Progress 09/01/12 to 08/31/15
Outputs
Target Audience:The target audience of this project included 1) Small grain organic and conventional farmers, 2) ranchers, 3) Crop advisors, 4) County Extension Agents, 5) Undergraduate and graduate students, and 6) Regional, national, and international researchers and colleagues working in natural resource management. Efforts to reach this audience included 1) Formal classroom instruction, 2) Presentation at field days and extension meetings, 3) Workshops, 4) Printed and electronically distributed extension material, 5) Presentations at professional meetings, and 6) Peer-reviewed publications Changes/Problems:In August 2014, our P. semeniperda got contaminated with other fungi. To solve this problem, we collected more B. tectorum seeds and we are currently isolating P. semeniperda. This new colony was used to complete our studies. What opportunities for training and professional development has the project provided?Kirsta Ehlert, the PhD student of this project, presented the results of this research at the 2014 Crop and Weed Field Day and at several local, regional, and national meetings including the Weed Science Society of America Meeting in Vancouver, Canada; the Northwest Scientific Association Annual Meeting. Missoula, MT, and the Montana Weed Control Association Annual Conference. Great Falls, MT; among others. Ali Thornton, the undergraduate student of this project, presented her results at the Montana State University - Student Research Celebration. She has also received the Weed Science Society of America Undergraduate Award and will present her results at the society annual meeting. How have the results been disseminated to communities of interest?Throughout the duration of this project, we have given numerous presentations about our work with P. semeniperda and cheatgrass management within the state of Montana and at regional and national scientific conference. These presentations are listed below and were given to a range of audiences, including Extension audiences (land managers, agency personnel, stakeholders) and the scientific community. Extension Presentations (550.25 total contact hours) Mangold, J.25 September 2013. Cheatgrass update.45 people in attendance (22.5 contact hours).Glasgow, MT. Mangold, J.25 October 2013.Cheatgrass management.45 people in attendance (22.5 contact hours).Medicine Hat, Alberta, Canada. Mangold, J.4 October 2013. Cheatgrass research and Extension across Montana.10 people in attendance (3 contact hours). Bozeman, MT. Mangold, J.2 January 2014.Current and future challenges to managing cheatgrass.44 people in attendance (44 contact hours). Bozeman, MT. Mangold, J. and F. Menalled. 31 January 2013. Cheatgrass management in crop and non-crop areas. 115 people in attendance (115 contact hours). Great Falls, MT. Ehlert, K.A., Z. Miller, F. Menalled, A. Dyer, and J. Mangold. 19 November 2013. Cheatgrass biological control. Montana Weed Control Association - Biological Control Working Group. 20 people in attendance (0.25 contact hours). Bozeman, MT. Ehlert, K.A. 21 May 2014. Cheatgrass, Bromus tectorum. Building Bridges: Invasive Grass Workshop. 47 people in attendance (47 contact hours). Missoula, MT. Ehlert, K.A. 7 July 2014. Cheatgrass (Bromus tectorum) management. Montana State University's Crop and Weeds Field Day. 130 people in attendance (65 contact hours). Bozeman, MT. Ehlert, K.A. 1 October 2014. Cheatgrass: Management recommendations and new research. Noxious Weed Management Certification Workshop - Level 2. 16 people in attendance (12 contact hours.) Bozeman, MT. Mangold, J. 28 January 2015. Cheatgrass management in range, pasture, and forage.100 people in attendance (125 contact hours). Helena, MT. Mangold, J. 19 March 2015.Cheatgrass management in range, pasture, and forage.75 people in attendance (75 contact hours).Big Timber, MT. Menalled, F. April 2015. Cheatgrass Management. Understanding this invasive grass and ways that may help in minimizing its impacts. 25 people in attendance (19 contact hours). Ennis, MT. