UME May Vegetable & Fruit Newsletter and Sweet Corn Needs Assessment Survey

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The May issues of the UME Vegetable & Fruit Newsletter is now available.
You can download it and past issues here: https://extension.umd.edu/locations/anne-arundel-county/agriculture-food-systems. 

This issue has information about:
– June Vegetable insect scouting Tips
– Leafminers on Spinach, beets and Swiss Chard
– Edema Problem in Greenhouse Tomatoes
– Two Spotted Spider Mites in Strawberries
– Efficacy of Common Active Ingredients in Organic Insecticides
– How to Disinfect Stakes
– Blueberry IPM
– Primocane Blackberries
– Spotted Wing Drosophila Updated Insecticide Efficacy Chart
and more.

If you grow sweet corn please consider filling out the Corn Earworm Management in Sweet Corn Needs Assessment Survey.

Dr. Kelly Hamby, Associate Professor/Extension Specialist with the Department of Entomology at University of Maryland is leading a team of researchers who have developed a survey to prioritize research and extension efforts for improving corn earworm management in sweet corn throughout the Northeast. We appreciate your participation in this survey and will use results to develop a grant proposal to try to get federal funding to address these needs.

Survey link: https://ume.qualtrics.com/jfe/form/SV_9vRh1xHnDp4KEaa

Farming for Healthy Soils Program

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ANNAPOLIS, MD (April 26, 2021) – The Maryland Department of Agriculture (MDA) is now accepting applications for farmers interested in enrolling their fields in the Farming for Healthy Soils program. Participating farmers will receive free technical assistance and financial incentives to help install the following soil health practices:

  • Conservation tillage;
  • Multi-species cover crops;
  • Extended season cover crops;
  • Prescribed grazing; and
  • Precision nutrient management.

Cost-share funding of $10 to $55 per acre is available to help farmers adopt these key practices. Free technical assistance will be provided by local soil conservation districts or University of Maryland Extension, and will include field evaluations to measure changes in soil health. Financial assistance will also be offered for soils data sampling.

Maryland’s Farming for Healthy Soils program is funded by a three-year, $1 million grant awarded by the Chesapeake Bay Stewardship Fund. In its second year, the grant promotes the use of on-farm soil health practices that increase carbon sequestration, improve soil productivity, and protect water quality in the Chesapeake Bay watershed.

The Chesapeake Bay Stewardship Fund is a partnership between the National Fish and Wildlife Foundation and the U.S. Environmental Protection Agency’s Innovative Nutrient and Sediment Reduction Grants Program and the Small Watershed Grants Program. Additional support is provided by the U.S. Department of Agriculture’s Natural Resources Conservation Service, the U.S. Forest Service, the U.S. Fish and Wildlife Service, and the Altria Group Restoring America’s Resources partnership.

Farmers who want to enroll study fields in this program should contact MDA’s Healthy Soils Program Coordinator Kevin Antoszewski at kevin.antoszewski@maryland.gov. For more information about Maryland’s Farming for Healthy Soils program, please visit MDA’s website.

Asparagus Beetle IPM

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There are two beetle pests that feed on asparagus, the common or striped asparagus beetle (Crioceris asparagi) and the spotted asparagus beetle (Crioceris duodecimpunctata). Feeding on the spears results in scarring, browning, and hooked tips render the crop unmarketable. While both beetles can damage the emerging spears, the common asparagus beetle larvae and adults will also feed on the ferns, which can reduce the plant’s ability to build resources for a strong crop the following spring.

 

Fig 1. Adult Asparagus Beetle Photo by Clemson University – USDA Cooperative Extension Slide Series, Bugwood.org
Fig 2. Adult spotted asparagus beetle.
Photo by Whitney Cranshaw, Colorado State University, Bugwood.org

Adults: Adult beetles are about ⅓ inch in length. The adult common asparagus beetle is blue-blackish with six cream-colored square-shaped spots on its back (Fig 1). Adult spotted asparagus beetles are reddish-orange with twelve black spots on their back (Fig 2). Both the beetles overwinter as adults.

