Delaware IPM Report, 2021

NEERA meeting: April 23, 2021

University of Delaware | Delaware State University

IPM Team Members

Mark VanGessel – Extension Weed Science
Alyssa Koehler – Extension Plant Pathology
Brian Kunkel – Extension Entomology, Horticulture
Rose Ogutu – Horticulture Specialist, DSU
David Owens – Extension Entomology, Agriculture
Tracy Wootten – Horticulture Extension Agent
Carrie Murphy – Lawn and Garden Program Leader
Emmalea Ernest – Agriculture Program Leader

General Comments and Current State

Delaware integrated pest management activity is focused on agronomic crops (corn, soybean, sorghum, wheat, and barley), specialty crops (sweet corn, legumes, cucurbits) and community IPM (tree health and high tunnels). Funding is provided by the state, specialty crop block grants, commodity groups (Delaware and Maryland Soybean Board, Maryland Grain Producers Utilization Board, MarDel Watermelon Association, Pennsylvania Vegetable Marketing and Research Program), Northeast IPM Center, USDA NIFA, Sustainable Agricultural Systems, and USDA SARE.

The coronavirus pandemic markedly impacted IPM programming and there was a temporary hiring freeze for all workers. Many of our long-standing programs made rapid adjustments to deliver content virtually. Virtual programming was met with mixed results. A virtual field day was attempted in August, but audience engagement was very limited. Virtual delivery of MidAtlantic Crop Management School in November was well attended and well received (as was the 2021 virtual Delaware AgWeek). The multi-state Herbicide-Resistant Workshop planned for spring 2020 was moved to a virtual format in the fall of 2020. Despite the challenges, setbacks, and restrictions, we were able to maintain field activity, consulting, and pest management surveys and pest management research was conducted. Timely, relevant information continued to be provided via newsletters in the Delaware Weekly Crop Update. We also successfully on boarded a new plant diagnostician (Jill Pollok) and an extension agent focusing on turf management (John Emerson).

2020 Activities


  • Weekly Crop Update – UD’s weekly pest and crop advisory continues to be successful and reaches over 700 unique email addresses. Issues run regularly from April to September;
  • Ornamentals Hotline – weekly newsletter reaching approximately 200 landscapers and other green industry professionals;
  • Delaware Horticulture Industry Expo January 2020
  • Turf Expo November 2020
  • Delaware AgWeek 2020
  • MidAtlantic Crop Management School (virtual 2020)
  • UD Weed Science program (along with other extension programs) continues to expand and refine website on integrated weed management (
  • Spotted Lanternfly trainings via zoom
  • Emerald Ash Borer short course
  • Increasing pollinator friendly plantings in developments
  • Public engagement via Twitter and Instagram of multiple team members

Delaware EIP Extension Implementation Project

  • Field Crops
    • Palmer amaranth management in soybean using narrow rows, harvest technology, cover cropping
    • Cover crop demonstration trials – 6 cooperator locations
    • Recorded weed emergence timing of over 12 common summer annual weed species, part of Hatch project coordinated by Cornell University)
  • Forage – at least two alfalfa fields and one grass hay fields periodically scouted for insect and weed pests.
  • Urban – tree planting demonstration was infested by Emerald Ash Borer.
  • Specialty
    • Weed management and resistance – “overlapping residual herbicides” – crop safety satisfactory when overlapping residuals. Continuing research before making recommendations
    • Insect trapping network and CEW resistance, Bt sentinels, – continuing to maintain insect trapping network, testing CEW resistance to pyrethroids and Bt traits in sweet corn in collaboration with UMD.
    • High tunnels, small fruit and vegetable pest management trials (DSU) – High tunnel pest management demonstrations with DSU.
    • 14 snap bean and 23 lima bean fields were surveyed close to harvest for weeds (part of a collaborative team coordinated by USDA-ARS Champaign-Urbana, IL)


  • 2020 Beginning Farmer Training (partially virtual)
  • Master Gardener core and advanced training; Master gardener led trainings for general public
  • Herbicide Resistance workshops – 5 half-day workshops with MD, VA, and DE (virtual)
  • Expansion of undergraduate/graduate level IPM course for Plant and Soil Sciences Department

Other Current Projects

  • Cucurbit arthropod pest management research - seasonal pattern, resistance monitoring.
  • Nematode and Fungal disease survey of field crops across Maryland and Delaware
  • Disease yield loss estimates in corn, soybean, and wheat
  • Stevia disease demonstration plot
  • Small grains fungicide efficacy trials
  • Merging cereal rye and herbicide: how can we reduce herbicide inputs
  • Exploring the Benefits and Pitfalls of Planting Green
  • Slug and Natural Enemy phenology
  • Managing Ditches for Conservation Biological Control
  • Soybean Prophylactic Insecticide Costs and Benefits
  • 2020 Insect Pest Management trial summaries are available at