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Susceptibility of non-target species to P. semeniperda Cheatgrass, crop, forage, and rangeland species were used to assess how germination speed related to impaction by P. semeniperda. This experiment consisted of a factorial combination of two P. semeniperda treatments [inoculated (5,000 conidia ml-1, 5 ml per 25 seeds) and non-inoculated] and 16 grass species: cheatgrass and 15 species from 5 crop (winter wheat, Triticum aestivum; barley, Hordeum vulgare; rye, Secale cereal; oat, Avena sativa; and triticale, X Triticosecale), forage (Crested wheatgrass, Agropyron cristatum; tall fescue, Festuca arundinacea; smooth brome, B. inermis; Russian wildrye, Elymus junceus; and Orchardgrass, Dactylum glomerata), and rangeland (prairie junegrass, Koeleria cristata; Idaho fescue, Festuca idahoensis; bluebunch wheatgrass, Pseudoroegneria spicatum; blue grama, Bouteloua gracilis; little bluestem, Schizachyrium scoparium) settings. Treatments were replicated 8 times in two greenhouses. Pyrenophora semeniperda reduced cheatgrass density by approximately 40% relative to the control (P < 0.0001. Barley and rye were negatively affected by P. semeniperda, with rye density reduced approximately five times more (34%) than barley (8%). Three (crested wheatgrass, smooth brome, and Russian wildrye) of the five forage species were negatively affected by P. semeniperda. On average, P. semeniperda reduced the density of these species by 30%. Density of four of the five range species was reduced by P. semeniperda, with the reduction in density ranging from 20 to 80%. Effectiveness of P. semeniperda on B. tectorum control The study was conducted at a site located 8.2 km east of Bozeman, MT. Cheatgrass seeds were broadcast seeded in September 2012 at a rate of 150 seeds m-1 to 2 m x 1 m plots. A combination of three cheatgrass growth stages (early flowering, peak flower, and after seed maturation) and two P. semeniperda inoculation timings (morning, and night) was assigned to plots. Treatments were replicated eight times in a randomized complete block design. Pyrenophora semeniperda was applied at the rate of 250 ml m-2 (5,000 conidia ml-1). Cheatgrass density was sampled on October 8, 2013 and re-sampled on June 16, 2014 using two 100 cm2 rings randomly placed within the center of each plot. Rings were permanently placed to help assess overwinter mortality. Peak biomass of cheatgrass, perennial broadleaf weeds, and annual broadleaf weeds was sampled on July 2, 2014 and July 8, 2015 using one 20 cm x 50 cm frame randomly placed within each plot. Biomass was clipped, dried and weighed. Soil samples were collected after seed shatter to assess seedbank disease status and viability. Analysis of variance was used to evaluate P. semeniperda effects on B. tectorum density and biomass. Model predictors were B. tectorum growth stage, P. semeniperda inoculation timing, and year as well as their interactions. Results revealed that the timing of application had no effect on B. tectorum density (p = 0.4835). However, we did find differences in B. tectorum density among years (p < 0.001). The lack of P. semeniperda efficacy in this study raises some questions. Among them, were environmental conditions unfavorable for P. semeniperda establishment? Are there other microbes present in the soil that compete against P. semeniperda, rendering it ineffective? These are future research questions that need to be addressed to better understand P. semeniperda efficacy in the field, as our greenhouse results indicate that it is effective in reducing B. tectorum density. Integrated management of cheatgrass in crops This experimentofthe integration of cultural, chemical and biological practices to improve cheatgrass management in a crop systems. The site was located at 8.8 km west of Bozeman, MT. Cheatgrass was broadcast seeded fall 2012 at the rate of 150 seeds m-1 to 2 m x 2 m plots. A combination of three nitrogen treatments (fall, spring, and none), three herbicide treatments (sulfosulfuron; fall, spring, and non-sprayed), and two P. semeniperda treatments (inoculated, and non-inoculated) was assigned to plots. Treatments were replicated four times in a randomized complete block design. All plots were drill seeded on September 19, 2013 with difenoconazole-treated winter wheat (var: Clearfield, 68 kg ha-1) with 25.4 cm row spacing. Nitrogen was broadcasted at the rate of 168 kg ha-1 on October 18, 2013 and May 12, 2014. Sulfosulfuron was applied at 14.0 