Vegetable Notes 2026 Vol. 38:9

Pest Alerts

Brassicas

Imported cabbageworm adults (cabbage whites) are beginning to lay eggs now. Scout undersides of leaves for oblong yellow-white eggs, ~3 mm long, laid singly, on-end so you can be ready with an insecticide when caterpillars are present. Labeled conventional products include spinosyns (e.g. Radiant), pyrethroids (e.g. Warrior, Mustang, many others), diamides (e.g. Vetica and Coragen for soil or foliar applications or Exirel and Verimark for soil applications only), Proclaim, Avaunt, and Torac. Diamide products are more expensive but are systemic, have long residuals, and will also protect against flea beetles and cabbage root maggot. Bt products (e.g. Dipel, Xentari) are the most effective OMRI-listed materials. Use a spreader-sticker to help materials adhere to waxy brassica leaves.

Diamondback moth (DBM) caterpillars were also observed feeding on broccoli and cabbage in Hampshire Co. this week. These caterpillars have a forked tail-end and will wriggle and drop on a thread of silk when disturbed. Their feeding causes small, round holes that don’t break through the top layer of leaf tissue, leaving translucent films across holes, called “windowpane” damage. DBM has become resistant to many synthetic and microbial insecticides so be sure to rotate between IRAC groups, even if you’re currently getting good control. The materials listed above for imported cabbageworm are effective for DBM too—newer materials and the aizawai strain of Bacillus thruingiensis (i.e. Xentari) will usually provide better control of resistant DBM than older products.

Brassica downy mildew was seen this week on the outer leaves of Caraflex cabbage that was beginning to head. This disease usually causes patchy yellowing on the tops of leaves, with crusty-looking, white sporulation on the undersides. Lesions can have black veins. It often begins in seedlings in the greenhouse but continues to develop in the field. The disease is often very crop and even variety specific, popping up sporadically in the greenhouse or field on just one brassica crop out of many planted side by side. For effective chemical control, fungicides must be applied before or as soon as symptoms develop. See the appropriate brassica crop disease control section of the New England Vegetable Management Guide for labeled materials.

Chenopods

Cercospora leaf spot was identified on Boro beet seedlings in a greenhouse in Hampshire Co. this week. The early infestation and the fact that symptoms did not initially appear on other beet varieties present implies that the inoculum came on the seed. This fungus causes round tan spots that are surrounded by a red halo on red beet varieties (red halo is not present on gold or chioggia beets). The leaf spots will expand and coalesce into large blighted areas as the disease develops. The pathogen survives on crop residues in the field and can infest seed. Till under infested crop residue promptly to speed up decomposition. Chemical control is possible if materials are applied early and regularly. Research from Cornell has shown that Tilt (FRAC Group 3) is the most effective conventional fungicide. Resistance to FRAC Group 11 fungicides (e.g. Quadris, Cabrio, Flint) has been documented; do not rely on Group 11 materials alone for Cercospora control. The most effective OMRI-listed material is copper. See the beet and Swiss chard disease control section of the New England Vegetable Management Guide for a full list of labeled materials. 

Nightshades

Colorado potato beetle (CPB) adults are continuing to emerge, mate, and lay eggs in eggplant and potato. If you plan to control CPB with insecticides, scout now for yellow-orange eggs laid in clusters on undersides of leaves, and then monitor for egg hatch so that you can apply a material to target the smallest larvae. See the article in this issue for details.

Sweet Corn

European corn borer flight has theoretically begun, based on GDDs, but no moths have been trapped in pheromone traps so far. ECB moth capture in pheromone traps indicates to growers to start scouting their corn for ECB eggs and caterpillars; scouting results then determine the necessity to spray or not.

Corn earworm was captured at 2 farms in eastern MA this week. These are moths that would have overwintered here in MA, instead of blowing up on storm fronts from the south as this pest has historically done. CEW moths only lay eggs in silking corn so MA corn crops are not yet at risk of damage, but the early presence of this pest means that corn will be at risk as soon as silking begins.

Multiple Crops

Onion thrips adults and nymphs are present now in onion and brassica fields. Thrips are tiny insects, about 2 mm long, that feed with rasping mouthparts on leaf tissue. Their feeding causes patchy, silvery damage on alliums and brown, raised scarring on brassicas. This feeding damage lowers yield and creates entry points for bacterial pathogens. Thrips often hide in the growing points of allium crops during hot, sunny days and come out to feed in the cool mornings and evenings or during cloudy days. In alliums, scout now and count the number of adults (darker brown) and nymphs (lighter tan) per plant. Note the number of leaves per plant and determine the average number of thrips per leaf. Treatment is warranted if thrips reach 1-3 per leaf; use the lower threshold during bulb expansion, if expected efficacy of the insecticide to be used is low, water availability is limited, or other conditions reduce the overall health of the plants. See the insect control section of the appropriate crop in the New England Vegetable Management Guide for labeled insecticides.

