Vegetable Notes 2025 Vol. 37:2

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Pest Alerts

Algae in transplants: Onions and leeks are some of the earliest crops to be seeded in the greenhouse, in the first few weeks of March. Every year we get calls about poor stands and green growth or crust forming on soil in transplant trays. The green growth is algae, which can grow on any greenhouse surface and comes in on dust or in irrigation water. Algae thrives in sunny, wet areas with high organic matter, e.g. an overwatered tray full of potting media, especially if the media is compost-based or contains a lot of peat. Algae do not harm plants directly, but can slow gas exchange through media, thereby slowing root growth. Algae also attracts fungus gnats and shore flies, which not only feed on algae and other fungal growth in the growing medium, but also on plant roots, creating wounds where pathogens might gain entry into plant roots. Once you have algae, it is hard to get rid of, so how can you prevent algae from growing?

Pre-season cleaning and managing moisture are key in preventing algae in greenhouses. Algae doesn’t need potting soil to grow in a greenhouse—it can grow on any moist surface—so thoroughly cleaning and sanitizing your greenhouse benches, floors, trays, and any other surfaces in your greenhouse can help reduce algal “inoculum”. Several algicides are currently registered for greenhouse use. Disinfectants can be used as part of pre-crop cleanup program and during the cropping cycle for routine algae management. Quaternary ammonium materials (e.g. Green-Shield, Physan 20, Triathlon can be applied to floors, walls, benches, tools, pots, and flats as disinfectants. Hydrogen dioxide (e.g. ZeroTol), is a sanitizer also labeled for use on greenhouse surfaces. Read and follow directions on these products.

Manage moisture and make sure that your transplants are able to quickly take up all the water you apply when irrigating. Avoid overwatering, especially on cloudy days. Leeks and onions start out so small that if they are planted in a large cell, their roots can’t access all the water, the soil stays wet, and algae begins to grow. Leeks and onions don’t need big cells (you can use as small as 288-celled trays!) and they should transplant out well since they have big root systems. You can also achieve faster drying of soil by using lighter media and/or mixing in extra perlite to improve drainage.

Glandular trichomes in spinach: We have received some questions about tiny, translucent spheres on spinach leaves—these are glandular trichomes, or sphere-shaped hair-like outgrowths that form on the leaf surfaces. They are often mistaken for insect eggs, aphids, or mites. They are not harmful, but some growers or customers may find them unattractive. Many types of plants produce trichomes on their leaves, of all shapes and sizes—trichomes are what make eggplant and tomato leaves fuzzy, and the chemicals in stinging nettle trichomes make our skin itch and burn. The most common function of trichomes is to protect plants from insect feeding and egg-laying—their physical presence can make it difficult for insects to reach leaf surfaces, and some trichomes contain chemicals that deter insects. In spinach, trichomes tend to be most dense on immature leaves at the center of the plant, and we hear about them most often in winter spinach as opposed to spring, summer, or fall crops. They are more common on certain varieties, but it’s not well understood whether or not there are specific environmental conditions that lead to their formation.

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Gleaning: Produce Safety Best Practices

-Written by Meredith Melendez, Rutgers New Jersey Agricultural Experiment Station. Originally published in the Rutgers Cooperative Extension Plant & Pest Advisory, February 4, 2025. https://plant-pest-advisory.rutgers.edu/gleaning-produce-safety-best-practices/

Allowing gleaners on your farm is a wonderful way to provide nutritious high-quality food to food insecure communities. Gleaners can unknowingly contaminate produce, a thirteen minute training video has been developed for volunteer gleaners focusing on produce safety.  This video is available on the Rutgers NJAES YouTube site and soon on the Rutgers On-Farm Food Safety site. A companion quiz was created for use to take after watching the video to test the knowledge of the gleaner on best practices.  A certificate of completion is displayed once the questions have been answered correctly.  We encourage farmers and gleaning organizations to stress the importance of produce safety during the gleaning process through education and support the health and hygiene practices of gleaners.  Best practices covered in the video are discussed in the Q&A below.

How should a farm support gleaner health and hygiene?
The gleaning organization should be aware of what you expect to supply gleaners while they are at your farm and know what they need to provide themselves.

• Restrooms and hand washing stations should be available in the location that gleaning will take place
• Restrooms and handwashing stations should be stocked and ready to use
• First aid supplies should be provided at a central location

What information should you supply the gleaning organization?
Clear communication channels before and during the gleaning process are important!

• The contact information of the person at the farm who is responsible in case there is an emergency, or if something goes wrong
• Location/s at the farm where gleaners are permitted to harvest
• Location of restrooms and handwashing stations
• Crops that will be harvested and any needed tools or containers that the gleaning organization should provide
• Information specific to animal activities in the field that could result in feces in the field or feeding damage from wildlife
• Any areas of the farm that gleaners must not enter

What information should the gleaning organization communicate to gleaners before they arrive at a gleaning event?
While many gleaning events happen last minute, and gleaner participation may be tentative, it is important that this information is shared with them prior to the event to help facilitate good practices.

• Signs and symptoms of illness that would prevent them from gleaning
• Appropriate clothing to wear while gleaning
• Hand jewelry should not be worn while gleaning
• Tools and gloves from home should not be used, gleaners should only use items supplied by the farm or the gleaning organization
• Snacks and non-water beverages are not permitted in the field
• The training video should be viewed prior to all gleaning participation

What information should gleaners understand about identifying produce that is safe to glean?
Gleaners should understand what produce can and cannot be harvested.

• Do not harvest produce that has fallen off of the plant and is on the ground
• Do not harvest produce that was dropped on the ground during harvest or transportation
• Do not harvest produce that is visibly contaminated with fecal matter
• Do not harvest produce that may be contaminated with fecal matter

What information should the farmer share with the gleaning coordinator and gleaners once they have arrived at the farm?
Information should be provided to gleaners at the start of the event to remind them of your expectations while gleaning. Volunteers showing up late must be informed of this same information and should know to check in with the gleaning coordinator.

