Current Critical Issues Projects
To learn about the details of our Critical Issues grant opportunities, and how to apply, click here.
Understanding Palmer amaranth and Waterhemp Demography in Alfalfa for Sustainable Management
Project Director: Erin Burns — Michigan State University
Herbicides drastically changed the agricultural industry in the 1950s, while also unintentionally placing selective pressure on resistant weed populations. The weed species Palmer amaranth and waterhemp recently rose to weeds of prominence in the North Central region, due to rapid plant evolution, resulting in significant yield losses and cost increases. Waterhemp and Palmer amaranth have an extended period of emergence allowing for significant emergence late into the growing season in annual crops. Uncontrolled plants can produce large numbers of seeds (> 1,000,000) thus increasing the soil seedbank for subsequent years. Herbicide resistant populations are common for both species as 28 states in the United States have documented resistance.
No new novel herbicide modes of action have been introduced to the market for approximately 25 years, suggesting that herbicides appear to be non-renewable resources. Therefore, sustainable management by implementing integrated pest management strategies by optimizing efficacy and longevity of current effective control methods is necessary. Understanding the biology, morphology, and ecological patterns of target species in the specific environment where they are growing is critical knowledge necessary to implement this. In alfalfa, the presence of dense, competitive vegetation before the typical first emergence timing could delay early emergence, but the frequent harvest intervals and resulting disturbance and light canopy opening could intensify the timing of emergence to specific times of the season. The overall goal of this research is to understand the emergence, establishment, and survivorship of Palmer amaranth and waterhemp in established alfalfa to be utilized in future development of ecologically-based integrated management practices for these highly aggressive and troublesome weed species.
Soybean Cyst Nematode Resistance Management with Rotation, Cover Crops, and Manures
Project Directors: Marisol Quintanilla — Michigan State University
Soybean Cyst Nematode (SCN), is the most important pathogen of soybeans and is found throughout all soybean growing regions, causing estimated losses between $469 to $818 million, nationwide. While plant resistance is the most effective and commonly used control strategy against SCN, some SCN populations have adapted to the resistance. Moreover, some nematicides are labeled to control SCN, but additional control strategies are required to supplement the existing control strategies, especially considering that most nematologists have not found commonly used nematicide seed treatments to be very effective in reducing SCN numbers.
Evaluating a multi-faceted approach to SCN control will equip growers with an array of control strategies to slow down the process of developing resistance to resistant soybean varieties. Moreover, utilizing sustainable control strategies will improve soil health conditions and hopefully delay further resistance to SCN resistant cultivars. This group will research several alternative resistant cultivars, as well as the incorporation of cover crops and manure into a management system.
Developing Molecular Tool to Increase Throughput and Accuracy of Herbicide Resistance Weed Diagnostics
Project Directors: Eric Patterson — Michigan State University
The evolution of herbicide resistance is a complex problem that impacts food security, public health, and the value of property. One of the most effective techniques for managing resistance evolution is rotating herbicide modes and site of action so that resistance to any herbicide is not recurrently selected and spread to fixation. Accurate and rapid molecular diagnostics allow pest managers to make informed decisions about herbicide applications within the growing season, even allowing resistance to be predicted prior to herbicide application.
Assessing herbicide resistance in weedy species can be a time-and space-consuming task for diagnostic clinics. Once seeds reach the clinic, this screening process can take two or more months, depending on the species. That means it could take 6 or more months from the initial herbicide failure in the field until potential resistance is confirmed. It also risks introducing more potentially-resistant-seed into the seedbank as the grower waits to collect mature seed. The Federal IPM Coordinating Committee’s national research and technology development goals include development and delivery of rapid diagnostic tools to detect pesticide-resistant populations in order to better inform IPM practitioners. This project directly addresses that goal for growers in the North Central U.S. for managing weeds.