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Powerpoint (in pdf form) talk by Nancy Gregory in the Processing Vegetables Session of Delaware Ag Week, January 10, 2018. The pictures may be very helpful : Gregory-P-capsici-Ag-Week-Veg-January-2018

Phytophthora capsici on snap bean

If you have any questions, please contact ngregory@udel.edu
1/16/2018 NFG
 

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For those potato farmers placing orders for seed potatoes soon, consider the Plant and Pest Advisory put out by Andy Wyenandt at Rutgers: http://plant-pest-advisory.rutgers.edu/best-management-practices-for-managing-dickeya-dianthicola-in-potato/
If you suspect bacterial infection in seed potatoes when received, cut or at planting, contact your County Extension Office.
NFG 1/12/2018                Image, N Gregory

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Climate Risk: From Assessment to Action - Sponsored by Climate Action in Financial Institutions.   The event will provide public and private financial institutions with an opportunity to learn from each other, exchange lessons learned and best practices, and identify opportunities for collaboration.
Download tentative agenda
Climate Risk: From Assessment to Action
Tuesday, February 13, 2018
Inter American Development Bank
1330 New York Ave. N.W.
Washington, DC 205777

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Join the Extension Disaster Education Network (EDEN) for a webinar on January 10th.
Wednesday, January 10, 2018 starting at 2:00 pm EST/1:00 CST/12:00 MST/11:00 PST for a webinar on the Communicating About Risks – It’s More than Just Information
This webinar discusses: Basic social science behind why we respond to risks the way we do. Ways to improve how we communicate about long-term risks
Presenter: Sarah Watson is the Coastal Climate and Resilience Specialist at S.C. Sea Grant Consortium and the Carolinas Integrated Sciences and Assessments.
To Register: https://extension.zoom.us/webinar/register/WN_ePK6EwbnSTi2_6Tbit9xmg
NFG 1/9/2018

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The spotted lanternfly is a non-native plant hopper originally from Asia.

(Photos: PA Dept of Agriculture)

Lycorma deliculata is small, brightly colored, but very destructive. It was found in Pennsylvania in 2014-15 and has spread slowly, to be found in New Castle County, DE in late 2017. The adult is approx 1 inch by 1/2 inch at rest, and grey/pink in color. Expanded hind wings are a colorful red with black spots and the abdomen yellow. The insect feeds by producing wounds along branches, that exude sap. Hosts include grapes, apples, stone fruits, walnut, willow, and tree of heaven, which officials think is a necessary host for reproduction. Egg  masses are laid in November, and look like smears of old chewing gum on branches, rocks, tree trunks, railway boards, cinder blocks, outdoor furniture and vehicles. Eggs will hatch in April or May, and nymphs are red and black.  If you find this bug or egg masses, take a picture and contact de.gov/hitchhikerbug  More info may be found at: https://dda.delaware.gov/plantind/spotted-lanternfly.shtml .
NFG 12/14/2017

This season, many people are shopping for a perfect cut tree or live tree to decorate their homes.
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This season, many people are shopping for a perfect cut tree or live tree to Douglas fir treesdecorate their homes. Our local Christmas tree growers face many challenges to growing a perfect tree, an expensive and time-consuming process. A Christmas tree takes 8 to 10 years to grow to a good size, and there are many hurdles along the way. Trees must be planted properly in good soil, not too shallow or not too deep. It may take up to three years for a transplanted seedling to establish a good root system.
Insect pests and plant diseases can cause problems for Christmas tree growers. Phytophthora root rot is problematic on tree farms in many states. Phytophthora is a fungus-like organism, favored by wet, saturated soils with poor drainage. Roots in saturated soil may be stressed. The best management strategies for root rot are the purchase of clean healthy seedlings and proper site selection, because the best possible control is to avoid Phytophthora root rot to start.
There are other pests and diseases that attack Christmas tree species, such as needlecast fungi that cause spotting and discoloration of needles, and needle drop. Growers must scout their trees, apply fertilizer and pest control, trim to shape, and keep up with research on tree species and new varieties. Sales of trees, following the 10 years of nurturing, all occur yearly within a 4 to 6 week period! Our Christmas tree growers are dedicated agricultural professionals who love to see smiles on the faces of people who purchase and enjoy the trees that they grow!
Find a Delaware Christmas Tree Grower near you at: http://www.delawarechristmastreegrowersassn.com/
NFG 12/5/2016

