Corn growth and development & management information for replant decisions

1 online resource (PDF, 12 pages)This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu

Soybean growth and development & management information for replant decisions

1 online resource (PDF, 11 pages)This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu

Use of an Integrated Pest Management Assessment Administered Through TurningPoint as an Educational, Needs Assessment, and Evaluation Tool

University of Minnesota educators use an integrated pest management (IPM) survey conducted during private pesticide applicator training as an educational, needs assessment, and evaluation tool. By incorporating the IPM Assessment, as the survey is called, into a widely attended program and using TurningPoint audience response devices, Extension educators can gather information from a significant number of farmers in a timely and efficient manner. Interspersing TurningPoint questions throughout presentations also increases audience engagement and overall quality of the training. For example, weed management programming efforts around herbicide-resistance management have been significantly influenced and enhanced by results of the IPM Assessment

Managing Wicked Herbicide-Resistance: Lessons from the Field

Herbicide resistance is ‘wicked’ in nature; therefore, results of the many educational efforts to encourage diversification of weed control practices in the United States have been mixed. It is clear that we do not sufficiently understand the totality of the grassroots obstacles, concerns, challenges, and specific solutions needed for varied crop production systems. Weed management issues and solutions vary with such variables as management styles, regions, cropping systems, and available or affordable technologies. Therefore, to help the weed science community better understand the needs and ideas of those directly dealing with herbicide resistance, seven half-day regional listening sessions were held across the United States between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide resistance management. The major goals of the sessions were to gain an understanding of stakeholders and their goals and concerns related to herbicide resistance management, to become familiar with regional differences, and to identify decision maker needs to address herbicide resistance. The messages shared by listening-session participants could be summarized by six themes: we need new herbicides; there is no need for more regulation; there is a need for more education, especially for others who were not present; diversity is hard; the agricultural economy makes it difficult to make changes; and we are aware of herbicide resistance but are managing it. The authors concluded that more work is needed to bring a community-wide, interdisciplinary approach to understanding the complexity of managing weeds within the context of the whole farm operation and for communicating the need to address herbicide resistance

Managing Herbicide Resistance: Listening to the Perspectives of Practitioners. Procedures for Conducting Listening Sessions and an Evaluation of the Process

Seven half-day regional listening sessions were held between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide-resistance management. The objective of the listening sessions was to connect with stakeholders and hear their challenges and recommendations for addressing herbicide resistance. The coordinating team hired Strategic Conservation Solutions, LLC, to facilitate all the sessions. They and the coordinating team used in-person meetings, teleconferences, and email to communicate and coordinate the activities leading up to each regional listening session. The agenda was the same across all sessions and included small-group discussions followed by reporting to the full group for discussion. The planning process was the same across all the sessions, although the selection of venue, time of day, and stakeholder participants differed to accommodate the differences among regions. The listening-session format required a great deal of work and flexibility on the part of the coordinating team and regional coordinators. Overall, the participant evaluations from the sessions were positive, with participants expressing appreciation that they were asked for their thoughts on the subject of herbicide resistance. This paper details the methods and processes used to conduct these regional listening sessions and provides an assessment of the strengths and limitations of those processes

Managing Wicked Herbicide-Resistance: Lessons from the Field

Herbicide resistance is ‘wicked’ in nature; therefore, results of the many educational efforts to encourage diversification of weed control practices in the United States have been mixed. It is clear that we do not sufficiently understand the totality of the grassroots obstacles, concerns, challenges, and specific solutions needed for varied crop production systems. Weed management issues and solutions vary with such variables as management styles, regions, cropping systems, and available or affordable technologies. Therefore, to help the weed science community better understand the needs and ideas of those directly dealing with herbicide resistance, seven half-day regional listening sessions were held across the United States between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide resistance management. The major goals of the sessions were to gain an understanding of stakeholders and their goals and concerns related to herbicide resistance management, to become familiar with regional differences, and to identify decision maker needs to address herbicide resistance. The messages shared by listening-session participants could be summarized by six themes: we need new herbicides; there is no need for more regulation; there is a need for more education, especially for others who were not present; diversity is hard; the agricultural economy makes it difficult to make changes; and we are aware of herbicide resistance but are managing it. The authors concluded that more work is needed to bring a community-wide, interdisciplinary approach to understanding the complexity of managing weeds within the context of the whole farm operation and for communicating the need to address herbicide resistance

Velvetleaf (\u3ci\u3eAbutilon theophrasti\u3c/i\u3e) Recruitment, Survival,Seed Production, and Interference in Soybean (\u3ci\u3eGlycine max\u3c/i\u3e)

Field studies were conducted at Rosemount, MN, in 1992 and 1993 to quantify the demographic processes regulating the population dynamics of velvetleaf in soybean as part of a corn-soybean rotation. A consistent 6.8 ± .08% of the total velvetleaf seedbank emerged each year. Less than 21% of all velvetleaf seedlings survived each year in mixture with soybean, due in part to Verticilium spp wilt infection. The probability of seedling survival varied across time of emergence Velvetleaf seed production in the absence of crop competition was 125 and 227 seeds plant-1 in 1992 and 1993, respectively. Velvetleaf plants that emerged early produced greater numbers of seed than later emerging plants. Velvetleaf survival and seed production were reduced up to 82% in the presence of crop competition. Soybean yield varied across soybean densities in both years, but was not reduced across velvetleaf densities. Nomenclature: Velvetleaf, Abutilon theophrasti Medicus. #3 ABUTH; soybean, Glycine max (L.) Merr. \u27Evans\u27; corn, Zea mays L

Modeling the Population Dynamics and Economics of Velvet leaf (\u3ci\u3eAbutilon theophrasti\u3c/i\u3e) control in a Corn (\u3ci\u3eZea mays\u3c/i\u3e)-Soybean (\u3ci\u3eGlycine max\u3c/i\u3e) Rotation

A simulation model was developed to predict the population dynamics and economics of velvetleaf control in a corn-soy bean rotation. Data compiled from the literature were used to parameterize the model f or two situations, one in which velvetleaf was infected by a Verticillium spp. wilt and one without infection. Verticillium was assumed to have no effect on corn or soybean yield. In the absence of control, simulated seed bank densities of a Verticillium-infected velvetleaf population were 5 to 50 times lower than for an uninfected velvetleaf population. The model was used to evaluate a threshold weed management strategy under the assumption that velvetleaf was the only weed and bentazon the only herbicide available for its control. In the absence of Verticillium, an economic optimum threshold of 2.5 seedlings 100 m-2 afforded the highest economic returns after 20 yr. of simulation. Simulations in which velvetleaf was infected in 8 out of 20 randomly assigned years indicated a 6% increase in annualized net return and an 11%reduction in the number of years that control was necessary. Sensitivity analysis indicated the parameter estimates having the greatest impact on economic optimum threshold were seedling emergence and survival, maximum seed production, and herbicide efficacy. Under an economic optimum threshold of 2.5 seedlings 100 m-2, management practices that manipulate the most sensitive demographic processes increased annualized net return by up to 13 % and reduced long-term herbicide use by up to 26%. Results demonstrate that combining an economic optimum threshold with alternative weed management strategies may increase economic return and reduce herbicide use. Nomenclature: Bentazon [3-(1-methylethyl)-(1H)-2,1,3-ben-zothiadiazin-4(3H)-one2 ,2-dioxide]; velvetleaf, Abutilon theophrasti Medicus #3 ABUTH; soybean, Glycine max (L.) Merr. \u27Evans\u27; corn, Zea mays L

Herbicide mode of action and injury symptoms (Revised 1991)

1 online resource (PDF, 16 pages)This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu