Maryland IPM Report, 2021

NEERA meeting: April 23, 2021

Submitted by Kelly Hamby, MD IPM Coordinator


Maryland (MD) is a heavily urbanized, densely populated state bordering the Chesapeake Bay. Agriculture is the largest single land use in the state, with 32% of MD’s total land area used for farming. The proximity between agriculture, environmentally sensitive areas, and human populations necessitates the implementation of sustainable IPM practices that reduce risks to human health and the environment. MD produces a broad diversity of agricultural commodities.

Green Industries. The green industries encompass production and management of nursery, greenhouse, cut flowers, landscape plants, and turfgrass. In MD the green industries are the 2nd largest commodity with an estimated value of over $1.3 billion, nearly 30,000 acres in production including almost 500 acres of greenhouses, and over 300 plant production nurseries. Conventional green industry practices can have detrimental effects on the managed ecosystem resulting in increased pest outbreaks and costs to growers. Off-target impacts on the environment and human health may also result. Emerging invasive species continues to challenge plant production and maintenance, and the health of managed ecosystems. The University of Maryland Extension (UME) Master Gardener program plays a significant role in educating homeowners on issues related to the planning, design, installation, and maintenance of home gardens and landscapes. Master Gardeners need to be educated on research-based sustainable approaches to managing pests in home landscapes.

Pollinator Protection. A recent MD state initiative was developed to provide landowners cost- share to establish buffer habitats that are hospitable to pollinators. This new law and Conservation Reserve Program (CRP) initiative provides an opportunity to engage new clientele in pollinator conservation and habitat restoration. However, there is a clear need to first get communities fervent about pollinators partly by educating them on their important contributions.

Weed Management. Weeds are an important concern to MD vegetable farmers. Integrated weed management (IWM) programs are not well developed or widely practiced in MD vegetable production. As such, conventional and organic farmers in MD depend heavily on herbicides and tillage, respectively. Thus, it is vital that producers become more knowledgeable on IWM tools and the importance of adopting an IWM program. Herbicide resistant weeds also continue to be an issue in multiple production systems.

Agronomy. In 2020, roughly 19% of MD’s total land area was planted in field crops (1,510,000 acres), which were valued at $688,000,000 dollars in 2019. Climate change, emerging and invasive pests, pest resistance, and rapidly developing production technologies require timely responses for this important sector to maintain profitability. To improve water quality in the Chesapeake Bay watershed, MD growers abide by some of the most stringent regulations governing the timing, method, and amount of nutrients applied to agricultural land in the US [2]. IPM’s science-based decision-making helps producers increase profitability while protecting human health and the environment. Encouraging adoption of better management practices will help stakeholders face today’s production challenges.


University faculty, staff, and other IPM partners conduct applied research to evaluate the efficacy of pest management practices and to develop novel sustainable tactics. Our recent Extension Implementation Program submission included Agronomic Crops (30% of budget; 5 co-PDs), Communities (10% of budget; 2 co-PDs), Specialty Crops - Vegetables and Fruits (17% of budget; 2 co-PDs), Specialty Crops - Green Industry (12.3% of budget; 3 co-PDs), Pollinator Health (21.7% of budget; 2 co-PDs) and IPM Coordination (9% of budget; 2 co-PDs) priority areas. We support additional research and extension efforts with funding acquired from commodity boards, non-profits, and government sources at the local, state, regional, and national levels. Much of our work is performed in collaboration with stakeholders to develop practical solutions that will be adopted. We also perform demonstrations on stakeholders’ properties as well as at University facilities to encourage adoption of best management practices. We educate face-to-face at extension meetings, field days, workshops, train-the- trainer events, in-service trainings, and through booths at events. Numerous print and web- based newsletters, publications, announcements, and updates are provided in addition to media broadcasts, social media presence, online videos, and other approaches to disseminate timely research-based information. University of Maryland Extension is currently assessing the needs of its staff and faculty to determine the infrastructure and knowledge needed to expand our ability to telecommute and deliver programming online.

Outputs and Impacts

Green Industries

  • Demonstration research on augmentative release of native parasitoids an assessing the impact on biological control of brown marmorated stink bug.
  • Citizen Science project to identify alternate insect hosts of native parasitoids associated with brown marmorated stink bug; and the host plants that support a key native parasitoid to inform the development of successful biological control practices. Fifty Citizen Scientist have volunteered, been trained, and are collecting data for this project.
  • Evaluating interactions between native and introduced natural enemies and their impact on invasive species.
  • Results from these studies should lead to long-term sustainable management of BMSB.
  • Results from these studies and on the management of BMSB have been presented at numerous local, regional, national and international stakeholder meetings.
  • Conducted training for over 1,200 participants from the green industries and master gardeners (2020-present) through stakeholder and extension sponsored conferences.
  • The Nursery and Landscape IPM Pest Report (web-based). The IPM Pest Report has been produced weekly since 2000 during the growing season (March – October). Since its initiation, the report has grown to over 4,000 weekly subscribers from 24 states. Surveys of the recipients show that the IPM Alerts help readers to better identify pests and beneficials, diagnose plant problems, select less toxic or alternative control measures, and reduce pest management costs.
  • The Pest Predictive Calendar (web-based; 2016-present). In response to survey feedback from stakeholders, we developed a “Pest Prediction Calendar” that uses degree days and plant phenological indicators to predict when life stages of key pests are likely to be active and could be targeted for intervention. In the first year that the IPM Pest Predictive Calendar was available on-line (2016), 32% of those surveyed used the IPM Pest Predictive Calendar to predict and monitor pest activity and make timely pest management decisions. It has become one of the most viewed features of the Commercial Horticulture Web Site.
  • Advanced Landscape IPM Short Course (taught annually). Dr. Raupp and Dr. Shrewsbury co-coordinate, and with other UME specialists (Dr. Rane, Dr. Clement, S. Gill) develop lectures and laboratory exercises for this multiday, 30 – 40-hour laboratory and lecture program that gives stakeholders the most up to date information on diagnostics and sustainable pest management tactics and strategies. Since 2005, this course has provided training for 694 attendees from more than 20 states and four countries.

Pollinator Protection

  • Improving health of managed bees, increasing pollinator habitat, approaches to encouraging natural pollination services (Dr. vanEngelsdorp, Dr. Hooks, Dr. Espíndola)
  • A seven-part series of extension publications were developed to help expand MD stakeholders’ knowledge of pollinators and enhance their interest in pollinator conservation (Dr. Hooks and Dr. Espíndola). The publication series discussed invertebrate and vertebrate pollinators ecology including their contribution to services in addition to pollination (e.g., biological control) and included information regarding how their populations can be protected and conserved. These articles were published in popular UMD extension newsletters and blogs. Vegetable and Fruit Headline and Agronomy News blog, to help promote pollinator knowledge, interest and conservation. These were read by ~2,500 and 3,000 stakeholders, respectively from each source.
  • To reach the large urban and suburban populations of the state, Dr. Espíndola contributes to the Maryland Grows blog providing information about pollination and pollinators. Her blogs are extremely well-received, with each of her posts receiving hundreds (and often thousands) of visits, and based on the most recent analytics they have cumulatively received over 14,000 visitors. These blogs have received public comments asking more questions, thanking her for the useful information, and creating a place where people can connect, share and grow jointly their knowledge. As a result of her posts, she has received personal emails from Extension agents, members of the community, thanking her for the publications and asking her to continue contributing. Further, these posts have led to the publication of other articles in the public media, such as that recently published by the Sierra Club.

Weed Management

  • Thus far seven extension publications covering IWM in vegetable crops have been developed and published in a MD stakeholder newsletter (Dr. Hooks). In addition to the newsletter, information regarding IWM in vegetable systems has been disseminated via field days, workshops, farm walking tours and commodity meetings held in person or via zoom to experienced and beginning farmers. These articles have helped expand stakeholders’ knowledge of IWM and demonstrated how various weed management options can be used as part of a synergistic weed suppression program. In FY 2020 supplemental monies were obtained from two USDA NIFA funding sources to conduct research aimed at enhancing IWM options in plasticulture vegetable production and another to create a novel cover cropping practice that can be used solo or synergistically with herbicides to effectively manage weeds and enhance natural enemy efficacy in sweet corn plantings. Since 2019 nearly 1000 stakeholders have become more knowledgeable on adopting IWM tools via presentations at conferences, field day, farm walking tour events and workshops.
  • Dr. Vollmer evaluated the effects of delaying cereal rye termination in combination with one-, two-, and three-pass herbicide programs in soybean. Delaying cereal rye termination to 2 weeks before planting or at-planting improved winter annual weed control and giant foxtail control, regardless of herbicides used or herbicide application timing. (Dr. Vollmer)
  • An Integrated Weed Management Workshop was hosted in December by University of Maryland Extension, Delaware Cooperative Extension, and Virginia Cooperative Extension. This workshop addressed developing trends in herbicide resistance, how to develop an integrated weed management plan, and farmer adoption of IWM tactics. The workshop had over 155 participants from CT, DE, MD, NJ, PA, VA, and WV.