Tarnished plant bug is active now, feeding on a variety of crops and weeds. These are brown, tan, or greenish, shield-shaped insects that have piercing-sucking mouthparts used to penetrate plant tissues and suck up cellular contents. Many vegetable crops are hosts to TPB, but we mostly often see significant damage in strawberry and lettuce. In strawberries, feeding damage causes catfacing of fruit. In lettuce, feeding damage causes discoloration and scarring on leaf midribs. It is difficult to control TPB with insecticides because they are so prevalent in the environment. Vegetation control on the whole farm will help to reduce overall TPB populations.

Herbicide Carryover Damage in Tomato from Grass Clippings

Last week the UMass diagnostic lab received a tomato sample that most likely had herbicide damage. The plants were grown in bags in a high tunnel with compost blended into the growing media. Unfortunately, grass clippings that were incorporated into the compost were the source of the herbicide contamination. This seemingly unlikely event is more common than you may expect.

There are three herbicide active ingredients that can remain intact in plant material for several years: picloram, clopyralid, aminopyralid. These are all highly selective synthetic auxin mimics (HRAC group 4), meaning that they only kill susceptible plants or plant groups that rely on that specific target auxin to grow. These products are all systemic, meaning they enter the plant and then travel to specific areas of the plant. Specifically, these active ingredients are all 6-Chloropicolinates¹. When applied to susceptible weeds—many of which are very difficult to kill with other herbicides—the products enter all the plants they were applied to, but only kill the susceptible ones. The remaining, living, plant material that also contains the herbicides can then cause damage to crops like the damage seen in tomatoes last week.

The picloram, clopyralid, and/or aminopyralid that remain in the tolerant plants (plants that weren’t killed by the herbicide) can remain intact for a long time. These active ingredients are broken down several ways, such as through photodegradation and microbial activity, but since both microbial activity and sunlight vary dramatically, it’s hard to know how long these active ingredients will remain viable. It can be as short as 30 days, or as long as several years.

Clopyralid can be used in some fruit and vegetable crops but these three chemicals are primarily used in hay fields, pastures, and lawns because they do not kill grasses. Therefore, these chemicals primarily end up in vegetable production either on hay or straw, or in animal manure. When animals are fed pasture, hay, straw, or forage that was treated with these products, the active ingredients can remain active in their manure after passing through the digestive system. These products do not harm the animals but can harm susceptible vegetables that are grown in soil amended with the animal manure or even compost made from their manure.

Usually the labels of these products require that all plant material treated with these herbicides remain on the field for at least a full year to avoid any issues. For example, pasture treated with aminopyralid cannot be cut for hay and livestock that graze that pasture must remain on the field long enough that their manure stays in place. However, sometimes mistakes are made and material that has been treated with these products leaves the field. It’s not hard to imagine that a field treated with aminopyralid could be harvested and sold for hay, with the harvester not understanding the consequences. And then a livestock farmer could feed the hay to their cows without any issue and unknowingly sell the contaminated manure to a local vegetable farm. This vegetable farm might then experience crop stunting or death when planting into beds amended with the manure.

Hopefully everyone reads and follows herbicide labels carefully. However, there are several things you can do to reduce the chances that this happens to you. First, try to understand the origin of the plant-based material you bring to your farm. If you purchase straw, hay, or grass clippings, ask what herbicides were applied to the crop. If you purchase manure or compost, ask about the origin of the animal feed or compost ingredients. Hopefully you’re able to purchase amendments from sources you trust. If not, you can also conduct a bioassay: plant 1-2 susceptible plants into the material of concern. Tomatoes and beans are two very susceptible plants, but you can find a longer list (as well as more information) in this North Carolina State Extension fact sheet. When doing the bioassay, give the plants a chance to grow and express damage—these systemic products can take a little bit of time to act. Look for abnormal growth such as twisting and puckering. To avoid misdiagnosing herbicide carryover issues, plant a “control” bioassay in soil not amended with the material of concern. If both the treated and control plants are showing poor growth, maybe something else is the issue such as water stress or a virus.

