Corey Ransom - Research

Corey's Research


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The overall objective of Dr. Corey Ransom's research program is to improve weed management approaches to improve agriculture economic viability and to protect natural areas in Utah and the Western U.S. This broad objective is accomplished by focusing on three thematic areas (see below for more detail):



Weed Biology and Ecology

This research focuses on understanding the fundamental attributes that make weeds successful, the ways in which weeds spread, and the impacts of weeds on agricultural and natural areas. Research in this more basic area of science is often important in the development of effective weed management systems and for large scale weed management. While this research area is extremely important, funding for work on specific weed species, especially those unique to Utah or the Intermountain West, is often difficult to secure. In this area, research has been done to understand goatsrue seed dormancy, germination, persistence, and seed bank densities as well as toxin levels in goatsrue in different plant parts and growth stages. Funding was provided from startup funds.

Another project evaluated salinity tolerance of foxtail barley (undesirable grass) and several desirable pasture grasses in order to identify species that could be as persistent as foxtail barley in saline soils. Funding for this project was provided by a New Faculty Research Grant.

A survey to determine what weeds are most problematic in Utah tart cherry orchards was conducted under a USDA-Specialty Crop Grant money provided by the Utah State Horticulture Association (USHA). This work was used as partial justification for additional orchard funding to be discussed in the second focus area.

A project evaluating the spread of feral rye on non-crop hillsides was partially funded with a WSSA undergraduate research grant. Work on weed management in onions provided the setting where Iris Yellow Spot Virus (IYSV), a virus infecting onions, was found infecting two weed species. In the case of one species, green foxtail, the resulting journal article is the first report of a topovirus being hosted in a grass species.

A portion of recently received funding from the US Forest Service will be used to monitor movement of several highly invasive weeds over time, allowing the determination of the risk they pose to the natural environments that they infest.


Effective and Integrated Weed Management

This research focuses on identifying the most effective means of controlling weeds and examines the integration of different management tools that are available. Within this program area, research focuses on (A) development and testing of herbicides for crop safety and weed control efficacy and (B) developing integrated methods for effective weed control.

(A) Projects focused on herbicide evaluation have included trials in various crops and in non-crop areas funded by chemical companies as well as testing of herbicide response and tolerance of native forb species funded by U.S. Forest Service. The Forest Service project in particular relates to restoration efforts within the Intermountain West.

Work on new herbicide options in onion production was funded by the Utah Onion Growers Association. Components of projects as described above also evaluated herbicides for control of foxtail barley and goatsrue, respectively.

(B) Work on integrated techniques includes two current  projects at Dinosaur National Monument. Another project involves working on integration of goat grazing and herbicides for Russian knapweed control and the evaluation of mowing, spring herbicide treatment, and fall herbicide treatment combinations for downy brome management. An additional trial with company funding is evaluating tillage, herbicide treatment, and reseeding for reclamation of Russian knapweed infested sites.

Collaborative work with colleagues in the Department of Natural Resources at USU and the USDA-ARS Forage and Range Research Laboratory have evaluated herbicide and niche differentiation effects on desirable grass seedling establishment in downy brome restoration sites. The largest integrated management research project that Cory is involved with is an interdisciplinary project addressing orchard floor management. Funding for this project came from multiple grant sources including a USU Extension grant, and Utah Department of Agriculture and Food, Specialty Crop Grants. These funds were used to generate initial research used to obtain a USDA-Organic Agriculture Research and Extension Initiative grant.


Landscape or Large Scale Weed Management

This research focuses on identifying where weeds exist on the landscape and how to approach weed management on a landscape (watershed, forest, refuge, community) scale. This work includes invasive species inventory work and research developing effective and efficient inventory methods, development of processes for coordinated efforts to manage weeds, determining the impact of weed management strategies on a large scale, and developing decision tools to help land managers make critical decisions about weed inventory approaches and priorities. Previously the majority of the funding was to conduct weed surveys for public agencies including the BLM, Forest Service, National Park Service, and the Fish and Wildlife service. By training students to carry out weed inventories and refining inventory techniques, USU has developed expertise in weed assessment methods and approaches. Building on that expertise, we have continued to do inventory work but have begun to focus more on processes.

Projects have included inventory work for the public agencies, but more recently have included funding for weed monitoring, which has more of an ecological focus as discussed in the first program area, allowed testing of mapping methods for accuracy and time effectiveness as well as the opportunity to develop a guide and tools to be used by agency staff to determine how to prioritize the areas to be inventoried and the weed species to look for based on ranked criteria. This holds great potential to increase weed detection efficiency with limited budgets.

A re-inventory of areas within Dinosaur National Park has provided an evaluation of the control strategies employed there over the past six years. A decline in the weed populations within treated areas suggests the management approach is working effectively.

Another aspect of this program area has been the evaluation of the concept of Weed Prevention Areas (WPA’s). This concept puts a greater value on prevention measures as opposed to control measures and is funded by the USDA-ARS Area-wide EBIPM Project. The research funding has helped to support the formation of a weed prevention area. A survey and on the ground inventory was conducted prior to WPA establishment and after two years will be utilized to evaluate impacts of this organization on public perception of weed management and actual weed distribution and frequency at the end to the project compared to areas where no WPA was established. A major outcome of this project so far is the publication of an extension bulletin “Establishing a Weed Prevention Area: A step-by-step user’s guide”.

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