g ai ha-1 using a CO2 backpack sprayer delivering 210 L ha-1 water at 294 kPa on November 2, 2013 and May 13, 2014 for the fall and spring applications, respectively. Pyrenophora semeniperda was applied on October 1, 2013 at the rate of 250 ml m-2 (5,000 conidia ml-1. Cheatgrass density was sampled for two years on November 19 2013, May 22, 2014, and May 20 2015, with winter wheat density also sampled on the first two date. Cheatgrass peak biomass was sampled on 2 June 26, 2014 and June 22-23, 2015, immediately prior to seed shatter. The center five rows of winter wheat were harvested at peak biomass on August 5, 2014. Biomass was clipped, dried (50°C for 72 hours) and weighed. Soil samples were collected to determine seed disease status and viability. Nitrogen, herbicide treatment, and P. semeniperda inoculation were non-significant (nitrogen, p = 0.5241; herbicide, p = 0.3631; P. semeniperda, p = 0.2311) in determining B. tectorum density. The interactions of herbicide and year (p = 0.0016) and P. semeniperda and year (p = 0.0340) suggest a lack of residual activity of sulfosulfuron. These observations, reveal that there is a part of the P. semeniperda-B. tectorum pathosystem that does not translate from greenhouse to field setting. Future research should investigate the mechanisms responsible for these differences. Integrated management of cheatgrass in a rangelands The site was located 10.5 km northwest of Amsterdam, MT. In fall 2013 a factorial combination of two P. semeniperda treatments (inoculated, and non-inoculated), two herbicide treatments (imazapic and non-sprayed), two perennial grass seeding rates [recommend rate (1X), and twice the recommended rate (2X)], and two seed-fungicide applications (difenoconazole and non-treated) was randomly assigned to plots and replicated four times in a randomized complete-block design. Pyrenophora semeniperda was applied on 23 September 2013 at the rate of 250 ml m-2 (5,000 conidia ml-1). Imazapic was applied at 120 g ai ha-1 was mixed with water plus a non-ionic surfactant with a CO2 backpack sprayer delivering 210 L ha-1 water at 294 kPa on 3 November 2013. Bluebunch wheatgrass (Pseudoroegneria spicata) and prairie Junegrass (Koeleria macrantha) were hand seeded on 18 April 2014 at 13.3 or 26.6 kg ha-1 (1X or 2X) and 2.2 or 4.4 kg ha-1 (1X or 2X), respectively. After completing all applications, cheatgrass and perennial grass density were sampled 29 July 2014 and 25-26, 29-30 June 2015 using a 20 cm x 50 cm frame. Cheatgrass density was counted with a 20 cm x 12.5 cm frame. Broadleaf annual and perennial weeds were also counted. Soil samples were collected on 28 August 2014 (after seed shatter) to determine seed disease status and viability. Cheatgrass, perennial grass, and broadleaf annual and perennial weed biomass were sampled on 25-26, 29-30 June 2015. Biomass was clipped from each of the two Daubenmire frames, dried (50°C for 72 hours), and weighed. Soil samples that were collected will be processed. Data analysis will be conducted using analysis of variance to evaluate treatment effects on Bromus tectorum, perennial grass, and broadleaf perennial density and biomass. Model predictors will be P. semeniperda inoculation, herbicide treatment, perennial grass seeding rate, fungicide treatment, and year as well as their interactions. Logistic regression will determine treatment effects on seed disease status and viability, using the same model predictors as previously stated.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A., J.M. Mangold, and R. Engel. 2014. Integrating the herbicide imazapic and the fungal pathogen Pyrenophora semeniperda to control Bromus tectorum. Weed Research 54:418-424.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Ehlert, K.A. J. Mangold, F. Menalled, Z. Miller. 10 August 2015. Using a fungal pathogen to control a non-native invasive plant, despite spillover effects. Ecological Society of America Annual Meeting. Baltimore, MD
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Thornton, A., K. Ehlert, F. Menalled, and J. Mangold. 9 April 2015. Impact of nitrogen availability and time of inoculation on Pyrenophora semeniperda effectiveness as a biocontrol of Bromus tectorum. Montana State University Student Research Celebration. Bozeman, MT. (Poster)
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A., J. Mangold, Z. Miller, F. Menalled, R. Engel, and A. Dyer. 21 April 2014. Non-target effects and integration of Pyrenophora semeniperda, a fungal pathogen for cheatgrass control. Montana State University Land Resources and Environmental Sciences Student Research Colloquium. Bozeman, MT. (Poster)
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A. 24 March 2014. Optimizing efficacy of cheatgrass biocontrol in crops and rangelands: Integration and implementation. Montana State University Land Resources and Environmental Sciences Departmental Seminar. Bozeman, MT.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A., F. Menalled, J. Mangold, Z. Miller, and A. Dyer. 10 March 2014. The potential for downy brome control with a fungal pathogen. Western Society of Weed Science Annual Meeting. Colorado Springs, CO.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A., Z. Miller, J. Mangold, and F. Menalled. 5 Feburary 2014. Efficacy of downy brome (Bromus tectorum) biocontrol on target and non-target species. Weed Science Society of America Annual Meeting. Vancouver, British Columbia, Canada.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A., R. Engel, J. Mangold, Z. Miller, F. Menalled, and H. Parkinson. 15 January 2014. The black fingers of death: A nightmare for cheatgrass populations? Montana Weed Control Association Annual Conference. Great Falls, MT.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Ehlert, K.A., Z. Miller, J. Mangold, F. Menalled, and A. Dyer. 7 November 2013. Cheatgrass (Bromus tectorum) biocontrol: Effects on target and non-target species. Montana Chapter Society of Conservation Biology Research Symposium. Bozeman, MT.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A., Z. Miller, J. Mangold, F. Menalled, and A. Dyer. 27 March 2014. Influence of the fungal pathogen Pyrenophora semeniperda on downy brome (Bromus tectorum) and associated grassy species. Northwest Scientific Association Annual Meeting. Missoula, MT.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Mangold, J., K. Ehlert, and R. Engel. 13 March 2013. Integrating imazapic and a fungal pathogen to control downy brome (Bromus tectorum). Western Society of Weed Science Annual Meeting. San Diego, CA.
|
Progress 09/01/13 to 08/31/14
Outputs
Target Audience: The target audience of this project included 1) Small grain organic and conventional farmers, 2) ranchers, 3) Crop advisors, 4) County Extension Agents, 5) Undergraduate and graduate students, and 6) Regional, national, and international researchers and colleagues working in natural resource management. Efforts to reach this audience included 1) Formal classroom instruction, 2) Presentation at field days and extension meetings, 3) Workshops, 4) Printed and electronically distributed extension material, 5) Presentations at professional meetings, and 6) Peer-reviewed publications. Changes/Problems: In August 2014, our P. semeniperda got contaminated with other fungi. To solve this problem, we collected more B. tectorum seeds and we are currently isolating P. semeniperda. We do not expect that this will create major problem for our future greenhouse and field activities. What opportunities for training and professional development has the project provided? Kirsta Ehlert, the PhD student of this project, presented the results of this research at the 2014 Crop and Weed Field Day and at several local, regional, and national meetings including the Weed Science Society of America Meeting in Vancouver, Canada; the Northwest Scientific Association Annual Meeting. Missoula, MT, and the Montana Weed Control Association Annual Conference. Great Falls, MT; among others. How have the results been disseminated to communities of interest? During 2014, Drs. Jane Mangold and Fabian Menalled presented more than 12 Extension talks across Montana highlighting integrated B. tectorum management options in crop and non-crop areas. Overall there were approximately 500 people in attendance. What do you plan to do during the next reporting period to accomplish the goals? We will continue to culture P. semeniperda in the lab to produce more inoculum to continued our greenhouse and field work.
Impacts
What was accomplished under these goals?
