Integrated Weed Management of non-native annual grass, Ventenata dubia, in Montana rangelands

View the project report

Commodities

• Agronomic: grass (misc. perennial), hay
• Additional Plants: native plants

Practices

• Animal Production: feed/forage, range improvement, rangeland/pasture management
• Crop Production: nutrient cycling, nutrient management
• Education and Training: extension, mentoring, on-farm/ranch research, other, workshop
• Natural Resources/Environment: biodiversity, habitat enhancement
• Pest Management: chemical control, competition, integrated pest management, weed ecology
• Production Systems: dryland farming

Montana producers are in a constant balance of managing non-native annual weeds and producing quality forage in high quantities. Ventenata is a non-native annual grass first identified in the United States in 1952 and identified in Montana in the 1990s. As a species with high drought tolerance and low forage quality, it is imperative we find integrated weed management strategies to control this species, while improving forage quality. Our goals are to improve our understanding of ventenata ecology, evaluate integrated weed management practices to control ventenata, increase desired forage and grassland sustainability. We intend to address these goals through two field studies: 1) ventenata and forage response to different growth conditions (current, warmer, warmer + drier) with and without herbicide treatment; and 2) ventenata and forage response to integrated management strategies with herbicides (Axiom, Rejuvra, Rejuvra + Plateau) and fertilizers (N, micronutrient, no fertilizer). Our approach is unique and will add to existing knowledge of how to manage this invasive species. We will share the outcomes of this research with producers, managers, and Montana State University students through several different outreach strategies. We will publish locally and in peer reviewed publications. The findings of this project will provide producers and managers with vital information for controlling ventenata while simultaneously increasing forage quantity and quality using integrated strategies under differing climatic conditions.  

The research goals of this project are to evaluate integrated weed management approaches to suppress ventenata and improve quality and quantity of forage by increasing desired grasses. To assess our goals we have three objectives, each with sub-objectives.  

The main objectives are: 

Objective 1) Quantify ventenata’s competitive ability with other vegetation under different  growth conditions (current, warmer, and warmer + drier conditions). These data will allow me to quantify:  

1a) the response of ventenata to herbicide (Rejuvra, no spray) under different growth conditions, 

1b) if forage and other vegetation are impacted by ventenata and herbicide  (Rejuvra, no spray) under different growth conditions, and 

1c) if ventenata cycles N more rapidly than cheatgrass and forage species under current conditions. 

Objective 2) Evaluate effectiveness of integrated management approaches with herbicides (Axiom, Rejuvra, Rejuvra + Plateau, no spray) and fertilizer (N, micronutrient, no-fertilizer) to control ventenata and improve abundance and quality of desired species. These data will allow me to quantify: 

2a) the response of ventenata under different treatment combinations, 

2b) if forage and native vegetation are impacted by the treatment combinations, and  

2c) if forage quality is impacted by the different treatments.  

The educational goals of this project are to further educate Montana producers and managers, the public, and students about the non-native grass ventenata and share outcomes of integrated weed management approaches to suppress ventenata and improve quality and quantity of forage. To assess our goals, we have three objectives.  

The main objectives are: 

Objective 1) Share our results on the ecology and management of ventenata with producers and managers. 

1a) Educate individuals on integrated management strategies effective on ventenata so that they may make informed management decisions for their own properties. 

1b) Educate individuals on the identification of ventenata and its ecology under different climates.  

Objective 2) Share our results about the quality and quantity of forage following integrated management strategies with producers and managers. 

2a) Educate individuals on the outcomes of forage quality tests on ventenata and desired species following management so that they make informed management decisions. 

2b) Educate individuals on the changes to forage quantity following management so they may make informed management decisions.  

Objective 3) Present research to students at Montana State University enrolled in introductory, intermediate, and advanced plant ecology related courses.