems heavily disturbed by grazing or drought. However, Dactylis showed more promise than Phalaris in limiting the abundance of these weeds.


2011 ◽  
Vol 33 (1) ◽  
pp. 67 ◽  
Author(s):  
Y. Alemseged ◽  
R. B. Hacker ◽  
W. J. Smith ◽  
G. J. Melville

Thickening of native shrubs is a major problem in many ‘semi-arid woodlands’ as significant increase in shrub density is often negatively correlated with herbaceous vegetation and leads to reduced pasture production and soil erosion. This project aimed to test the hypothesis that temporary cropping (up to three crops in 15 years) consistently increases the density of native perennial grasses following the removal of shrubs. A total of 30 paddocks that had been cropped during the last 20 years were randomly selected using a satellite-based database that documented annual clearing and cropping history from 1987 to 2003. Paddocks were classified into four types based on clearing and cropping history and grazing management – not cleared (shrubs), regrowth (re-invaded by shrubs), set stocked (cropped and grazed), light/rotationally grazed (cropped and grazed). The responses of vegetation and soil (chemical and physical) properties to clearing and cropping were evaluated. Results indicated that ground cover, native perennial grass cover and standing dry matter were highest under light/rotationally grazed conditions. The shrub state represents a stable state within the Cobar pediplain brought about due to land-use change in the form of overgrazing and/or the removal of fire from the system. An alternative stable state was achieved as a result of disturbance in the form of clearing, cropping and grazing management thereby directly altering the shrub population. The resilience of this state is largely dependent on the grazing management system used and on the prevention of shrub from re-establishing while failure to control shrubs could lead to the re-emergence of the Shrub State. We conclude that native grasslands do regenerate following cropping after removal of shrubs. The importance of grazing management for restoring perennial ground cover following removal of shrubs and temporary cropping has been clearly demonstrated by the study.


2011 ◽  
Vol 33 (1) ◽  
pp. 87 ◽  
Author(s):  
R. B. Hacker ◽  
I. D. Toole ◽  
G. J. Melville

The roles of nitrogen (N) and phosphorus (P) in controlling vegetation transitions in a degraded semi-arid grassland were investigated in a factorial experiment that combined two initial levels of perennial plant density (low and high), three levels of N (N+, N0 and N–) and two levels of P (P+ and P0). Increased levels of both N and P were achieved by fertiliser addition while sucrose was used to reduce the level of N. Vegetation dynamics were driven primarily by soil N rather than P. Addition of sucrose, which was inferred to result in the immobilisation of mineral N, reduced the growth of annual species and facilitated the establishment and growth of native perennial grasses. Addition of P generally had no significant effect on dry matter production, either in total or for species grouped as forbs, annual grasses and perennial grasses, or on recruitment and mortality of perennial grasses. However, at some times of observation addition of P increased ground cover and/or the basal circumference of some perennial grass species. Basal circumference for Enteropogon acicularis was also increased by addition of N. Soil biological activity, measured by decomposition of cotton strips, was increased by addition of N, which maintained vegetation in an annual-dominated condition, and was not affected by addition of P. Carbon addition has the potential to assist restoration of this grassland. However, the capacity of some native grass species to respond to increased fertility suggests that once restoration is achieved some increase in fertility may be beneficial for pastoral production.


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