AgBioResearch

Managing Potato Common Scab through Breeding and Soil Biology

David Douches

In the US, potato common scab is a devastating disease and is the primary factor limiting market quality. Use of scab-resistant varieties provides the best method of control for the commercial grower and to supply a quality product to the market. Objectives were to optimize conventional breeding techniques and to quantify population densities and diversity of target rhizosphere microorganisms among potato varieties important in plant and soil health. Researchers have made a set of crosses between advanced breeding lines and varieties from MSU and four other breeding programs that should combine high yield, scab resistance, market-quality traits, high specific gravity and smooth round shape. Conducting potato breeding evaluation and selection under commercial field conditions has led to an increasing number of scab-resistant breeding lines of which some could advance to commercial status in the chip-processing and table markets. One variety is being named (Saginaw Chipper) and two other scab-resistant breeding lines are in the commercialization queue at this time. The methods for detecting microflora via DNA sequencing in a commercial field were developed. Additional fields with variation in scab pressure need to be conducted.

Building Pollinator-Supportive Landscapes for Michigan’s Diverse Agriculture

Doug Landis

Insect pollination is critical to production of many of Michigan’s fruit and vegetable crops. Producers of pollination-dependent crops typically rent hives of the European honey bee from commercial beekeepers to supplement the activity of native pollinators. However, both honey bee and wild pollinator communities are in decline, and the potential for loss of pollination services is of concern. Objectives were to screen pollinator-supportive plants for dry soils, develop methods for reliable establishment of pollinator-supportive plants on dry soils, and test the effects of dry soil plant mixtures on pollinator communities on fruit farms. Researchers established three common garden trials on sandy soils, at the Southwest Michigan Research and Extension Center, the Clarksville Research Center, and the Northwest Michigan Horticultural Research Center. Researchers identified 12 species of perennial plants for dry soil sites that in combination, provide season-long floral resources and are consistently attractive to pollinators and natural enemies. Native plant producers are including these species in pollinator mixes and experiencing increased demand for these plants.

Spruce decline in Michigan: Disease Incidence, causal organism and epidemiology

Andrew M Jarosz

Spruce trees are common throughout Michigan. In fact, spruce rank second in abundance and make up 12 percent of all urban and community trees in Midwestern cities. Michigan is a major nursery of landscape trees with annual sales exceeding $250 million. Conifers, including spruce, make up well over half of the nursery production acreage in our state. Spruce, especially Colorado blue spruce, have succumbed to a new disease called spruce decline, which is characterized by needle loss and branch mortality that is first evident on the lowest branches and over time progresses up the main stem. Researchers documented that spruce decline is caused by canker causing fungi in the Diaporthe genus. Colorado blue spruce is especially susceptible to the pathogen, and Norway and white spruce are moderately susceptible. We are now in a position to explore options for dealing with the spruce decline epidemic.

Increasing Celery Yields Begins in the Greenhouse with Healthy Transplants

Mary Hausbeck

Michigan ranks as the No. 2 producer of celery in the U.S., an industry valued at $18.9 million. Celery growers must deal with new (anthracnose) and old (crown and root rot) diseases. These diseases can attack celery seedlings during greenhouse production and can occur in the field causing severe production losses. Objectives were greenhouse scouting and pathogen diagnosis, identifying effective reduced-risk fungicides and/or biocontrol agents, providing data to registrants of key products, and implementing greenhouse disease management strategies. This project identified an effective biocontrol product that celery greenhouse growers can use immediately to protect their plants and ensure that only healthy plants are used to establish their production fields. A root rot pathogen previously unreported in Michigan that can negatively impact yield was detected in celery greenhouse seedlings destined for field production. Other root rot pathogens were also detected over the course of this study. Root rot disease was limited by a biocontrol product tested during this study that is labeled for use in the greenhouse to protect the yields in the field.