We isolated Pyrenophora semeniperda stromata, the “black fingers of death,” from B. tectorum seeds. Pyrenophora semeniperda was cultivated on water agar plates to obtain conidia, which are the spores responsible for infecting the B. tectorum seedbank. After transferring a single conidium to a modified alphacel medium (MAM) plate, P. semeniperda growed in concentric rings. These P. semeniperda cultures were harvested and the resulting in a conidia solution was used for our greenhouse and field work. Greenhouse Work We completed the first two trials of a Study to evaluate the impact of P. semeniperda on target and non-target grass species, for a total of 15 species (Winter wheat, T. aestivum; crested wheatgrass, A. cristatum; prairie junegrass, K. cristata; barley, H. vulgare; tall fescue, F. arundinacea; Idaho fescue, F. idahoensis; rye, S. cereal; smooth brome, B. inermis; bluebunch wheatgrass, A. spicatum; wild oat, A. sativa; russian wildrye, E. junceus; blue gramma, B. gracilis; triticale, X Triticosecale; orchardgrass, D. glomerata, and little bluestem, S. scoparium) tested in addition to B. tectorum. Treatments included: a) inoculated with P. semeniperda and b) non-inoculated (control). All species were assessed for germinability prior to seeding. Twenty plants per pot was determined to be a desirable number of plants to collect data on, while minimizing effects of competition from space and nutrient limitations. Seeds were inoculated by placing them in small Petri dishes filled with P. semeniperda inoculum (5 mL inoculum per 25 seeds) on a shaker table for 14 hours at 50 rpm to allow for the absorption of P. semeniperda inoculum. The greenhouse potting soil we used consisted of equal parts by volume of loam mineral soil, washed concrete sand, peat moss, and vermiculite. After being planted to a depth of 0.50 cm, seedlings were allowed to grow for four weeks in greenhouse conditions (21.1°C day and 12.8°C night). Plant density was recorded weekly, and aboveground biomass was clipped at harvest, dried in a drying oven at 50°C for 72 hours, and weighed. Our results show that P. semeniperda impacted species’ emergence (P < 0.0001) and biomass (P < 0.0001). In general, P. semeniperda resulted in lower emergence for all species, compared to the untreated control. This effect appeared to be more pronounced for the rangeland species. For example, Prairie junegrass emergence decreased from 45% to 18%. In addition, P. semeniperda reduced emergence of all crop species by only 7-23%, with the exception of winter wheat where no emergence reduction was observed. Moreover, plant biomass of the crop species was higher than it was for the forage and rangeland species. The effect of P. semeniperda is likely due to biomass differences between the control and P. semeniperda treatment for winter wheat, triticale, smooth brome, and Russian wildrye. Plant biomass of all the other species was similar between treatments. For example, the control and P. semeniperda treatments resulted in crested wheatgrass biomass that was 14.5 and 15.3 kg plant-1, respectively. These results suggest that P. semeniperda could decrease target and non-target species’ emergence compared. Species that experience reduced emergence compensate by growing just as large as species that have more plants present, and therefore must compete for space and nutrients. Field Work We are completed the first field season of three different experiments that explore 1) enhancing P. semeniperda effectiveness on B. tectorum control, 2) integrating management of B. tectorum in crop settings, and 3) integrating management of B. tectorum in rangeland. Experiment I A randomized complete block design with eight blocks was established at the Montana State University (MSU) Fort Ellis Experimental Farm located 10 km east of Bozeman, MT, to investigate the impact of different application methods on the effectiveness of P. semeniperda on B. tectorum control. The field was seeded with B. tectorum to mimic an extensive infestation. A total of 150 seeds m-2 were seeded by hand-broadcasting and then gently raking a thin (< 1 cm) layer of soil over the seeds. In June 2013, the entire site was divided to accommodate a factorial of three different plant stages (early flowering, peak flowering, after seed maturation) and two different inoculation timings (morning, evening), as well as an untreated control, to 1 m x 2 m plots. Inoculation consisted of applying P. semeniperda inoculum with a CO2-backpack sprayer at the rate of 250 ml m-2 once B. tectorum had reached the appropriate flowering stage. Bromus tectorum emergence and growth was evaluated during the 2014 growing season. Data are currently being analyzed. Experiment II. This study follows a randomized complete block design with four blocks at the MSU Post Agronomy Farm to evaluate the integrated management of downy brome in a crop setting. The experiment consists of a factorial of two nitrogen (N) application timings (fall, spring), three herbicide treatments (none, fall, spring), and two P. semeniperda treatments (untreated, inoculated) to 2 x 2 m2 plots. There is a 1.5 m buffer between plots to limit the movement of P. semeniperda and drift form our herbicide treatments. In fall 2013, all plots were seeded with a non-competitive winter wheat variety, at the rate of 1 bushel A-1. Nitrogen application using urea pills occurred in early October 2013 and April 2014. Sulfosulfuron (Maverick®) was applied at the rate of 22.9 g a.i. ha-1 either in late September 2013 when B. tectorum is at the 2-3 leaf stage, and in May 2014. Lastly, P. semeniperda will be applied prior to B. tectorum emergence as outlined for Experiment I. Experiment III. This study evaluates integrated management approach in rangeland settings. We established a randomized complete block design with four blocks at a B. tectorum-infested site outside of Amsterdam, MT. We used a factorial of three herbicide treatments (none, pre-emergent imazapic, late post-emergent), two P. semeniperda treatments (untreated, inoculated), two fungicide treatments (untreated, treated), and two perennial grass seeding rates (1X, 2X). Imazapic (Plateau®) will be applied at the rate of 120 g a.i. ha-1 and applications will occur when B. tectorum is at the 1-2 and 3-4 leaf growth stage for the early and late post-emergent applications, respectively. Pyrenophora semeniperda application will occur as stated above for Experiment I.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Ehlert, K. A.; Mangold, J. M.; Engel, R. E. 2014. Integrating the herbicide imazapic and the fungal pathogen Pyrenophora semeniperda to control Bromus tectorum. WEED RESEARCH 54:418-424
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A., J. Mangold, Z. Miller, F. Menalled, R. Engel, and A. Dyer. 2014. Non-target effects and integration of Pyrenophora semeniperda, a fungal pathogen for cheatgrass control. Montana State University Land Resources and Environmental Sciences Student Research Colloquium. Bozeman, MT. 21 April, 2014.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A., Z. Miller, J. Mangold, F. Menalled, and A. Dyer. 2014. Influence of the fungal pathogen Pyrenophora semeniperda on downy brome (Bromus tectorum) and associated grassy species. Northwest Scientific Association Annual Meeting. Missoula, MT. 27 March, 2014.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A., F. Menalled, J. Mangold, Z. Miller, and A. Dyer. 2104. The potential for downy brome control with a fungal pathogen. Western Society of Weed Science Annual Meeting. Colorado Springs, CO. 10 March 2014.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A., Z. Miller, J. Mangold, and F. Menalled. 2014. Efficacy of downy brome (Bromus tectorum) biocontrol on target and non-target species. Joint Canadian Weed Science Society - Weed Science Society of America Annual Meeting. Vancouver, British Columbia, Canada. 5 February, 2014.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Ehlert, K.A., R. Engel, J. Mangold, Z. Miller, F. Menalled, and H. Parkinson. 2014. The black fingers of death: A nightmare for cheatgrass populations? Montana Weed Control Association Annual Conference. Great Falls, MT. 15 January, 2014.
|
Progress 09/01/12 to 08/31/13
Outputs
Target Audience: Researchers, Extension Agents, Farm and Commodity Organizations, Farmers Ranchers, Natural Resource Management Specialists Government Agencies, etc. Changes/Problems: No major problem occurred. This project is proceeding on schedule and we anticipate successful execution of the three experiments. What opportunities for training and professional development has the project provided? In March 2013, Dr. Jane Mangold attended the Western Society of Weed Science conference in San Diego, CA. She presented results from the P. semeniperda and imazapic study that our graduate student, Krista Ehlert, conducted during her Master’s program. Kirsta Ehlert, the PhD student of this project, will present the results of this research at the 2014 Weed Science Society of America Meeting in Vancouver , Canada How have the results been disseminated to communities of interest? In January 2013, Drs. Jane Mangold and Fabian Menalled presented an Extension talk in Great Falls, MT on B. tectorum management in crop and non-crop areas. There were 115 people in attendance (115 contact hours). Dr. Z. Miller gave 6 presentations to a total of 130 attendants on cheatgrass biology, ecology, and management. What do you plan to do during the next reporting period to accomplish the goals? Lab Work We will continue to culture P. semeniperda in the lab to produce more inoculum to continued our greenhouse and field work. Greenhouse Work A second trial of our greenhouse experiment will be conducted winter 2013, using the same protocol as described above. In addition, we will conduct an additional experiment that will incorporate fungicide to investigate its influence in reducing the effects of P. semeniperda on species we found to be