Two Spotted Spider Mites and Cyclamen Mites Found in Strawberries.

Emily Zobel on

By Jerry Brust, UME

With the cooler weather we have had of late I was surprised to find low levels of mites in strawberry fields, with a few hot spots of mites in some high tunnels. There were two species of mites found: the two spotted spider mite, Tetranychus urticae and the cyclamen mite Phytonemus pallidus.

Fig. 1 Overwintered female two spotted spider mite.

Overwintering female two spotted spider mites are an orangish-red (Fig. 1) and most of the mites that can be seen with a naked eye will appear reddish in color. Spider mites overwinter in the soil or leaf litter, although they may remain somewhat active in high tunnels through the winter. The light yellowish eggs are pearl-like in appearance and are attached to the undersides of leaves or stems. Feeding damage by mites that occurs before fruiting can cause the most loss in yield, but after the first strawberry harvest plants can tolerate much greater rates of infestation. Growers should check their strawberries for mites now, especially if you have them in a high tunnel. If mites are found now you need more than 5 mites per leaflet (1/3 of a leaf) to justify the expense of a miticide application.

Continue reading Two Spotted Spider Mites and Cyclamen Mites Found in Strawberries.

Bruising on Strawberry Leaves

Emily Zobel on

By Jerry Brust, UME

Over the years I have seen dark spots on the foliage of strawberry plants (Fig.1). These spots can look pretty bad at times and are thought to possibly be the start of some disease such as angular leaf spot or anthracnose. The dark spots are usually on the upper or lower surface of the leaf, but at times can be found on both surfaces of a leaf, which can indicate a biotic source for the problem. These damaged areas of strawberry foliage can be very disconcerting when they appear as dark spots on the stems (Fig 2).

Fig.1) Dark spots on strawberry leaves often mistaken for the start of a foliar disease.

Continue reading Bruising on Strawberry Leaves

Strategies for Effective Management of Botrytis and Anthracnose Fruit Rot in Strawberries

Emily Zobel on

Strategies for Effective Management of Botrytis and Anthracnose Fruit Rot in Strawberries

Dr. Mengjun Hu, Univ. of Maryland, and Kathy Demchak, Penn State Extension

Managing gray mold (Botrytis) on strawberries is increasingly challenging because of fungicide resistance development, plus a new Botrytis species that is less susceptible to fungicides is becoming common in the mid-Atlantic region. Resistance to certain fungicides is also a problem in management of anthracnose fruit rot.  This article describes disease management strategies designed to slow further resistance development, while also providing specifics for managing our two most common fruit rots.

Gray mold on strawberry. Photo: Kathy Demchak, Penn State Extension

First, what’s new with Botrytis.  There are at least 4 species of Botrytis that can infect strawberries, but only two of them have been commonly found in the region. Botrytis cinerea, the species traditionally infecting strawberries, is present nearly everywhere and affects many horticultural crops.  Recently another species, Botrytis fragariae, has also been found and as its name indicates, is more specific to strawberry plants. It appears to overwinter on strawberry plant tissue, and preferentially colonizes blossoms early in the spring, causing them to “turn brown and dry up”.  While sometimes only one of these species is present, both can be present at the same time in a field and even in the same blossom.  Using certain fungicides selects for resistant strains of either species, and also preferentially selects for one species over the other.  This means that both species have resistance to multiple fungicide groups, and both species can survive in fungicide-treated fields.

How can you tell if the newer species of Botrytis might be present in your fields?  While B. cinerea (the traditional species) is often isolated from both flowers and fruit, B. fragariae (the new one) is often isolated from flowers, and it has been shown that B. fragariae infection was much more aggressive on strawberry flowers than fruit. If you see larger-than-usual numbers of blossoms turning brown and shriveling (not to be confused with frost damage, which blackens the center of the flower), it may be prudent to choose fungicides as if B. fragariae presence had been confirmed in your field.  If you see no more symptoms on the flowers or buds than usual, you may be able to assume that the new species isn’t present, or at least not to a great extent.

Continue reading Strategies for Effective Management of Botrytis and Anthracnose Fruit Rot in Strawberries

Apple Scab Alert!