Determining the economic feasibility of malting barley in Northern MI through performance trials and malt characteristic analysis

Christian Kapp

There is increasing interest within Michigan amongst malt houses and craft brewers in sourcing locally grown malting barley for use in craft beer. Project objectives were to conduct a multi-location variety trial in order to evaluate varieties for yield performance and malt characteristics, commission a feasibility study for a small to mid-scale Michigan malt house, and deliver results through MSU Extension programs and applicable publications. The greatest impact of this trial is an increase in the knowledge of how certain varieties performed at each location. All sites experienced much different weather patterns throughout the 2014 and 2015 growing seasons. This research provided the opportunity to fine-tune selections of malting barley varieties that show an adaptation to the climatic conditions of Michigan.

Potato Late Blight: Host/pathogen interactions and management of invasive and established genotypes of Phytophthora infestans on foliage and tubers

William Kirk

The sudden appearance of a new genotype of Phytophthora infestans in 2009 devastated tomato production in the eastern U.S. Potato late blight is a significant global constraint to potato production and due to climatic conditions and growing practices in the upper Midwest make potato production particularly vulnerable. Objectives were to breed improved cultivars for the industry that have foliar and tuber resistance to late blight using a combination of conventional breeding, marker-assisted strategies and transgenic approaches. The release of cultivars with resistance to foliar and tuber blight will be of great economic benefit to the industry and to the environment and reduces the risk of threats to food security.

Effect of Nitrogen Rate on Runoff Water Quality from Turfgrass

Kevin Frank

There are at least 11 states that currently regulate fertilizer applications to turfgrass. Throughout the United States most fertilizer laws focus on improving surface water quality. With continually rising fuel and labor costs, professional lawn care operators may now consider fertilizer products that can be applied in one or two applications a year to reduce the number of fertilizer applications from the typical 4-6 to 1-2. Research found no detrimental effects from applying high rate applications of slow-release fertilizers on runoff water quality from turfgrass. As a result of this research, professional turfgrass operators could save up to 10 percent on application costs by making two applications of slow-release fertilizers in comparison to four applications of fast-release fertilizers and not risk compromising runoff water quality.

Solving the Challenges to Organic Raspberry Production

Eric Hanson

High tunnels are lower cost greenhouse-like structures that are increasingly popular for raspberry production because the provide a means of increasing yields, extending harvest seasons and reducing fungal diseases and damage from some insect pests. Profits from organic production under tunnels can be higher than for field-grown raspberries because of improved yields, berry quality and disease control. A critical challenge that limits the efficacy of high tunnel culture for organic raspberries is the invasive insect pest, spotted wing drosophila (SWD). Organic control is very difficult since approved insecticides provide only marginal control at best. However, harvest frequency may affect SWD infestation levels. Frequent harvesting may be less efficient, but costs may be offset by higher marketable yields. This research has demonstrated the efficacy of non-chemical approaches for managing spotted wing drosophila infestations in tunnel raspberries. These approaches can be used by organic and conventional growers to help manage this invasive pest, while reducing insecticide use by 50% or more.

Strategic Modernization of the Enviro-Weather IPM Information System for Fruit Production in Michigan

Jeff Andresen

The overarching mission of the Michigan State University-based Enviro-weather Project is the provision of relevant, dependable and sustainable weather-based information to support agricultural pest, production and natural resource management decision making in Michigan. Enviro-weather collects, processes and archives detailed weather data from a mesonetwork of 83 automated stations across the state and provides a web-based framework for its use in a variety of applications and products. The primary objective of this project was the replacement and modernization of existing weather station hardware and related equipment at seven station sites across northwestern lower Michigan within Enviro-weather’s observing network to help ensure the long-term dependability and reliability of the monitoring system. Modernization work at each of the station sites was carried out during the late summer of 2015 and completed by October 2015. Replacement supplies at each station site included a new datalogger, datalogger enclosure, solar panel and sensors for air temperature, relative humidity, rainfall, wind speed and direction, solar radiation, soil temperatures and volumetric soil moisture (both at two depths), and two leaf wetness grids.

European Brown Rot: Understanding Infection Parameters and Devising Control Strategies for a New Threat to Montmorency Tart Cherry Production

George Sundin

Michigan leads the nation in tart cherry production, and its growers produce approximately 70 percent of the total U.S. crop. Controlling fungal diseases of tart cherry is imperative to produce this economically important crop annually, and in an average year, growers apply six to eight fungicide applications per season to manage key diseases, such as cherry leaf spot and powdery mildew. However, in 2013, an outbreak of European brown rot (EBR) occurred on Montmorency tart cherries in northwest Michigan. The main impacts of this study were that we could report to tart cherry growers effective fungicides that could be utilized for EBR control, and fungicides that were not heavily used to control other tart cherry diseases. This result is very promising for the long-term health of all fungicides used on tart cherry. Our response to EBR through identifying effective fungicides for control and breaking down key wetting requirements for infection helped inform growers on the best methods for control and will better enable disease prediction and spray decisions in future years.