susceptible. Field Work Experiment I – Methods that enhance the effectiveness of P. semeniperda on downy brome control. In October/November 2013, we will measure: 1) B. tectorum emergence, 2) seed disease status, and 3) seed viability. Bromus tectorum emergence will be measured by randomly placing two 35.6 cm diameter metal rings in each plot, and counting the number of tillers per ring. These rings will be permanently placed using metal stakes. Seed disease status and viability will be evaluated with seeds collected from six representative B. tectorum plants per plot. A sub-sample of 100 seeds from each plot will be placed on blotter paper to determine germinability and disease status, with infected seeds displaying P. semeniperda stromata. Seeds will be scored as germinated/uninfected, germinated/infected, non-germinated/uninfected, and non-germinated/infected. As P. semeniperda is an indigenous fungal pathogen, it is likely that the untreated control will have some P. semeniperda present, which will serve as a baseline for the other treatments. Experiment II – Integrated management of B. tectorum brome in crop settings. In late October 2013 and early June 2014, we will measure 1) B. tectorum and winter wheat emergence, and 2) B. tectorum seed disease status and viability. Emergence will be measured by randomly placing two 10 x 10 cm frames within each plot, taking care to place the frames within the center of the plot to account for edge effects. Seed disease status and viability will be evaluated with the methods discussed for Experiment I. Further, B. tectorum height and seed production, and winter wheat height, yield, protein content, and test weights will be measured at the time of harvest in spring 2014. Experiment III – Integrated management of B. tectorum in rangeland settings. In late May and early September 2014, we will measure B. tectorum and perennial grass height and emergence using the method outlined for Experiment II. Seed disease status and viability will be measured using the method outlined for Experiment I. Overall, we feel that this project is proceeding on schedule and anticipate successful execution of the three experiments.
Impacts
What was accomplished under these goals?
Pyrenophora semeniperda stromata, the “black fingers of death,” were plucked from B. tectorum seeds to begin culturing P. semeniperda on water agar plates. After approximately 24 hours, the stromata produce conidia, which are the spores responsible for infecting the B. tectorum seedbank. After transferring a single conidium to a modified alphacel medium (MAM) plate, P. semeniperda growed in concentric rings. These P. semeniperda cultures were harvested by rinsing the MAM plates with water to remove the conidia from the agar surface, resulting in a conidia solution that was used for our greenhouse and field work. From the beginning of this project, we have so far successfully made 86 L of inoculum, which is enough to cover 344 m2. Greenhouse Work We have successfully completed the first trial of a greenhouse experiment in which we investigated the impact of P. semeniperda on target and non-target grass species, for a total of 15 species tested in addition to B. tectorum (Table 1). Treatments were: a) inoculated with P. semeniperda and b) non-inoculated (control). All species were assessed for germinability prior to seeding. Based on the size of the pots (2.2 L, 15 cm dia.), 20 plants per pot was determined to be a desirable number of plants to collect data on, while minimizing effects of competition from space and nutrient limitations. Therefore, the number of seeds planted for each species was relative to its germination rate. Each species was inoculated by placing seeds in small Petri dishes filled with P. semeniperda inoculum (5 mL inoculum per 25 seeds) on a shaker table for 14 hours at 50 rpm to allow for the absorption of P. semeniperda inoculum. The greenhouse potting soil we used consisted of equal parts by volume of loam mineral soil, washed concrete sand, peat moss, and vermiculite. After being planted to a depth of 0.50 cm, seedlings were allowed to grow for four weeks in greenhouse conditions (21.1°C day and 12.8°C night). Plant density was recorded weekly, and aboveground biomass was clipped at harvest, dried in a drying oven at 50°C for 72 hours, and weighed. Table 1. Crop, forage/pasture, and rangeland species tested for Pyrenophora semeniperda susceptibility. Bromus tectorum was also included in this study. Crop Species Forage/Pasture Species Rangeland Species Winter wheat, T. aestivum Crested wheatgrass, A. cristatum Prairie junegrass, K. cristata Barley, H. vulgare Tall fescue, F. arundinacea Idaho fescue, F. idahoensis Rye, S. cereal Smooth brome, B. inermis Bluebunch wheatgrass, A. spicatum Oat, A. sativa Russian wildrye, E. junceus Blue gramma, B. gracilis Triticale, X Triticosecale Orchardgrass, D. glomerata Little bluestem, S. scoparium Our results show that P. semeniperda impacted species’ emergence (P < 