Fig 3. Asparagus Beetle Eggs. Photo by Ward Upham, Kansas State University, Bugwood.org

Eggs: Eggs take about a week to hatch. They are small, cylindrical, and dark-colored. The asparagus beetle lays eggs on the spear at a 90-degree angle in rows of 3 to 8 eggs (Fig 3.), while the spotted asparagus beetle oviposits eggs singularly on the fern.

 

Common Asparagus Beetle Larvae.
Fig 4. Common Asparagus Beetle Larvae. Photo by Clemson University – USDA Cooperative Extension Slide Series , Bugwood.org

Larvae: The larvae of both species are light gray with visible heads and legs. The common asparagus beetle larvae have blackheads (Fig 4.), while the spotted asparagus beetle larvae have an orange head. Larval feeding lasts for 10-14 days. Asparagus beetle larvae feed on the spear, while spotted asparagus beetles will burrow into the berry. Mature larvae crawl to the ground and burrow within the soil to pupate.

Scouting: Scouting should start at the end of April – early May or just after asparagus plants emerge and continue for the rest of the growing season. Check 10 plants in 5-10 different locations in a field, best on a warm, sunny afternoon when beetles will be most active. Treatment may be justified if 10% of spears are infested with beetles or 1-2% have eggs. 

Cultural Controls & Prevention:

  • During harvest, harvest all spears every day to reduce the number of stems where eggs will survive for long enough to hatch.
  • Allow plants in one area to develop ferns so as to act as a trap crop. These plants can then be sprayed selectively.
  • Maintain a clean environment in asparagus fields in the fall to force adults to overwinter in field edges where natural predators reside. 
  • Destruction of crop residues will eliminate overwintering sites for asparagus beetles.  
  • The most important natural enemy of the common asparagus beetle is a tiny parasitic wasp (Tetrastichus asparagi) that attacks the egg stage. These parasitoids lay their own eggs inside the beetle eggs. The immature wasps grow inside the beetle larvae, killing them when they pupate. Studies have found >50% of eggs were killed by parasitoid feeding, and half of the surviving larvae were parasitized. Providing a nearby nectar source such as umbelliferous flowers may enhance wasp populations.

Chemical Control 

  • Organic options on spears include Surround WP as a repellent, EC5.0, or products containing capsaicin (check for certification status).
  • If possible, spot spray along edges of planting where overwintering adults colonize the field and/or band insecticide over the row to help spare natural enemies. Use selective insecticides on ferns.
  • Daily harvest of asparagus makes chemical treatment difficult. 1 dh products are available and can be used immediately after picking to allow harvest the following day (see the Mid-Atlantic Commercial Vegetable Production Recommendations for current recommendations)

 

E. Zobel

Still Time to Find and Remove Spotted Lanternfly Egg Masses

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Doris Behnke, Senior Agriculture Agent Associate | dbehnke@umd.edu
University of Maryland Extension, Cecil County

The spotted lanternfly (Lycorma delicatula) is a invasive planthopper which is native to China, India, and Vietnam. It was detected in Pennsylvania in 2014, and has since been found to have confirmed populations in Delaware, Maryland, New Jersey,  and Virginia.  It has a broad host range including fruit, ornamental and woody plants.

Nymphs will begin hatching out in May so now is the time to remove the egg masses that the adult spotted lantern fly (SLF) laid last year. To do this you will need some hand sanitizer, a plastic bag, and a firm card for scraping.