Physiological responses of creeping bentgrass to infection by a bacterial pathogen (Acidovorax avenae subsp. avenae)

Emily Merewitz

A major problem within turf management is the prevalence of numerous biotic diseases of creeping bentgrass, a common putting green and fairway turfgrass species on golf courses. Recently, the turf industry has been plagued by a highly damaging new bacterial disease named “Bacterial etiolation and decline” that causes severe damage to creeping bentgrass. The pathogen poses an imminent threat to the success of turfgrass managers and has already caused great economic losses. This disease is capable of causing devastating, reoccurring, and quickly spreading symptoms on golf course greens. By determining that plant tolerance to A. avenae, this information can be used to develop naturally derived treatment options. This means that less of an emphasis may be placed on synthetic pesticide inputs. The turfgrass industry, particularly golf course superintendents, will greatly benefit from the results obtained from this study.

Controlling Vine Yield and Improving Cluster Microclimate Fruit Composition and Quality of Pinot Noir Grapes Grown In Cool and Wet Climate

Paolo Sabbatini

This project investigated the effect of leaf removal treatments on Pinot noir grapevines grown at the Southwest Michigan Research and Extension Center. This canopy management technique is poorly used and understood in the industry, and there was no specific research done in Michigan prior to this project to evaluate the impact on fruit technological maturity. Tightly-bunched grape creates a condition in which the mechanical pressure of adjacent berries is more likely to disrupt protective natural cuticle waxes and lead to damaged berry skins, areas now open to a higher incidence of microbial attack. The objective was to determine whether early leaf removal (at pre-bloom, full-bloom and fruit set) can be consistently used as a tool for controlling yield, thereby decreasing cluster compactness and reducing the potential for bunch rot. This research determined that a quantified amount of leaf removal pre-bloom reduced fruit set and consequently produce a controlled reduction in cluster compactness, improving fruit technological maturity and harvest and reducing bunch rot.

Cover crops, compost, and polymer-coated urea for nitrogen, nematode and weed management in processing carrots

Daniel Brainard

Weeds are a major constraint to profitable carrot production because they reduce carrot yields directly, and can serve as alternate hosts for insect, disease and nematode pests. Herbicides have been the mainstay of carrot weed management, but development of resistance among several species means that growers are increasingly looking for non-chemical approaches to manage weeds, including cover cropping and crop rotation. The impacts of compost, slow release fertilizers and cover crops on carrot pests and profitability were examined in a series of field studies. Slow release fertilizers, grass-family cover crops and compost additions hold promise for improving the sustainability of carrot production systems.

Goss’ Wilt Of Corn: Analysis Of Epiphytic Growth On Corn Leaves And Systemic Invasion Of The Pathogen Clavibacter michiganesis subsp. Nebraskensis

George W. Sundin

Goss’s wilt is a devastating bacterial disease of corn caused by the pathogen Clavibacter michiganensis subsp. nebraskensis (Cm subsp. nebraskensis). This disease was first discovered in Nebraska in 1969, and through the 1970s and 1980s was restricted to Nebraska, Colorado, Kansas, Iowa, South Dakota, Minnesota, Wisconsin, and Illinois. However, since 2006, Goss’s wilt has begun spreading out of this eight state area and the range of this disease has expanded to Oklahoma, Texas, Wyoming, Louisiana, Indiana, Michigan and also into Canada. The best method of control for this disease is through using resistant corn hybrids, and this research provides virulence traits suitable for study in assessing differences in and resistance potential among hybrids.

Identify and Use Of New Genetic Resistance to Soybean Sudden Death Syndrome

Dechun Wang

Sudden death syndrome (SDS) reduced soybean production by over 444 million bushels from 1996 to 2010 in the U.S. Yearly loss from the disease was estimated at over $190 million. SDS first appeared in Michigan in 2008 and has been found in more locations scattered throughout most Michigan fields since then. With support from Michigan Soybean Promotion Committee, researchers evaluated over 300 soybean germplasm lines from the MSU soybean breeding program for SDS resistance in both artificially inoculated fields and natural heavy SDS-infected sites. This research identified DNA markers associated with SDS resistance. SDS resistance from resistance sources were transferred to elite soybean germplasm and the best SDS resistant lines were entered in 2016 Regional SDS trials in multiple states. One SDS resistant variety was released.

Impacts of Grapevine leafroll virus and Tobacco ringspot virus on Chardonnay vines and the role of potential vectors

Annemiek Schilder

Virus diseases are widespread in vineyards throughout the world. Plant viruses are mostly spread via vegetative propagation, although insect and nematode vectors are involved in the spread of some grapevine viruses. Grapevine viruses can be unrecognized causes of low yields and poor plant growth, as well as grapevine decline. Grapevine leafroll disease is a significant constraint to sustainable growth of the wine grape industry in Washington State. In 2011 and 2012, leaf samples from symptomatic grapevines in Michigan vineyards were tested by ELISA for 12 different viruses. Of these, 41% were positive for one or more viruses, including Grapevine leafroll viruses. Understanding the economic impact and risk of spread of grapevine leafroll virus will help growers make well-informed decisions regarding the value of virus-tested planting material as well as potential removal of infected vines/vineyards that have become uneconomical due to virus infection. Researchers noticed a growing awareness among growers of virus risk to grapes and ability to recognize virus symptoms. In addition, there is a growing recognition of the need for virus-tested vines and vector (such as mealybug) management.

Growing High-Value Propagules Under LED Lighting

Erik Runkle

Michigan is the largest producer of propagative floriculture materials in the United States, with wholesale sales in 2015 of $83 million. Most of these are seedlings, rooted liners and tissue culture propagules of annual bedding or herbaceous perennial plants that are intensively and commercially grown in controlled greenhouse environments from December through April. During this time, light intensity is a limiting factor and a substantial amount of energy is consumed to keep greenhouses warm. Therefore, high-intensity lighting and heating are significant greenhouse production expenses. Researchers identified the benefits of introducing far red and white light to a conventional LED spectrum to improve quality attributes of high-value propagules, including increased biomass, regulation of extension growth, earlier flowering, and creation of a more pleasant environment for workers. Researchers estimate that growing high-value propagules under LED lighting can reduce production costs by as much as 25 to 40 percent, but the actual values are highly situational depending.

Can high-value beech trees be protected from beech bark disease with a recently developed, systemic azadirachtin insecticide?

Deborah McCullough

American beech is a common landscape tree in many residential and urban areas of Michigan, the northeastern U.S. and parts of eastern Canada. Unfortunately, beech in landscapes and forests are threatened by beech bark disease (BBD), a pest complex consisting of an invasive insect, beech scale and invasive fungi. Beech scales are tiny, sap-feeding insects that pierce the outer bark of beech trees to feed on phloem parenchyma cells. Wounds left by scales provide entry sites for the fungus, which causes internal cankers, killing branches and eventually the tree. Researchers evaluated whether TreeAzin, a recently developed systemic azadiractin product, could effectively control beech scale to protect valuable beech amenity trees from beech bark disease. Trunk injections of TreeAzin (azadirachtin) significantly increased beech scale mortality compared to untreated trees, but do not appear to provide sufficient levels of control to protect beech amenity trees from beech bark disease. Preliminary data indicate trunk sprays of either a dinotefuran insecticide or a non-toxic surfactant may provide nearly complete control of beech scale and warrant further study.

Physiology and morphology of street trees in response to elevated temperatures

Bert Cregg

Based on current trends of greenhouse gas emissions, summer temperatures in the Great Lakes region are projected to increase by 4-8oC (7-14oF) by 2070-2099. If greenhouse gas emissions continue to increase, summer rainfall in the region is projected to decrease by 20 percent. Selecting trees that are adapted to changing environmental conditions is essential to the future of urban and community forestry in Michigan and the Midwest. The long-term goal of the project is to identify shade tree genotypes with a high capacity to acclimate to changing environmental conditions. Urban trees provide a host of critical ecosystem services including improved air and water quality, building energy conservation, cooler air temperatures, reductions in ultraviolet radiation, and many other environmental and social benefits. Species are able to tolerate dehydration and maintain the ability to photosynthesis (Callery pear and swamp white oak in this study), may be particularly well-suited for stressful urban sites.

Managing Cercorspora Leaf Spot: Development and Growth Responses in Cercospora Beticola to Temperature

William W. Kirk

Cercospora leaf spot (C. beticola) is the most serious foliar disease of sugarbeet in Michigan. When conditions are conducive, Cercospora leaf spot can cause yield losses due to reductions in root weight, sugar content and purity. Control of Cercospora leaf spot includes use of disease-tolerant varieties, monitoring weather conditions to assess risk of disease development and use of fungicides to prevent and manage infection. Research in other areas has shown that extended periods (days) of high temperature can slow or stop growth of C.beticola. This is longer than occurs normally in Michigan, and there has been little or no research on the effect of exposure of less than 24 hours of high temperatures on C. beticola growth and development. The purpose of this project was to examine high temperature exposure of two to eight hours on the fungus. The determination of high temperature effects on the growth, sporulation and fungicide sensitivity of C. beticola can inform the current forecasting model.

Conversion of Michigan Agricultural Residues to High Value Furan Derivatives

Dennis Miller

There is a need to increase the value of Michigan agricultural products in order to improve the overall state of the agricultural economy in Michigan. This project develops new chemical routes using agricultural residues as raw materials to make high-value chemical products useful as ingredients in new types of plastics and as biofuel components. The research conducted in this Project GREEEN effort represents a first step in developing added value to agricultural processing in Michigan via utilization of waste residues. Furandicarboxylic acid and diformylfuran have been produced from agricultural-based raw materials in good yields using novel processing methods. This work provides a foundation for further investigation to enhance the Michigan agricultural economy and to reduce our society’s ubiquitous dependence on petroleum.

Advancing knowledge of blueberry pathogens and fungicide timing for effective disease management

Annemiek Schilder

Blueberry growers rely on chemical crop protection products to produce high-quality blueberries. Sterol inhibitors fungicides, such as Indar (fenbuconazole), Orbit (propiconazole), and Quash (metconazole) are the mainstays for mummy berry control but may have endocrine effects. In addition, sterol inhibitors have a single-site mode of action, which makes them prone to resistance development in target fungi. Despite the importance of the anthracnose and mummy berry pathogens, relatively little is known about the population diversity of these pathogens in Michigan. With advances in understanding of blueberry pathogen diversity and fungicide resistance as well as fungicide efficacy at peri-bloom timing, this project has a direct impact on disease management and fungicide recommendations for blueberries in Michigan and could, potentially, positively impact bee health and reduce environmental fungicide residue levels. The anthracnose fruit rot fungus in blueberries was determined to be C. fioriniae while the identity of the mummy berry fungus is still under investigation and will require DNA analysis of 100-year-old herbarium specimens. We detected a slight shift towards reduced fungicide sensitivity in the mummy berry fungus but no resistance was found. Fungicides were effective in preventing but not curing fruit infection.

Producing Greenhouse and Nursery Plants that are Safe for Pollinators in the Yard and Garden

David Smitley

In 2013 and early 2014 protests, publications, press releases and advertisements targeted retail stores and garden centers as selling flowers, trees and shrubs that are toxic to bees. A 2013 publication says that “gardeners may be unwittingly purchasing toxic seedlings and plants attractive to pollinators for bee-friendly gardens, only to poison them in the process.” Staged protests at selected garden centers of a large retail chain demanded that the stores remove neonicotinoid insecticides from their shelves, and not sell plants treated with neonicotinoid insecticides. Researchers found through a complete review of the scientific literature that greenhouse and nursery plants sold at garden centers have little impact on managed colonies of honey bees, and in fact provide food for honey bees and other pollinators as long as homeowners avoid spraying insecticides in the yard and garden. Overall, flowering plants in urban areas are probably more beneficial than harmful to honey bees and other pollinators. More research is needed to determine which types of annuals and perennials are most beneficial to bees, and to determine the impact of pest management practices during production on pollinators after plants are sold.

Vegetable Uptake of Pharmaceuticals from Soil and Water

Hui Li

Consumption of pharmaceutical-tainted fresh produce, particularly eating raw vegetables, represents a direct route of human exposure to pharmaceuticals. The sources of pharmaceuticals in vegetables can be tracked to contaminated agricultural lands and irrigation water. The overarching objective was to elucidate the mechanism of vegetable uptake and accumulation of pharmaceuticals from water. Researchers measured uptake and accumulation of 15 target pharmaceuticals in lettuce roots. These studies demonstrate the ability to quantify the distribution and accumulation of certain pharmaceutical chemicals in vegetables, and provide some interesting mechanistic insight into the primary determinants of such distributions. However, much work remains to gain a comprehensive mechanistic understanding of pharmaceutical uptake by vegetable crops.

Transcriptome Profiling to Understand Molecular Mechanism of Compatibility and Incompatibility in Bean-Anthracnose Pathosystem

James Kelly

Bean anthracnose is a major constraint for dry bean production wherever cool and humid environmental conditions prevails during the cropping season. Because of high pathogenic variability, the majority of bean genotypes are susceptible to one or other race(s) of pathogen. The focus of this study was to conduct a detailed RNA-sequencing analysis of the P. vulgaris-C. lindemuthianum pathosystem to discover genes and their associated processes that are regulated during the compatible and incompatible interactions and identify genes underlying pathogenicity and resistance in the P. vulgaris-C. lindemuthianum interaction. Candidate genes that condition resistance to bean anthracnose were identified in the resistant bean genotype. Knowing the mode of action of these genes in controlling anthracnose should provide bean breeders with better insights into developing future varieties with more durable resistance.

Postharvest noninvasive classification of tough-fibrous asparagus using computed tomography

Daniel Guyer

Asparagus is an important vegetable crop for producers and consumers in Michigan. An issue of undesirable fibrous tissue in fresh and processed asparagus exists. The issue is in part a result of tissue lignification through aging of the asparagus spears. Production variables, cultivar selection, invasive assessment methods and postharvest treatments have been attempted to alleviate the problem but have not proven fully and consistently successful. Researchers aimed to provide the Michigan asparagus industry with advancements that will allow them to market a high-quality product, and subsequently assist the asparagus industry in sustainability, through accessing continued and new technology utilizations. The study demonstrated computed tomography as a potential concept and nondestructive postharvest tool for discerning between asparagus spears having undesirable tough-fibrous tissue versus non-fibrous spears.

Exploiting the Landscape of Fear as an Insect Control Tactic

Christine Bahlai

Many recent studies have shown that insect herbivores exhibit fear-based responses to predators in ways once thought limited to higher taxa (e.g. vertebrates). For example, insect herbivores can detect visual and chemical cues identifying the actual or potential presence of predators. They adjust their behavior in response to these cues, altering patterns of movement, feeding and reproduction. Researchers proposed objectives to characterize the response to real and perceived predation risk. Non-consumptive, fear-mediated effects on pest insects are important, because they can reduce pest population growth. These effects can be demonstrated in both lab and field, but further experimentation is needed to determine how they interact with other landscape effects to be manipulated to help Michigan farmers reduce pest damage.

Evaluation of storage alternatives for Honeycrisp and other CO2 sensitive varieties

Randolph Beaudry

Several important apple cultivars are highly sensitive to the storage atmosphere, particularly the concentration of CO2, and can develop severe internal injury. Among those important to Michigan are Honeycrisp, Empire, Fuji, Braeburn and Jonathan. Among these, the Honeycrisp apple is the most profitable apple grown on a large scale in Michigan and acreage is continuing to increase rapidly. As the market share for Honeycrisp continues to expand and the acreage continues to grow, issues concerning production, storage and marketing are becoming increasingly important to the Michigan apple industry. Researchers found that storage operators can prevent controlled atmosphere injury in Honeycrisp and Empire apples using markedly reduced levels of the antioxidant diphenylamine. The use of air storage in combination with the ethylene action inhibitor 1-methylcyclopropene reduced injury relative to controlled atmosphere (CA) storage, but did not provide complete suppression of CA injury.