0.0001) and biomass (P < 0.0001). In general, P. semeniperda resulted in lower emergence for all species, compared to the untreated control. This effect appeared to be more pronounced for the rangeland species. For example, Prairie junegrass emergence decreased from 45% to 18%. In addition, P. semeniperda reduced emergence of all crop species by only 7-23%, with the exception of winter wheat where no emergence reduction was observed. Moreover, plant biomass of the crop species was higher than it was for the forage and rangeland species. The effect of P. semeniperda is likely due to biomass differences between the control and P. semeniperda treatment for winter wheat, triticale, smooth brome, and Russian wildrye. Plant biomass of all the other species was similar between treatments. For example, the control and P. semeniperda treatments resulted in crested wheatgrass biomass that was 14.5 and 15.3 kg plant-1, respectively. These results suggest that P. semeniperda could decrease target and non-target species’ emergence compared. Species that experience reduced emergence compensate by growing just as large as species that have more plants present, and therefore must compete for space and nutrients. Field Work We are conducting three different field experiments that explore 1) enhancing P. semeniperda effectiveness on B. tectorum control, 2) integrating management of B. tectorum in crop settings, and 3) integrating management of B. tectorum in rangeland. Experiment I – Methods that enhance the effectiveness of P. semeniperda on B. tectorum control. A randomized complete block (RBC) design with eight blocks was established at the Montana State University (MSU) Fort Ellis Experimental Farm located 10 km east of Bozeman, MT, to investigate the impact of different application methods on the effectiveness of P. semeniperda on B. tectorum control. The field was seeded with B. tectorum in late September 2012 to mimic an extensive infestation. A total of 150 seeds m-2 were seeded by hand-broadcasting and then gently raking a thin (< 1 cm) layer of soil over the seeds. In June 2013, the entire site was divided to accommodate a factorial of three different plant stages (early flowering, peak flowering, after seed maturation) and two different inoculation timings (morning, evening), as well as an untreated control, to 1 m x 2 m plots. Inoculation consisted of applying P. semeniperda inoculum with a CO2-backpack sprayer at the rate of 250 ml m-2 once B. tectorum had reached the appropriate flowering stage (Table 2). Table 2. Bromus tectorum flowering stage and corresponding date of application. Bromus tectorum flowering stage Date of application Early flowering June 15, 2013 Late flowering June 20, 2013 After seed maturation July 19, 2013 Experiment II – Integrated management of B. tectorum in crop settings. We established a randomized complete block design with four blocks at the MSU Post Agronomy Farm, located 9 km west of Bozeman, MT, to evaluate the integrated management of downy brome in a crop setting. The experiment consists of a factorial of two nitrogen (N) application timings (fall, spring), three herbicide treatments (none, fall, spring), and two P. semeniperda treatments (untreated, inoculated) to 2 x 2 m2 plots. There is a 1.5 m buffer between plots to limit the movement of P. semeniperda and drift form our herbicide treatments. All plots will be seeded with a non-competitive winter wheat variety, at the rate of 1 bushel A-1. Nitrogen application using urea pills will occur in early October 2013 and April 2014. Sulfosulfuron (Maverick®) will be applied at the rate of 22.9 g a.i. ha-1 either in late September 2013 when B. tectorum is at the 2-3 leaf stage, and in May 2014. Lastly, P. semeniperda will be applied prior to B. tectorum emergence as outlined for Experiment I. Experiment III – Integrated management of B. tectorum in rangeland settings. In addition to investigating B. tectorum management in crop settings, we are also interested in developing an integrated management approach in rangeland settings. Thus, we established a randomized complete block design with four blocks at a B. tectorum-infested site outside of Amsterdam, MT. We will use a factorial of three herbicide treatments (none, pre-emergent imazapic, late post-emergent), two P. semeniperda treatments (untreated, inoculated), two fungicide treatments (untreated, treated), and two perennial grass seeding rates (1X, 2X). Imazapic (Plateau®) will be applied at the rate of 120 g a.i. ha-1 and applications will occur when B. tectorum is at the 1-2 and 3-4 leaf growth stage for the early and late post-emergent applications, respectively. Pyrenophora semeniperda application will occur as stated above for Experiment I. A fungicide seed treatment will be applied to a perennial grass mix that will be seeded early October 2014 at 13.5 kg PLS ha-1 (pure live seed, % purity x % germination) (1X) and 27.0 PLS kg ha-1 (2X)
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