Emily Zobel on
Despite cooler temperatures during the past few days, apple scab (Venturia inaequalis)  spores continue to mature. A significant apple scab infection event is forecasted April 5 to 7, 2022, in Pennsylvania and surrounding area. For those with green tissue present on their apple trees, protection is necessary for this event.
The apple scab fungus overwinters in infected leaves.  As it warms up in the spring they mature and produce spores that are discharged into air currents and carried to developing apple buds. The disease negatively affects fruit size and quality (due to blemishes and poor ripening). Over time, repeated defoliation from the disease reduces tree vigor, growth, and yield. 
Apple scrub leaf lesions.
Photo by Penn State Department of Plant Pathology & Environmental Microbiology Archives , Penn State University, Bugwood.org
Apple scab produces gray-to-olive green lesions on the leaves ( as seen above), but may also be seen on blossoms, sepals, petioles, pedicels, and fruit. On leaves, lesions first appear on the undersides of young leaves in the spring as they unfold and are exposed to infection. Leaves are susceptible to infection for about 5 days after they unfold. Fruit may become infected at any time in its development. Typical fruit lesions are distinct, almost circular, rough-surfaced, olive-green spots up to ¾ inch in diameter. 
Control information can be found on Penn State Extension website:  https://extension.psu.edu/2022-disease-update-apple-scab-infection-event-april-5-7-2022 

Allium leaf miner

Emily Zobel on
Adult allium leaf miners.

Allium leaf miner Phytomyza gymnostoma is a pest on chives, scallions, garlic, onions, and leeks. Overwinter ALM across the Mid-Atlantic will be emerging soon. Start scouting for ovipositor markings made by female ALM over the next few weeks on food and ornamental Allium crops. These markers will be neat rows of white spots descending from the upper tips of allium leaves. These marks will be typically be seen on the tallest leaves first. ALM Larvae mine leaves and moves towards and into bulbs and leaf sheathes. The leaf punctures and mines serve as entry routes for bacterial and fungal pathogens.

Spring crops are usually not as hard-hit as fall crops, especially when looking at leeks, but this pest has steadily increased its geographical range each year and its damage potential. If you had some infestation last year, you will especially want to look for this pest’s signs.

Yellow sticky cards or yellow plastic bowls containing soapy water can be used for monitoring but are not affected control independently. 

 

Onion leaf blades showing round white dots made by female Allium leaf miners. Photo by Jerry Brust

 

Cultural Control: Covering plants in February, prior to the emergence of adults, and keeping plants covered during spring emergence, can be used to exclude the pest. Avoiding the adult oviposition period by delaying planting (after mid-May we think) has also been suggested to reduce infestation rates. Covering fall plantings during the 2nd generation flight can be effective. Growing leeks as far as possible from chives has been suggested. Organic

 

Chemical Control: Azadirachtin (Aza-Direct or other formulations) or spinosad (Entrust or other formulations) follow label instructions for leaf miner.

Synthetic Chemical Control: Systemic and contact insecticides can be effective. EPA registrations vary, however, among Allium crops. Check labels to ensure the crop is listed, and for rates and days-to-harvest intervals. Options that may be effective include cyromazine (Triguard), dinotefuran (Scorpion), spinetoram (Radiant), lambda-cyhalothrin (Warrior II or other formulations), and abamectin (Agri-Mek or other formulations).

Farm Stress Management Workshops

Emily Zobel on

University of Maryland Extension will host a series of Farm Stress Management  Workshops for Agriculture Service Providers. 

This workshop is designed for Agriculture Service Providers to equip them with the skills and  knowledge to support farms and farm families in times of distress. The University of Maryland  Extension Farm Stress Management Team will train service providers to identify signs of  distress, develop skills to communicate with those experiencing stress, and provide resources  both locally and nationally. Financial and regulatory topics will also be discussed as they are  often contributors to stress on the farm. 

Upcoming Trainings (All hosted from 9:30 AM – 2:30 PM): 

  • Southern MD (UMD Extension, Calvert County) : April 5, 2022. 30 Duke Street, #103, Prince Frederick, MD 20678
  • Lower Shore (University of Maryland Eastern Shore) : April 6, 2022. Hensen Center – 11868 Academic Oval, Princess Anne, MD 21853
  • Central MD (UMD Extension, Montgomery County) : April 7, 2022. 18410 Muncaster Rd, Derwood, MD 20855
  • Western MD (UMD Extension, Washington County) : April 13, 2022. 7303 Sharpsburg Pike, Boonsboro, MD 21713
  • MidShore (Chesapeake College) : April 14, 2022. Higher Education Center – 1000 College Circle Wye Mills, MD 21679

For more information contact Shannon Dill, Extension Educator, University of Maryland  Extension (410-822-1244 / sdill@umd.edu). To register visit  

https://fsagservice2022.eventbrite.com. The program is open to all. If you need special  accommodations please contact the organizers two weeks prior to the event. For more  information on the Farm Stress Management Education Project visit  

www.go.umd.edu/farmfamily.  

This material is based upon work supported by the National Institute of Food and Agriculture,  U.S. Department of Agriculture, through the Northeast Sustainable Agriculture Research and  Education program under sub award number ENE20-160-34268.