  1. Squirt the hand sanitizer into the plastic bag.
  2. Arrange the opened bag just below the SLF egg mass.
  3. Apply a firm amount of pressure on the edge of the card and scrape the card down and across the egg mass.
  4. Catch the eggs in the bag, then squish the hand sanitizer and eggs around in the bag.
  5. Seal the bag and then dispose. Help stop the spread of SLF

For more information please visited the MDA website: https://mda.maryland.gov/plants-pests/Pages/spotted-lantern-fly.aspx 

USDA Invests More Than 169.9 Million in Specialty Crops Grants

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The U.S. Department of Agriculture (USDA) Agricultural Marketing Service (AMS) is announcing $169.9 million for the Specialty Crop Block Grant Program (SCBGP) to fund innovative projects designed to support the expanding specialty crop food sector and explore new market opportunities for U.S. food and agricultural products. The purpose of the Specialty Crop Block Grant Program (SCBGP) is to enhance the competitiveness of specialty crops. Specialty crops are defined as “fruits, vegetables, tree nuts, dried fruits, horticulture, and nursery crops (including floriculture).”
The total includes:
  • $72.9 million available as part of the annual Farm Bill funding for the program; and
  • An additional $97 million available as emergency funding for applications under this solicitation. Congress provided this funding in the Consolidated Appropriations Act, 2021, due to COVID-19 impacts to the food system.

Grant project funding awarded as part of pandemic assistance can also go to organizations to assist farmworkers (e.g., for PPE and vaccination costs), projects to fund farmers, food businesses, and other relevant entities to respond to risks and supply chain disruption.

For more information about grant eligibility, visit the SCBGP website.

Maryland Department of Ag SCBGP website

The SCBGP funds are allocated to U.S. states and territories based on a formula that considers both specialty crop acreage and production value. Interested applicants should apply directly through their state departments of agriculture.  Applications must be submitted electronically by 11:59 p.m. Eastern Time on June 11, 2021. 

Source: https://www.ams.usda.gov/press-release/usda-invests-more-330-million-specialty-crops-grants-incentives-purchase-fruits-and

Emily Zobel, 

Allium (Onion) Leafminer

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Allium leafminer (ALM), Phytomyza gymnostoma (Diptera: Agromyzidae), is an invasive leaf-mining fly from Poland that was first detected in Pennsylvania in 2015. They overwinter as pupae in plant tissue or surrounding soil. Adults emerge mid-March throughout April (250°Degree Days with a minimum temperature threshold of 3.5°C.). The adults are small (~ 3 mm) long grey or black flies with a distinctive yellow or orange area on the top and front of head and legs have distinctive yellow “knees” (Fig.1, Fig 2). The larvae are white maggots, headless, and around ~ 8 mm long at their final instar.  The pupa are dark brown, ~3.5 mm long.

Adult allium leafminer
Figure 1. Adult allium leafminers. Photo by Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org
Figure 1. Allium leafminer on scallion leaf.
Figure 2. Allium leafminer on scallion leaf. Photo: Brandon Lingbeek, Penn State

 Adults will mate lay eggs inside the leaves of Allium species, creating a row of several small round white dots (made by the female’s ovipositor) on the top half of the leaf blades (Fig.3). Larvae mine leaves and move towards and into bulbs and leaf sheathes. Damage from Allium leafminer can also cause the plant to exhibit curly, wavy or distorted leaves. Both the leaf punctures and mines serve as entry routes for bacterial and fungal pathogens. The larvae may move into the soil to pupate. These pupae undergo a diapause period which lasts throughout the summer, and will emerge as adults in the autumn (September / October). 

Allium leafminer
Figure 3. Oviposition and feeding damage by Allium leafminer. Photo by Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org

 While spring crops are usually not as hard hit as fall crops, this pest has been steadily increasing its geographical range each year and its damage potential. Fields that had pressure last year should be scouted for feeding damage this year.  Yellow sticky cards or yellow plastic bowls containing soapy water can be used for monitoring this pest. You can reduce infestation rates by rotating fields, growing leeks as far as possible from chives, and delaying the planting of spring allium crops. Growing allium crops on reflective mulch has reduced the severity of allium leafminer damage in research trials in New York. Placing row covers over allium crops during the period flies and keeping plants covered during the 3-4 weeks of emergence will exclude the pest. Larvae and pupa tend to be found in the outermost layers of leaves from leek and scallion, so the hand removal of these layer will often create a blemish-free product.

Several systemic and contact insecticides are approved for this pest, but EPA registrations vary among Allium crops. When using chemical control, check labels to ensure the crop is listed and for rates and days-to-harvest intervals. Always read and follow the label. The label is the Law.  

