2018 Competitive Grant Summaries
2018 Competitive Grant Summaries
Optimizing apple thinning
Fruit thinning is an essential practice for achieving marketable fruit size, optimizing fruit quality and ensuring consistent return bloom. Failure to thin reduces profitability in the current season due to an overproduction of small fruits of low value and in the subsequent year as a result of poor return bloom. Decades of research has led to the development of several chemical thinners for apple with varying modes of action, yet thinning remains enigmatic – a blend of science and art with an often unpredictable outcome. To further complicate the situation, proven thinning chemistries have uncertain futures due to changing regulations. First, Todd Einhorn, an associate professor in the Department of Horticulture, and his team will conduct multiple thinning trials using a range of sites and cultivars. The team is seeking to develop new thinning compounds that achieve thinning in early and mid-timings, as well as late timings for rescue thinning. Second, researchers are developing a novel method to improve the precision crop load management procedure by photographically imaging hundreds to thousands of fruits daily. They will then analyze the images to calculate daily fruit growth rate and, ultimately, enable the early estimate of abscission probabilities. Einhorn said that these efforts will directly improve profitability, increase production efficiency and improve fruit quality.
Identifying genes for stripe rust resistance in elite Michigan wheat varieties
Stipe rust is a yield-limiting disease of wheat that can significantly reduce the profitability of wheat farming operations during epidemics. The MSU wheat breeding program has identified a set of lines with high levels of resistance to stripe rust. The genes conferring resistance can be localized to chromosome intervals using association analysis. Three new resistance genes have been identified from a relative of wild wheat that can be fine-mapped to discrete physical intervals. The sources of stripe rust resistance and resources developed in this study will ideally sustain long-term profitability of wheat in Michigan through the development of resistant varieties. The 2016 epidemic provided an opportunity to evaluate the stripe rust resistance in 100 elite lines of the MSU wheat breeding program. Five replicates of stripe rust severity were evaluated on a 0 to 9 scale at three locations in Michigan: East Lansing, Mason and Richville. A high frequency of resistant lines were identified with severities lower than 6. A set of seven parents were common in the pedigrees of resistant lines. In addition to the scientific merits, this work has great potential to impact rural communities by increasing on-farm profitability. Protecting wheat yields delivers economic benefits across the entire wheat value chain in Michigan. Project lead Eric Olson, MSU assistant professor in plant, soil and microbial sciences, said that wheat growers will experience higher profitability on their farms by having improved wheat varieties available with high levels of resistance to stripe rust.
Epidemiology, biology and population genetics of oak wilt
The fungal pathogen that causes oak wilt is responsible for the widespread decline of oaks across the United States, including 24 states and 829 counties. It is particularly devastating to trees in the red oak group, which can succumb to this disease within four weeks of infection. Spread of this disease is rapid and occurs on multiple fronts from root-to-root transmission, insect transmission and sporadic long-range infections due to movement of firewood. The decline of oaks is an aesthetic blight across the landscape, requires costly tree removals and causes devastating ecosystem damage. There is no natural resistance to this disease in the red oak group. The only means of preserving these valuable trees is to reduce the spread of oak wilt to new locations and reduce inoculum load in known oak wilt-positive locations. This is particularly relevant to activities that result in tree wounding or movement (pruning, harvesting, thinning, utility line clearance and firewood). Currently, disease management decisions in Michigan are primarily based on research conducted in other states and anecdotal observations. This project is looking at evaluating whether effective molecular methods of detection are available. Researchers are also trying to determine key periods of oak susceptibility to infection, including when those trees are exposed to insect vectors of the disease.
Integrating fall-planted cereal cover crops to aid in the management of glyphosate-resistant horseweed
Horseweed, also commonly known as marestail, is a weed that was not on the radar of most Michigan soybean growers 10 years ago. However, over the last five years this weed has become a major concern. Extended emergence and the development of resistance to glyphosate and other herbicides have made horseweed management a challenge, especially in soybean. Horseweed is an annual weed species that was historically classified as a winter annual since the majority of seedlings emerged in the fall. However, more recent studies and observations have shown higher numbers of horseweed plants emerging early in the spring. Researchers are evaluating the effect of the fall-planted cover crops, cereal rye and winter wheat, at two seeding rates on the suppression of glyphosate-resistant horseweed in no-till soybean. They are then comparing the integrated approach of the combination of cover crops and different herbicide strategies with the herbicide programs alone. The continued spread of glyphosate- and multiple-resistant horseweed will have a detrimental effect on the economics of Michigan crop production. Plant, soil and microbial sciences professor Christy Sprague, the project lead, said that this research is important to provide effective information to soybean growers on management of this economically significant weed problem. It also provides alternative options, in addition to herbicides.