Aster yellows detection in leafhoppers to provide management solutions to Michigan plant industries

Zsofia Szendrei

Aster yellows phytoplasma (AYp) is a disease that infects vegetable crops such as carrots, celery and lettuce, making them unmarketable. The aster leafhopper is the primary vector of AYp, and control of the disease depends on managing the leafhoppers. The project’s objectives were to collect leafhopper samples from Michigan carrot and celery farms, test leafhoppers for aster yellows infectivity in the laboratory, and communicate leafhopper infectivity results to growers. Researchers collected 2,262 leafhoppers using sweep net method between May and Aug. 2015, representing 27 different fields at 15 commercial farms in 10 counties. The proportion of leafhoppers carrying aster yellows disease was determined, and researchers calculated a threshold for insecticide application and communicated results to growers in several different ways.

Further Evaluation of a Solid Set Canopy Delivery System for High-Density Apples

Matthew Grieshop

The goal of our seed project was to further test and refine a prototype Solid Set Canopy Delivery System (SSCDS) for high-density apples. SSCDS can reduce the energy and labor inputs for foliar applications by eliminating tractors and drivers and improve growers’ ability to utilize more selective, reduced risk pesticides and horticultural inputs. This also reduces spray drift and provides new strategies for orchard microclimate manipulation, which protects against rapidly changing weather patterns. An SSCDS was evaluated for spray coverage, a second system was prototyped to reduce spray wastage, and the potential to reduce insecticide active ingredient through rapid reapplication was evaluated. The new system provided adequate spray coverage, the new prototype reduced wastage by 80 percent and preliminary data suggests that reduced rate applications following a full rate application could maintain better coverage and reduce total active ingredient needed to control codling moth — a key pest of apples.

Advanced IPM Scout Training for Underserved Berry Growers to Manage New Invasive Species SWD/BMSB

Carlos García-Salazar

Since 2012, berry production has been affected by challenges undermining the sustainability of Michigan’s small farming operations. These farms provide income and employment to a large number of underserved and minority growers. Challenges faced come from new invasive pests due to increased international trade and travel. Blueberry and raspberry production are two major small fruit production activities supporting small fruit growers in Michigan and other Midwest states. The arrival of the Brown Marmorated Stink Bug (BMSB) in 1998 and the Spotted Wing Drosophila (SWD) in 2008 are devastating the fruit industry of fruit growing states. Objectives of this project were to develop and implement an experiential learning curriculum and to develop online resources, “Advanced IPM Program for SWD/BMSB Management and Control in Berry Crops.” Growers learned to use a systems approach to successfully manage the invasive SWD by learning the in-depth characteristics of recommended insecticides, the effect of weather conditions on its performance, and how to use Enviro-weather coupled with the life stage of the pest at the time of application.

Cultivar Screening of Creeping Bentgrass Exposed to Drought Stress

Emily Merewitz

Drought stress is an environmental stress that is highly damaging to turfgrass areas. Golf course putting greens and fairways are particularly susceptible to drought stress due to environmental factors such as the low mowing height, the tendency of turf managers to maintain putting greens on the dry side for optimal golf play conditions, and naturally occurring drought episodes. The objective of this project was to screen 20 cultivars of creeping bentgrass for variation in drought tolerance in both field and growth chamber settings. The top performing creeping bentgrass cultivars under drought stress included Pure Distinction and Flagstick. The bottom performing cultivars included Penncross and L93. Researchers indicated that ranking should be considered when selecting or recommending cultivars for use in areas that may encounter dry conditions.

Hop Research

Mary Hausbeck

In 2013, Michigan had 200 acres of commercial hops, 10 harvesting centers and eight processing operations. In 2016, Michigan has 1,033 acres of commercial hop production, and the hop industry is estimated to be worth $16 million. Some diseases, such as downy mildew, have resulted in yield and quality losses of up to 100 percent in other hop producing areas. Hausbeck assessed the current state of the Michigan hop industry and determine where research is needed. Significant pathogens were identified as a result of this project and a Crisis Exemption was obtained for a needed fungicide to limit a devastating disease outbreak.