References:

1. Global Herbicide Classification Lookup. Herbicide Resistance Action Committee https://hracglobal.com/tools/classification-lookup.

--Maria Gannett, UMass Extension Weeds Specialist

Colorado Potato Beetle Management

Including information on newly registered insecticides for conventional control 

Colorado potato beetle (CPB) adults are now emerging from their overwintering sites across Massachusetts and have started laying eggs in some locations. This pest can quickly skeletonize potato and eggplant leaves and does significant damage to these crops every season. Early control is especially critical for CPB because larvae cause over 85% of damage and are much more susceptible to insecticides due to their small size, lack of a hardened exoskeleton, and heavy feeding habits which result in them ingesting a greater dose of insecticide. Good control of CPB in June will not only protect vulnerable crops now but will also reduce the number of beetles in the next generation that will overwinter to feed on next year’s crops.

Life Cycle

In the Northeast, CPB feeds on solanaceous crops and weeds including potato, eggplant, tomato (primarily seedlings), horsenettle, and Eastern black nightshade. CPB overwinters in the adult stage, generally in soil in the woods and brushy borders next to host crops, though some burrow into soil right in the field. In late spring, the beetles emerge to search for host plants. Adult CPB are fairly slow and clumsy; they can fly when temperatures are warm enough, but more often they walk into fields from overwintering sites. Heavy feeding may occur on edges of non-rotated fields. If beetles do not find host plants via walking, they will fly in search of food. Once they reach a host plant, adults feed, mate, and lay clusters of yellow-orange eggs on the undersides of leaves. One female can lay up to 300 eggs in her lifetime. Eggs hatch in 7 to 10 days, depending on temperature. The larvae are reddish-orange and grub-like with rows of black spots along the sides of their abdomen. They, along with the feeding damage they cause, are easily seen on leaves. Larvae go through four molts before they pupate—each stage of the larva is called an “instar”. In the first instar, the larvae are about the same size as the eggs and in the second instar they are about ⅛” long. Mature, fourth instar larvae are hump-backed and plump, and reach ⅝” before they drop to the soil and pupate. Adults emerge from pupae after 10 to 14 days, leaving round exit holes at the soil surface. In southern New England, there is a second generation of eggs, larvae, and adults in late July, while there is only one generation in northern New England. Beetles fly or walk out of fields in August, seeking overwintering sites at field edges.

If you are getting near the spray threshold, pay extra attention and scout again in 3-4 days. The New England Vegetable Management Guide recommends this tighter scouting schedule if numbers are above 15 adults, 75 small larvae, or 30 large larvae per 50 plants/stalks. 

Use these scouting sheets to help keep track of the CPB populations: Potato, Eggplant, Tomato. These can be used for several different insects and diseases in each crop.

Controls & Prevention

• Rotation. The single most important tactic for CPB management is to rotate potatoes, eggplants, and tomatoes to a field that is at least 200 yards from the previous year’s fields. Barriers such as roads, rivers, woodlands, and fields with other crops are helpful, because CPB adults are such slow and clumsy movers. This single practice delays and reduces colonization by adults, subsequently reducing the number of eggs and larvae in the field.
• Crop health. Starting with healthy seed/seedlings and maintaining good crop nutrition helps plants grow well and withstand feeding injury.
• Straw mulch. It has been well documented that when potatoes or eggplants are mulched with straw, fewer CPB adults will settle on the plants and fewer eggs will be laid. This can be accomplished on larger plantings by planting into a rye cover crop, mowing down the rye, then pushing the rye straw over the plants after they emerge. For smaller plots, straw may be carried in.
• Perimeter trap cropping. Potato trap crops may be planted earlier than the main crop to attract beetles before the main crop emerges or planted between overwintering sites and this season’s crop. Flame, vacuum, or spray the border crop before beetles move into the main crop. Another approach is to plant 3 to 5 rows of potatoes treated with a systemic insecticide in a perimeter around the field; this treated border will kill up to 80% of the colonizing beetles. Planting main potato crops later than normal may also cause beetles to leave the field before potatoes emerge, resulting in lower beetle numbers.
• Trenches. This is a common recommendation, but we’ve never actually seen it in practice! The recommendation is to install plastic-lined trench traps next to overwintering sites at least 1 week before adults emerge, with trenches 1 - 2’ deep and 6 - 24” wide at the top. They can be U- or V-shaped with side walls sloping at angles between 65° and 90°. Beetles walking from field borders fall into the trench and cannot fly out. Let us know if you’ve ever tried it and if you’ve run into any pitfalls (maybe literally!).
• Flaming.  Flame weeders can be used to kill colonizing adult beetles in potatoes when the crop is less than 5” tall. Move rapidly using a tractor-mounted or hand-held flamer. The goal is to scorch beetles, not burn them to death—burning them to death will result in excessive plant damage, while scorching their antennae and legs will render them unable to orient and climb plants. At this early stage, healthy emerging potatoes have sufficient reserves to regrow foliage and establish well.
• Biological control. Naturally occurring predators and parasites of CPB help suppress populations and prevent crop injury. Natural enemies that attack CPB eggs or larvae include twelve-spotted lady beetle (Coleomegilla maculata), spined soldier bug (Podisus maculiventris), a ground beetle (Lebia grandis), and a parasitic tachinid fly (Myiopharus doryphorae). The fungus Beauvaria bassiana (sold as the insecticides Mycotrol and Botanigard) has been shown to suppress beetle populations, though it does not provide immediate control. Using selective rather than broad-spectrum insecticides can help to conserve these natural enemies. Be aware that lady beetle egg masses look very similar to CPB egg masses, but lady beetle eggs are more yellow and slightly smaller (~1mm) than CPB eggs (~1.7 to 1.8mm), which are also more orange.
• Hand removal. For smaller plantings and early infestations, walking through the crop to squish egg masses or drop adults into buckets of soapy water can be very effective to delay the build-up of damaging populations. Some growers use tennis rackets to knock beetles off plants more quickly. 
• Mechanical devices have been created to facilitate physical removal of beetles from plants more efficiently at larger scales. Many of these are homemade, but some growers have provided guidance detailing their process. For more information, see the article in our first issue from last year, originally written by Chris Callahan and Andy Chamberlin of University of Vermont Extension. 