Petrovic K., Skaltsas D., Castlebury L., Kontz B., Allen T., Chilvers M., Gregory N., Kelly H., Koehler A., Kleczewski N., Mueller D., Paul P., Price T., Smith D., and Mathew F. 2020. Three novel species of Diaporthe from soybean (Glycine max L.) cause Phomopsis seed decay in the United States. Accepted to Plant Disease.

Mueller D.S., Wise K.A., Sisson A.J., Allen T.W., Bergstrom G.C., Bissonnette K.M., Bosley D.B., Bradley C.A., Byamukama E., Chilvers M.I., Collins A.A., Esker P.D., Faske T.R., Friskop A.J., Hagan A.K., Heiniger R.W., Hollier C.A., Isakeit T., Jackson-Ziems T.A., Jardine D.J., Kelly H.M., Kleczewski N.M., Koehler A.M., Koenning S.R., Malvick D.K., Mehl H.L., Meyer R.F., Paul P.A., Peltier, A.J., Price, T., Robertson, A.E., Roth, G.W., Sikora, E.J., Smith, D.L., Tande, C.A., Telenko, D., Tenuta A.U., Thiessen L.D., and Wiebold W.J. 2020. Corn yield loss estimates due to diseases in the United States and Ontario, Canada from 2016 to 2019. Plant Health Progress. 21:238-247.

Kessler A.C. and Koehler A.M. 2020. First report of Rhizoctonia solani AG 4 causing root and stem rot of stevia in Delaware and Maryland. Plant Disease. 104:3076.

Bickel J.T. and Koehler A.M. 2020. Evaluation of foliar fungicides for management of gray leaf spot of corn in Delaware, 2019. Plant Disease Management Reports. In Press. 14:V132.

Rogers L.W. and Koehler A.M. 2020. Evaluation of foliar fungicides for management of Septoria leaf spot on stevia in Delaware, 2019. Plant Disease Management Reports. 14:V169.

Koehler A.M. 2020. Evaluation of foliar fungicides and application timings for management of wheat diseases in Delaware, 2019. Plant Disease Management Reports. 14:CF006.

Koehler A.M. 2020. Foliar fungicides and application timings for control of wheat diseases in Georgetown, Delaware, 2019. Plant Disease Management Reports. 14:CF005.

G. P. Dively, T. P. Kuhar, S. Taylor, H. B. Doughty, K. Holmstrom, D. Gilrein, B. A. Nault, J. Ingerson-Mahar, J. Whalen, D. Reisig, D. L. Frank, S. J. Fleischer, D. Owens, C. Welty, F. P. F. Reay-Jones, P. Porter, J. L. Smith, J. Saguez, S. Murray, A. Wallingford, H. Byker, B. Jensen, E. Burkness, W. D. Hutchison, and K. A. Hamby. 2020. Sweet Corn Sentinel Monitoring For Lepidopteran Field-Evolved Resistance to Bt Toxins. J Econ Ent doi 10.1093/jee/toaa264. Owens, D., J. Deidesheimer, and C. Stubbs. 2019. Insecticide efficacy against corn earworm in sweet corn, 2019. A.M.T. 45:1, tsaa099.

Owens, D., J. Deidesheimer, and C. Stubbs. 2020. Insecticide efficacy against sugarcane aphid in sorghum, 2019. A. M. T. doi: 10.1093/amt/tsaa092.

Musser, F. R., A. L. Catchot, Jr., S. P. Conley, J. A. Davis, C. DiFonzo, J. K. Greene, G. M. Lorenz, D. Owens, D. D. Reisig, P. Roberts, T. Royer, N. J. Seiter, R. Smith, S. D. Stewart, S. Taylor, K. Tilmon, R. T. Villanueva, and M. O. Way. 2020. 2019 soybean insect losses in the United States. Midsouth Entomol. 13: 1-23.


Coronavirus restrictions at both the state and university level seriously impacted work efficiency, output, and outreach. For example, the significant factor was the extreme limitation of seasonal workforce, which forced many programs to scale back plans or eliminate planned activities entirely.

Increasing pressure to implement some form of cost recovery for the plant diagnostic clinic. Other neighboring states that implemented cost recovery have observed a significant decrease in annual sample submission volume.