SAES-422 Multistate Research Activity Accomplishments Report
Sections
Status: Approved
Basic Information
- Project No. and Title: NC1026 : Characterize Weed Population Dynamics for Improved Long-Term Weed Management Decision Making (NC202)
- Period Covered: 10/01/2007 to 09/01/2008
- Date of Report: 09/24/2008
- Annual Meeting Dates: 07/29/2008 to 07/30/2008
Participants
Sharon Clay (SD); John Cardina (OH); John Lindquist (NE); Christy Sprague (MI); Doug Buhler (Administrative Advisor, MI); Adam Davis (IL, USDA-ARS); Anita Dille (KS); Analiza Haydee Ramirez (KS); Joel Felix (OR); and Jack Dekker (IA)
The annual meeting was held at the Lied Conference Center, Nebraska City, NE on July 29-30, 2008. The meeting started with a reminder from the research group advisor that the current NC1026 project will expire in September 2010. One option is to rewrite the proposal for renewal; in which case the revised proposal will need to be in the system by December 2009. The other option is to prepare a new proposal to address other issues that will hopefully build onto previous research topics. After a long discussion, it was agreed that the group members will brainstorm and meet again during the 2008 North Central Weeds Science Society (NCWSS) and or the Weed Science Society of America (WSSA) meetings to decide on the next move. Researchers presented reports on the ongoing research objectives. It was suggested that analyzing the demography data (Objective 1a) using Julian weeks (instead of thermal time) may help to tease out weed emergence opportunity spaces at each test site. It was agreed that different data analysis considerations will be looked at by those leading preparation of manuscripts for publication. It was further noted that participation in the NC1026 research project needs to be improved by recruiting new members. There was a consensus that a letter be sent out to particular individuals (and current members who did not attend the meeting) with an invitation to attend the brain storming meeting at the NCWSS and WSSA. The next group meeting will be held at Kellogg Biological Station, Hickory Corners, MI. from July 27-29, 2009.
[Minutes]
Accomplishments
The overarching goal of the NC1026 project and its multi-state group of collaborators is to determine the importance of representing demographic realism within weed decision support systems (DSS) and to facilitate incorporating the information that can best help to improve weed management decision-making. Over the course of the last two years, the most widely used weed management DSS, WeedSOFT, was overhauled to determine the importance of how weeds that survive management treatment affect decisions recommended by the software. Our examination revealed that some fundamental processes, such as a lack of synchrony in weed emergence, were not and could not be represented within the current framework. Therefore, we initiated a plan to create a simplified version of WeedSOFT and compare its decision-making performance with a set of more demographically realistic alternatives in order to assess the value of changing how it represents weed-crop competition and the response of weed populations to various management interventions. The WeedSOFT program itself is currently under revision for distribution via the worldwide web. A grant from the NC-IPM was received in 2008 to support efforts to rebuild WeedSOFT as an Internet-based integrated weed management decision tool that will be available free of charge to the users.
The group also accomplished a great deal experimentally. Five collaborators have conducted the demography experiment (Objective 1a) over two growing seasons. The demography information provided by the regional experiment will provide a means for assessing the importance of modifying the structure of a DSS like WeedSOFT so as to incorporate a more realistic representation of the impact of weeds and how they respond to management. Progress reports from those conducting the soil training experiments (Objective 1b) were also very interesting and could strongly influence our assessment of the value of adding additional biological realism into weed decision support tools. If the weed decision support tools are to evolve beyond herbicide selection for different crop-weed scenarios, it will be through efforts like this regional project.
Impacts
- " Members of NC1026 continued to develop the computer-based decision support system, WeedSOFT, which is used by more than 500 users in 9 states over the last two years. Efforts are under way to develop a web-based version of WeedSOFT to enable a wider use of this valuable tool. Funding from NC-IPM has been extended to WeedSOFT programmers so as to expedite the process.
- " Previous research showed that multi-location studies throughout the region over multiple years provide better information for decision making than single location experiments.
- " NC1026 research showed that weed germination and emergence is environment specific and understanding the mechanisms controlling these factors are required to effectively predict where and when weeds problems will occur.
- " Members of NC1026 showed that weeds surviving sublethal doses of pre- and post-emergent herbicides often do not effect crop yield and produce substantially fewer seeds than untreated weeds.
- " NC1026 research has improved and strengthened the weed management recommendations of WeedSOFT and other decision-support software.
- " Members of NC1026 are now working to include this research-based information into educational modules for a web-delivered version of WeedSOFT.
- " NC1026 research created greater insight into how management strategies and environmental factors influence the degradation and longevity of weed seed banks.
- " NC1026 researchers showed that weed emergence patterns are similar in different test locations even when seeds from one location are grown in a new environment.
Publications
Terra, B. R. M., A. R. Martin and J. L. Lindquist. 2007. Corn-velvetleaf (Abutilon theophrasti) interference is affected by sublethal doses of postemergence herbicides. Weed Science 55:491-496.