Chemical Control

Before spraying, scout to determine if a damaging population is present. Labeled conventional products include pyrethroids, neonicotinoids, novaluron (e.g. Rimon), cyromazine (e.g. Trigard), and diamides (e.g. Verimark, Exirel). In recent years, we have observed resistance to both neonicotinoids (e.g. Assail, Belay, Venom, Actara, Cruiser, Platinum) and synthetic spinosads (e.g. Radiant) in New England. When using products that control only larvae or only small larvae, scout for eggs, note egg hatch, and apply controls before larvae reach third instar to avoid the worst feeding injury. For materials that control all stages, you may wait and scout for adults and larvae to determine the need to apply insecticides.

For organically managed fields, the selection of insecticides is limited to fewer active ingredients including spinosad (Entrust), azadirachtin (Azatin), pyrethrin (Pyganic), and Beauvaria bassiana (Mycotrol O, Botanigard), which can be tank-mixed and/or rotated. The Bt product Trident, which was developed a few years ago for CPB control, is still off the market due to formulation issues and there are no plans to reintroduce it. With few products to choose from, it’s more important to time pesticide applications so that they are as effective as possible and therefore reduce the need for subsequent applications.

Calantha is a new insecticide that was recently registered by the EPA for controlling CPB and contains Ledprona as the active ingredient. It was registered in Massachusetts in 2025 and is the first sprayable insecticide utilizing a novel mode of action based on RNA interference (RNAi). RNAi is a natural biological process which exists in most organisms and regulates the translation of messenger RNA, one of the steps of protein synthesis. Ingestion of specific manufactured double-stranded RNA (dsRNA) can activate this interference process in some organisms such as CPB, disrupting the production of a vital enzyme in the insect’s metabolism and resulting in mortality within a few days of consumption. While the potential for dsRNA technology to cause non-target effects has been shown in other scenarios (i.e. with other dsRNA products and other organisms), field studies of Ledprona have not found any significant negative effects on non-target arthropods. This, along with dsRNA’s rapid degradation in the environment, may allow for a decrease in environmental impacts stemming from CPB management. However, like with any other insecticide, resistance to RNAi-based biopesticides is likely to emerge if resistance management strategies are not used. Cautious use of this insecticide in combination with other IPM principles shows promise as a method of providing effective control of CPB while mitigating environmental risks. For more information, see our article on Calantha from earlier this year. 

Zivalgo is another newly registered insecticide that is labeled for CPB, which uses the active ingredient isocycloseram, marketed as Plinazolin. Along with products like Incipio (formulated for cucurbits, brassicas, and leafy greens) and Vertento (formulated for onions), Zivalgo falls under the new IRAC Group 30 and functions by disrupting nerve signal transmission in insects, resulting in death. It primarily acts upon contact, but also has some residual and translaminar activity which help it provide more thorough control. While there is not yet any known resistance to this active ingredient, CPB populations are exceptionally prone to developing resistance to new insecticides and must be managed carefully to prolong the effective life of the product. See the paragraph on resistance management below for details.  