Climate change-induced changes in the phytobiome: Implications for disease management in the 21st century
Plants and microbes have a complex relationship within their environments, as both complementary and adversarial. Whether a microbe is or has the potential to be pathogenic is attributable to the evolutionary and adaptive pressure on both the microbe and the host. However, a key and essential factor governing the outcome of a plant-microbe interaction is that of the environment. Corn, an industry worth $1.2 billion in Michigan, is a major agricultural commodity crop in which disease affects grower productivity. It is clear that climate conditions have changed in the last century in Michigan, and based on future climate predictions, a warmer growing season is expected. It is the hypothesis of the researchers that climate change has had a key role in changing the composition of the phytobiome and contributes to not only the emergence of new diseases but also to the severity of diseases in agricultural systems. The team designed a research study to collect empirical data to develop predictive models on how pending climate change will have an impact on the corn phytobiome and to demonstrate how historical and future climate conditions affect key diseases of corn. First, researchers are characterizing the historical composition and profile of the corn soil phytobiome and modeling how historical climate variability and change influenced the composition of the phytobiome. Then, they will experimentally demonstrate the impacts of historical and future climate on key disease pathosystems of corn. Data from this project will be disseminated to Michigan corn growers through presentations at stakeholder meetings and through publications.
Improving nutrient management for Michigan agriculture through enhanced online decision support and extension
Nutrient loss from agricultural fields is a pressing challenge that harms both farm profits and the environment. Recent water quality issues in Lake Erie and elsewhere highlight the importance of sound nutrient management for protecting our water resources. The U.S. Department of Agriculture Natural Resources Conservation Service’s recent $77 million investment in the Western Lake Erie Basin Initiative identified avoiding excess nutrient application as the first of four key strategies for addressing this problem. In addition, inefficient and excessive fertilizer nutrient applications can lead to higher input costs and potential yield losses for farmers, costs that may be exacerbated by more frequent extreme weather events in the future. Sound nutrient management rests on understanding both the current fertility status of the soil and specific crop demands. Testing the soil and fertilizing according to science-based nutrient recommendations is the foundation of minimizing nutrient losses – including that of phosphorus and nitrogen – while maximizing productivity. Growers across Michigan’s plant agriculture sectors rely on Michigan State University as a resource for accurate, research-based nutrient recommendations. Researchers and MSU Extension specialists are preserving and upgrading the MSU Nutrient Recommendation Program – a novel, web-based decision support tool for obtaining crop-specific fertility recommendations from soil test results. Then, they are pursuing a cross-commodity outreach effort to promote responsible nutrient management while expanding awareness and use of the modernized NRP tool. As a result of increased knowledge and enhanced decision support, potential impacts for growers and the environment include more accurate fertilizer management, cost savings, yield gains, increased profits, reduced nutrient losses from fields, and improved quality of surface and groundwater resources.
Developing a long-term strategy for cover crop research in Michigan’s Upper Peninsula
Although the benefits of cover crops to soil health are widely accepted, the practice is not often used in Michigan’s Upper Peninsula because of the perception that there is little time to establish a fall cover crop after harvest due to a narrow growing season. That perception is beginning to change as more farmers are struggling with maintaining soil health and exploring new opportunities to maximize productivity. The U.P. is a diverse region, both in terms of landscape and the agricultural industries it supports. The challenging climate limits the scope of crops that can be grown and has kept many farmers from adopting soil health improvement practices, such as planting fall cover crops following harvest. The U.P. soil, degraded due to intensive tillage and nutrient mining, has potential for improvement and increased productivity through the use of cover crops. Their ability to improve the biological, chemical and physical soil properties can improve nutrient efficiency in the system. Two separate trials are being used to better understand the feasibility of cover crop use in the U.P. and to target appropriate crop species, seeding dates and management. Trial one addresses interseeding of cover crops – a management tool used to overcome the challenge of a short season after silage harvest. Trial two examines cover crop species and their success and effectiveness based on seeding date. Through these efforts, researchers hope to strengthen relationships among farmers, the MSU research community and conservation professionals serving the area.
Michigan hop growers face several disease challenges
Hop is a perennial specialty crop grown for use in beer production. Michigan is the largest hop producer outside the Pacific Northwest, and harvested hop production acreage doubled from 320 acres in 2015 to roughly 800 acres in 2016. Michigan’s hop industry was valued at $16.4 million in 2016. Downy mildew is the most significant disease affecting hops. All parts of the plant can become infected, and crown rot can cause total yield loss. Downy mildew populations are prone to develop resistance to multiple fungicides, which complicates management. Viruses are also a significant and limiting problem for hop production, and viral infections can result in substantial yield loss. All Michigan hop propagators tested positive for at least one of five viruses in preliminary tests. Hop seedlings infected with downy mildew or viruses while in the nursery should not be used to establish hopyards, but infected plantlets may not show symptoms. Project lead Mary Hausbeck, University Distinguished Professor of plant, soil and microbial sciences, said that because of this, disease management strategies and cultivar selection specifically tailored to Michigan need to be developed. The research team is developing a management program for Michigan that samples nurseries and tests for viruses. The team will identify fungicides effective against downy mildew and evaluate hop cultivars. Through MSU Extension, the group will work to educate growers, implementing outreach strategies to disseminate information.