 For chemical recommendations, see the 2020-2021 Mid-Atlantic Commercial Vegetable Production Recommendation Guide: https://extension.umd.edu/mdvegetables/2020-2021-mid-atlantic-commercial-vegetable-production/commodity-recommendations 

 Azadirachtin (Aza-Direct or other formulations) or spinosad (Entrust or other formulations) are options for organic chemical control.

Thrips in Greenhouse and High Tunnels.

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By Jerry Brust, IPM Vegetable Specialist, University of Maryland; jbrust@umd.edu 
and Karen Rane, Plant Diagnostician, University of Maryland rane@umd.edu

Over the past few weeks we have seen several greenhouse (GH) and high tunnel (HT) vegetable (basil and tomato mostly, but also lettuce, pepper and spinach) operations from around Maryland having problems with thrips. There are several species of vegetable thrips with the most common being the Eastern flower thrips, Frankliniella tritici, Tobacco thrips Frankliniella fusca, Western flower thrips, F. occidentalis and Onion thrips Thrips tabaci.

The last three species are the ones most likely to transmit tomato spotted wilt virus (TSWV). Thrips are tiny, thin yellowish-orange insects the size of metal filings with fringed wings. Thrips have several generations (up to eight) a year. When the weather is warm, the life cycle may be as short as 2 weeks.  They feed by puncturing the outer layer of plant tissue and sucking out the cell contents, which results in stippling or discolored flecking that is usually accompanied by black flecks of frass on the damaged areas of the leaf surface.


Thrips feeding damage to basil (A) with flecks of black feces associated with feeding scars (B). 

Pepper plant with thrips feeding (A) and TSWV symptoms (B).

Sanitation is one of the most important things that can be done to reduce or eliminate thrips and mite problems from a GH or HT before planting. In most of the cases where we found thrips problems, growers did not follow good sanitation practices. They allowed weeds such as prickly lettuce, chickweed, spiny amaranth, lambsquarters, black nightshade and shepherd’s purse to overwinter in their GH or HT. These weed species not only act as hosts for thrips they also can act as hosts for TSWV. In addition to weeds some growers kept bedding plants in their greenhouse before and at the same time as their vegetable transplants, bedding plants are notorious for harboring thrips.  This allows thrips to overwinter and get a head start on the new plantings. Never grow vegetable transplants in the same greenhouse with bedding plants.

Lettuce leaf with thrips feeding (A) notice how the black flecks follow the feeding scars on the leaf and TSWV symptoms on tomato leaves (B).

Besides the physical damage to leaf and plant tissue several of the thrips can transmit TSWV (Western flower thrips are good at it while Onion thrips and Tobacco thrips are not quite as good at it and Eastern flower thrips cannot transmit the virus). Tomato spotted wilt virus is an obligate parasite, e.g., it must have a living host and must be moved from one plant to another by thrips or through cuttings or possibly seed. This disease can affect tomato and other Solanaceae crops as well as lettuce, beans, cucumber and 170 other plant species. TSWV may occur in the field but tends to affect greenhouse and high tunnel crops more severely. It may take 2 – 4 weeks from when adult thrips first fed on a plant to see initial symptoms occur. Because of this TSWV appears to spread and worsen in plantings over time. TSWV infected leaves may show deformities and mottling or reddish-brown spots or streaks on leaves or stems. Growing tips are usually affected with systemic necrosis and potentially stunted growth.

We tested for both impatiens necrotic spot virus (INSV) and TSWV on tomatoes and bedding plants. Only TSWV was found in both, no INSV was found in any sample. A few growers had some TSWV resistant (or tolerant) tomato varieties (BHN 444 and 640, Dixie Red and Primo Red) and those plants showed no symptoms. However, research shows that the flowers of resistant plants may NOT be resistant, so plants could possibly still become infected with TSWV if thrips feed on the flowers. Several high tunnel vegetable growing operations as well as some GH operations we have seen or that have been reported to us have 20-30% of their plants showing signs of TSWV infection. These plants will not produce much of anything in the way of a harvest and will need to be removed and replaced.