Mowing: a casually thought of integrated weed management tool

Emily Zobel on

By Cerruti R2 Hooks$ and Dwayne Joseph*
$Professor and Extension Specialist, *Post-Doctoral Fellow, CMNS, Department of Entomology,

Mowing is a relatively inexpensive form of mechanical weed control that can reduce the use of tillage, herbicide and manual weeding. It may serve as an alternative to herbicide and cultivation or part of an integrated approach. However, mowing to manage weeds has not been well studied compared to other IWM tools and is more popular in habitats with perennial stands of vegetation. Consequently, limited information is available on mowing use in crops. As such, it is not adaptable to numerous cropping systems; and partially for this reason, it is used mainly for aesthetic reasons and preventing seed production in perennial stands of vegetation neighboring cropland. Still, research has shown that mowing can be used jointly with other weed management tools such as applying herbicides, cover cropping and growing competitive crops. Mowing may also be used to successfully manage perennial weeds by removing the aboveground plant parts and consequently reducing food reserves in their storage organs. This, however, may take multiple years and the integration of other weed management tactics. Some research has found that combining mowing with herbicides enhances perennial weed control. Still, there are advantages and disadvantages of using mowing as a weed management tool. Mowing generally does not have any negative environmental effects. However, many weeds especially those that grow close to the ground such as buckhorn plantain are naturally tolerant of mowing. As with any IWM program, it is important to “keep weeds guessing” by utilizing different management tactics; and mowing is no exception to this rule. For example, repeated use of mowing as a single weed management tactic may result in a selection pressure or shift to weed species or genotypes that can reproduce even if repeatedly mowed. These species may overtime become more difficult to manage. As such, in those situations where mowing is practical, one should consider making it part of an overall IWM program.  Financial support for the publication of this article is via USDA NIFA EIPM grant award numbers 2021-70006-35384 and NESARE – Research for Novel Approaches (LNE20-406R).

Click here to download the full article  

Maryland Beginning Farmer Success Course

Emily Zobel on
urban farm with lettuce and other greens growing

Maryland Beginning Farmer Success Course  

This course is designed for those who are considering or  in the beginning stages of starting a farm as a business.  Topic covered will include: Business planning, marketing, crop production, soil health, pest management, food safety and regulations and certification. Classes will meet virtual Thursday evening from 7pm to 8:30pm, from February 10 through April 2, 2022.  Cost $65.

More information can be found at https://go.umd.edu/bfs2022 

University programs, activities, and facilities are available to all without regard to race, color, sex, gender identity or expression, sexual orientation, marital status, age, national origin, political affiliation, physical or mental disability, religion, protected veteran status, genetic information, personal appearance, or any other legally protected class.

 

Upcoming UME Fruit and Vegetable Meetings!

Emily Zobel on

Below is a list of UME Fruit and Vegetable meetings for 2022!

Virtual Statewide Grower Meeting

The following meeting will be in-person. Participants may be required to wear a mask and follow social distancing guidelines based on county guideline at the time of the meeting. Seating may be limited for on-site participation due to University of Maryland COVID 19 meeting rule compliance. 

  • Central Maryland Vegetable Growers Meeting
    January 27, 2022,  8:00 a.m. to 1:00 p.m.
    Location: Friendly Farm Inn, (17434 Foreston Road) Upperco, Maryland.
    Topics will include: Blueberry Fertility, Strawberry Disease Management, Apple Rootstocks, Management of Spider Mite and Thrips, MDA updates ….and more!
    Presentations start at 8:30 and end at 12:30 with Friendly Farms famous all-you-can-eat lunch. Cost to attend this meeting is $28.00 if you pre-register or $35.00 at the door. 
    For more information or to register call UM Extension Baltimore County Office at 410-887-8090 or email Erica Crowl ecrowl@umd.edu.  Register online: https://2022veggieday.eventbrite.com 
  • Southern Maryland Vegetable & Fruit Production Meeting
    February 10, 2022, 8:00 a.m. to 4:00 p.m.
    Location: Baden Volunteer Fire Department, 16608 Brandywine Road, Brandywine, MD 20613
     $15.00 fee payable at the door. Speakers will provide IPM updates and present on a broad range of production topics.  For more information please contact Ben Beale (301-475-4484)  or Dave Myers (301-405-4351). Register here
  • Western Maryland Fruit Meeting
    February 10, 2022, 9:00 a.m. to 4:00 p.m.
    Location: Western Maryland Research and Education Center, 18330 Keedysville Road, Keedysville, MD.  Fee of $30.00  (after Feb. 3 – $40) Speakers will provide IPM  & Nutrient Management updates and will present on Fruit production topics. For more information please contact Joe Fiola (30-432-2767 x 344). Register Here 
  • Eastern Shore Vegetable Growers Meeting
    February 16, 2022, 8:00 a.m. to 1:00 p.m.
    Location: Cambridge Premier Cinemas, 2759 Dorchester Square, Cambridge, MD.
    Cost $10.  For more information please contact Emily Zobel (401-228-8800).