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Fusarium wilt caused by the fungus Fusarium oxysporum f.sp. chrysanthemi is a vascular

wilt disease of chrysanthemum, and one I worked on for my Master's thesis. The fungus is soil-borne or spread through vegetative cuttings, and invades the stem. The fungus plugs water conducting tissue (xylem) with mycelium and spores. Fusarium wilt symptoms are often confused with root rot but plants infected with Fusarium may show wilt only on one side and roots often appear healthy. Early symptoms of Fusarium wilt are wilting leaves on one side of the plant followed by yellowing and browning of the leaves. Infected plants are stunted, fail to produce flowers, and vascular browning can be seen on cut stems. Symptom development is favored by temperatures above 24 C (75 F) and high humidity. Although specific to chrysanthemum, the fungus can survive in soil or debris for years and is difficult to control if established in a field or bed.


Managing Fusarium wilt includes use of disease-free (culture-indexed) cuttings and pathogen-free media and materials. Avoid highly susceptible cultivars such as 'Bravo', 'Cirbronze', 'Illini Trophy', 'Orange Bowl', 'Royal Trophy', Allegra and 'Yellow Delaware'. Other management practices include maintaining soil pH between 6.5 and 7.0, utilizing the nitrate form of nitrogen in fertilizers and drenching with fungicides. Effective fungicides include azoxystrobin (Heritage), pyraclostrobin plus boscalid (Pageant) and Trichoderma harzianum (PlantShield). Fungicides containing thiophanate methyl (Cleary's 3336) and fludioxonil (Medallion) have been reported to suppress Fusarium.
In studies at the Long Island Horticultural Research and Extension Center, Cornell University, yellow-flowered mums were evaluated for susceptibility to Fusarium wilt. Wilt developed three weeks after inoculation in ‘Allegra’ (susceptible check), and the cultivars ‘Conaco’, ‘Florina’, ‘Elena’, ‘Malmo’ and ‘Golden Helga’ developed wilt. Symptoms did not develop and the fungus was not re-isolated from cultivars ‘Bernadette’, ‘Bethany’, ‘Diana’, ‘Mary’, ‘Mildred’, ‘Mouria’, ‘Novare’, ‘Castor’ or ‘Sundance’.
NFG, 10/2017

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BACTERIAL LEAF SCORCH (BLS) of hardwood trees, shrubs, and herbaceous plants, is caused by the bacterium, Xylella fastidiosa, carried by small insects such as leaf hoppers and sharpshooters. BLS has been very damaging to red oaks in Delaware and the Mid-Atlantic states for over 15 years. Northern red oak and pin oaks under environmental stress are most susceptible. Symptoms include marginal discoloration or scorch of leaves in late summer or early fall, often with a yellow or dark band on the inside edge of the discolored area. Symptoms are similar to those caused by drought or root issues that interfere with flow of water and nutrients. Plants may not develop symptoms for a year or two after infection, but then thinning of branches occurs and trees die within 5 to 8 years.  Infection is confirmed with a lab test for a fee; please arrange to have samples tested by contacting the UDBLS Red Oak 2016 Plant Diagnostic Clinic. There is a $20 fee for BLS testing. To manage, maintain good tree vigor, and remove infected trees. A UD fact sheet has more info: http://extension.udel.edu/factsheets/bacterial-leaf-scorch/
NFG 9/1/2017

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This summer I had the opportunity to intern in the Plant Diagnostic Clinic through University of Delaware Cooperative Extension. It has given me the opportunity to provide plant health information to the local community in several different ways. My work involved recording the plant samples that were received through the clinic and using different investigative laboratory techniques to determine the cause of decline.  I also worked closely with the USDA to learn more about the fungal pathogen that causes downy mildew on sunflowers, where the goal was to acquire information that could be communicated to growers. Plant health knowledge was also provided to Master Gardeners and landscape professionals through pest walks and workshops. Participants that attended were able to see examples of plant diseases and disorders, both in the laboratory and in the landscape, in hopes that they will implement proper management practices or improve their current practices. The ultimate goal of the Plant Diagnostic Clinic is to understand different plant diseases and share management options with homeowners, landscapers and growers through Extension outreach.
2017 Cooperative Extension Scholar, Jen - 8/29/2017