• Restroom and handwashing station locations
• Importance of washing hands including when to wash them
• First aid kit and injury handling procedures
• Harvesting procedures and how to use tools if needed
• The process to avoid placing harvest containers on the ground, such as using a bottom bin to stack on top of with other bins, with the bottom bin not harvested into
• Gleaners should not use tools or gloves from home

What behaviors should I expect to see gleaners doing while gleaning to ensure produce safety?

• Not eating or drinking non-water beverages in the field
• Not eating produce while they are gleaning
• Washing hands at appropriate times:
  • Prior to the start of gleaning
  • After using the restroom
  • After eating, drinking, smoking
  • Anytime their hands may become contaminated
• Awareness of and staying away from fecal material in the field
• Communicating with the gleaning coordinator when:
  • Fecal material found in the field
  • An injury occurs
  • Someone begins to feel ill
  • Restroom or handwashing facility issues

For more information on produce safety, and details on why the above best practices were targeted for the harvesting of produce visit the Rutgers On-Farm Food Safety Essentials webpage.  To access the gleaner produce safety training visit the Rutgers NJAES YouTube channel: https://www.youtube.com/watch?v=grIGTneupd8 

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Food Safety Risks of Personal Belongings - Factsheet and Visual SOPs

Personal items, such as cell phones, gloves, or bags, may carry microbial contaminants and pose food safety risks on farms. A new set of resources is available to help growers consider and manage those risks.

The Personal Belongings Factsheet and associated visual SOPs were created to help growers and workers consider the food safety risk of personal belongings on produce operations. The factsheet outlines suggested risk mitigation policies for various personal belongings. It can be printed out and used as an educational resource. The associated visual SOPs are meant to be printed and hung up around operations to help implement these practices.

Personal belongings covered in this factsheet include:

• cellphones,
• jewelry,
• gloves,
• personal items such as bags, clothes, lunch boxes etc., 
• shoes/boots, and
• other personal belongings to consider.

The links include:

• a printable two-page factsheet,
• the same factsheet in a one-page poster size,
• a cellphone cleaning visual SOP,
• a visual SOP on avoiding using cellphones in bathrooms,
• a watch/jewelry cleaning visual SOP, and
• a glove cleaning visual SOP.

The work was completed by Anna Loewald, NECAFS/UVM, Elizabeth Newbold, NECAFS/UVM, Lisa McKeag, UMass Extension, and Robert Hadad, Cornell Extension

This project was funded by the Food Safety Outreach Program grant no. 2020-70020-32264 from the USDA National Institute of Food and Agriculture.

News

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Events

UMass Extension's Pollinator Steward Certification Program

When: On demand. You will have on-demand access to lectures and course content at any time, within a defined course period. Once registered, you will have 90 days to complete course content and schedule your end-of-course meeting.

Where: Online via Canvas

Registration: $199 per person through February 28. $249 after March 1. Click here to register.

UMass Extension’s Pollinator Steward Program includes lectures on foundations of pollination ecology, unique pollinator groups, habitat provisioning, and beyond. Learn practical applications and receive checklists for provisioning resources that pollinators need to survive, such as nesting sites and floral resources. Review discussions on management, such as pruning, pesticides, aesthetics, site evaluation, and more. Students will come away with a well-rounded understanding of how to create and manage pollinator habitat, as well as educate others on the creation, maintenance, and importance of such habitats.

This course specifically highlights pollinators in and around New England, as well as regional considerations for pollinator habitat. Key concepts are applicable anywhere. This program is designed for home or community gardeners, professional landscapers, pollinator enthusiasts, or anyone else looking to learn more about pollinator ecology and habitat management!

Click here for full program agenda.

What you receive:

• 6 self-paced online modules containing materials and additional resources
• 30 recorded lectures, including 13 guest lectures from various pollinator experts
• Discussion boards and the ability to network, share, and ask questions with other students
• Opportunity to connect 1:1 with UMass Extension at the end of the course to ask questions, discuss future directions, etc.
• Upon successful completion, a Pollinator Steward certification through UMass Extension

MDAR’s Farm Transfer Planning Assistance Program - Farm-Pass

When: Starting March 2025

Registration: Free. Rolling applications accepted. Apply by January 15 to begin work this spring. See program page for application information, HERE.

This program is for Massachusetts farm owners who have already identified a successor interested in transitioning ownership and management of the farm. Work one-on-one with an experienced planner over the course of a year to set retirement goals and create tangible next steps for the transfer of management and assets. Note that these advisors have experience working with farm operations on business management, financials, and farm transfer. They will not provide legal or tax advice but will help you develop an action plan that identifies concrete next steps to work on with your attorney and/or CPA to make the transfer happen.

Click here to view an informational webinar from Dec 11.

Questions? Contact Laura Barley at 857-507-5548 or Laura.Barley@mass.gov. 

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Vegetable Notes. Maria Gannett, Genevieve Higgins, Lisa McKeag, Susan Scheufele, Alireza Shokoohi, and Hannah Whitehead, co-editors. All photos in this publication are credited to the UMass Extension Vegetable Program unless otherwise noted.

Where trade names or commercial products are used, no company or product endorsement is implied or intended. Always read the label before using any pesticide. The label is the legal document for product use. Disregard any information in this newsletter if it is in conflict with the label.

The University of Massachusetts Extension is an equal opportunity provider and employer, United States Department of Agriculture cooperating. Contact your local Extension office for information on disability accommodations. Contact the State Center Directors Office if you have concerns related to discrimination, 413-545-4800.