  • Improved understanding and management of soils with high phosphorus concentrations, economic and environmental nitrogen fertilization decisions, and optimizing crop planting dates for a changing Maryland climate (Dr. Fiorellino). This includes evaluating industrial hemp to remediate soils with high phosphorus concentrations, understanding barriers to adoption of in-season nitrogen decision support tools by regional growers, and observing changes in pest populations when crops such as soybeans, wheat, and industrial hemp are planted outside their typical planting window.
  • Dr. Fiorellino currently co-leads industrial hemp production research program at University of Maryland, providing current and potential hemp growers with resources to successfully produce industrial hemp.
  • Determining biocontrol contributions of spiders in agricultural drainage ditches (Dr. Lamp)
  • Improving variety selection using statewide grain variety trials (Dr. Fiorellino)
  • Reducing insecticide use through better understanding of pest pressure and efficacy (Dr. Hamby)

Pest Diagnostics

  • Improving diagnostic capacity and training new agents using virtual plant clinics
  • The UMD Plant Diagnostic Laboratory directed by Dr. Karen Rane receives 500-800 plant samples each year from commercial growers, landscapers, arborists, consultants and county extension field faculty, for diagnosis of arthropod pests, infectious diseases and abiotic disorders. Diagnostic tests used in the lab include microscopy, microbiological isolation, ELISA, and molecular assays. Clients receive electronic reports of diagnoses and management recommendations. All diagnoses are uploaded to the National Data Repository of the National Plant Diagnostic Network (NPDN).

IPM in Fruit and Vegetable Crops

  • Identifying Colletotrichum spp. causing anthracnose in VA, MD, PA to detect potential spread of a more serious species and improve anthracnose management (Dr. Hu)
  • Evaluating and improving the strawberry advisory system as a predictor of real-time disease incidence (Dr. Hu)
  • Improving management of late season bunch rots (Dr. Hu)
  • Developing a fungicide resistance testing service for MD small fruit (Dr. Hu)
  • Improving spotted wing drosophila management in small fruit (Dr. Hamby)
  • Impact of management approaches on fruit quality (Dr. Farcuh)

IPM in Communities

  • Increasing homeowner adoption of IPM through Master Gardener programming
  • Establishment of a network of demonstration plots in suburban yards demonstrating effects of fall yard clean-up activities on overwintering predators and pollinators. (Dr. Burghardt)
  • Working with 4H forestry team subject matter coach on forest insects and pests (Dr. Burghardt)
  • Dr. Burghardt recently initiated a AFRI-NIFA project examining how the intraspecific genetic diversity and cultivar identity of street trees in Baltimore determines resistance to insect pests and abiotic stress. Results can be used by urban planners and nursery growers to enhance cultural control within IPM programs by choosing and propagating a selection of trees most likely to thrive in challenging urban environments.

Invasive Species Response

  • Increasing citizen awareness of spotted lanternfly (Dr. Lamp) and boxwood blight (Dr. Rane) issues
  • Providing a tick identification service to better understand Asian longhorned tick distribution (Dr. Fritz)

Climate Change

  • In 2020, Dr. Via gave a series of six “Climate and Sustainability” webinars that started with 325 registrants and ended with 1028. The videos have been viewed >4500 times in less than 8 months. Dr. Via asked people to complete a survey after each webinar and received >350 comments and overall excellent reviews.

Pesticide Resistance

  • Maryland (Dr. Dively lead, Dr. Hamby co-PD) leads a sweet corn sentinel monitoring network to conduct field evaluations of resistance to Bt proteins. In 2020, this network included 45 trials in 23 states (TX, AL, MS, FL, GA, SC, NC, VA, MD, DE, PA, NJ, NY, WV, OH, IN, IL, IA, NE, MN, WI, NH, and VT) and four Canadian provinces (ON, QB, PEI, and NS). Paired plots of Bt hybrids and non-Bt isolines established at each location effectively monitored field-evolved resistance in corn earworm (CEW) populations to Bt toxins, with particular focus on the Vip3A trait. The network provided evidence that Cry toxins are 80 to 90% less effective for control of CEW, compared to when first commercialized, and resistance continues to develop based on increases in kernel damage and number of surviving larvae in Bt ears. The Vip3A toxin still provides near 100% control of CEW, even under very high population pressure at most trial locations. Altogether, ear sampling reported a total 95 live early instars in 114 damaged ears of 13,913 Vip3A ears sampled (0.82% damaged ears). Results published to the December issue of the Journal of Economic Entomology have influenced EPA to make proposed changes to the insect resistance monitoring protocol for Bt crops.
  • Developing genomic monitoring approaches for diagnosing resistance (Dr. Fritz lead, Dr. Hamby co-PD)