Growers can monitor for thrips using yellow sticky cards that are placed at the same height as the vegetable plants and checking them 2-3 times a week. Early detection can mean using horticultural oils or biological controls for thrips management rather than relying on synthetic chemicals. The biological control agents work best in greenhouse situations and have had mixed results in high tunnel conditions. Predatory mites such as Amblyseius cucumeris or A. swirskii are two good thrips predators. A swirskii works better in warmer temperatures (77-85o F) while A. cucumeris is better in cooler temperatures. A. cucumeris feeds only on first instar larvae so must be released early before thrips populations increase. Orius insidiosus the insidious flower bug, is best used on crops that are producing pollen or by releasing the bugs onto flowering ornamental pepper plants that are in flower which serve as banker plants. Beauveria bassiana, an entomopathogenic fungus that attacks thrips can control thrips problems before they get started by applying weekly applications very early on in the crop cycle in the GH or HT. However, once thrips populations start to rapidly increase a recommended chemical for GH or HT use on the particular vegetable crop should be used. Be sure you know how your state regulates pesticide use in greenhouses and high tunnels. It should be noted that transmission of TSWV may have already taken place by the time even an effective pesticide is used if TSWV infected weeds or plants are present. The 2020-2021 Mid-Atlantic Commercial Vegetable Production Recommendation Guide has recommendations for both GH and HT management of thrips that might vector TSWV.

 

Harmonized GAP Videos

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The Plant Science Food Safety Group has upload a series of video about Harmonized GAP certification on their YouTube channel found here: https://www.youtube.com/channel/UCGIApo2366cds7uWGr6v2Bg

The first video Introduction to HGAP Audits, will  compares MDA GAP to the Harmonized GAP standard. It gives insights on which of the standards are most frequently missed during an audit and the fees associated with an HGAP audit.

The second recording is on writing a risk assessment for harmonized GAP.  The harmonized GAP standard may require as many as seven risk assessments, depending on the farm practices including: land use history and adjacent land use, water systems, animal activity, soil amendments, pre-harvest, allergens, and produce washing. These assessments begin by identifying the hazards, including the actions taken to prevent the hazards and the monitoring of those actions. Written risk assessments must be reviewed annually or sooner if there are changes in the farm practices or land use.
The new Harmonized GAP standards and checklist can be found here: https://www.ams.usda.gov/services/auditing/gap-ghp/harmonized. As there are many changes in the 2021 standard, farms operating under an existing HGAP plan will need to upgrade their plans before their audit this year. The new standards take effect on May 1st, 2021

2020 Local Food Marketing Practices Survey

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WASHINGTON, Feb. 23, 2021 – Farmers and ranchers still have time to respond to their 2020 Local Food Marketing Practices Survey, according to the U.S. Department of Agriculture’s (USDA) National Agricultural Statistics Service (NASS). NASS will continue to accept responses through April to ensure an accurate picture of U.S. local and regional food systems.

“The Local Food Marketing Practices Survey is conducted in support of the growing demand for local and regional food systems,” said NASS Administrator Hubert Hamer. “The data are vital to understanding the many benefits of this sector. They will inform industry decisions and assist producers, researchers, policymakers, USDA officials, and more. NASS is committed to giving producers every opportunity to be counted in this special study.”

The 2020 Local Food Marketing Practices Survey is part of the Census of Agriculture program and as such is required by federal law. These federal laws require producers to respond and USDA to keep identities and answers confidential. Over the next several weeks, NASS will follow-up with additional mailings and phone calls to farmers and ranchers who have not yet responded. Producers are encouraged to complete their questionnaire online at www.agcounts.usda.gov, by mail, or phone as soon as possible. All information collected will be used for statistical purposes only and published on the NASS website in aggregate form this November.

To learn more about NASS and the Local Foods Marketing Practices Survey, visit www.nass.usda.gov/go/local-food. If you have questions or difficulty completing your survey, please call toll-free 888-424-7828.