Because of its broad-spectrum and residual activity, the active ingredient in Zivalgo can be harmful to beneficial insects as well as fish and aquatic invertebrates that are exposed to runoff. Like other insecticides in this group, Zivalgo’s label includes use restrictions that must be followed to comply with the Endangered Species Act’s risk mitigation requirements. This is part of a long-term EPA approach in which similar measures will gradually be included in updates to all pesticide labels. Pay close attention to the listed restrictions on labels, which may include mandatory mitigation measures to reduce pesticide drift and runoff, as well as possible additional use restrictions depending on what, when, and where you will be spraying. To determine whether your application will take place in a “Pesticide Use Limitation Area” (PULA) and the additional mitigation measures that requires, you will need to access the EPA’s website, “Bulletins Live! Two” no more than 6 months prior to your planned application. While the number of PULAs in MA are so far limited and largely isolated to areas surrounding major bodies of water, more may be added as new products receive label updates. Ensure that you are following all labeled instructions and restrictions to protect vulnerable wildlife and comply with federal law. For more information about Endangered Species Act label updates, visit our article on the topic from earlier this year.

Do not try to kill every beetle in the field. Potato crops can withstand 15% defoliation without affecting yields. Avoid treating potatoes for CPB late in the season, as defoliation less than two weeks before senescence will have little effect on final tuber bulking.

Resistance management must be part of every potato grower’s plan. CPB has a remarkable capacity to develop resistance to insecticides. Based on a fifty-year track record, we can expect that any insecticide that is used repeatedly on the same population of CPB (that is, those in the same field or farm) will lose its efficacy in less than five years. Where potato production is concentrated and rotation has been limited, resistance may develop on a region-wide basis. It’s up to you to manage resistance in the population of beetles on your farm, and keeping insecticides effective with careful rotations is a worthwhile investment. In the New England Vegetable Management Guide, as well as on pesticide labels, each insecticide has an IRAC (Insecticide Resistance Action Committee) Group Number, which identifies chemistries with the same mode of action. Growers should note the resistance group number of each insecticide, rotate classes of insecticides, and avoid using the same chemistry more than once per year, or even better, once every other year. Do not use the same chemical class on successive generations in the same year. Use newer chemistries first. For conventionally managed fields, there are enough different products to do a two-year rotation that will effectively control CPB while effectively delaying resistance to any one product.

See the potato and eggplant insect control sections of the New England Vegetable Management Guide for full lists of labeled materials.

--UMass Vegetable Program

Irrigating Dry Plastic Mulched Beds

--Written by Emmalea Ernest, University of Delaware Extension Fruit & Vegetable Specialist. Originally published in Delaware Weekly Crop Update Volume 34:8, May 1, 2026.

We are having another dry spring, with challenging conditions for wetting mulched beds laid in dry soil. Ideally, it is best to form raised beds and lay plastic mulch when the soil moisture level is at or near field capacity. Field capacity is the point where all the water from a major rain event has run off or fully infiltrated beyond the root zone. Sandy soils will reach field capacity about 12 hours after a saturating rain or irrigation; heavier soils can take 2-3 days to reach field capacity after saturation. If plastic mulch is laid onto dry soils, it can be challenging and time consuming to fully wet the soil using only the drip irrigation system. Having dry soil in the bed not only interferes with crop water availability but also reduces heat accumulation in the soil.

If overhead irrigation is not available growers should prepare the soil and wait for adequate rain before pulling the beds. However, if time is tight and plastic must be laid with dry soil, shorter irrigation run times will be more effective in promoting movement of water throughout the mulched bed. On sandier soils and dryer soils, water moves down in the soil profile (and out of the root zone) more quickly. Sandy and dry soils also have less lateral movement of water, which is what makes it challenging to wet the full width of a bed (Figure 1).

Below is Table C-5 from the Mid-Atlantic Commercial Vegetable Production Recommendations, which lists maximum run times for drip irrigation on various soil types. There are several things to note about this information that can help you make decisions about maximum run times. On loamy sand soils (green shading), the maximum run time ranges from 1.7 hours for high flow tape to 5.1 hours for low flow tape. However, this recommended run time assumes that the crop is using water. If the crop has not yet been transplanted or is too small to be using significant amounts of water, cut the maximum run time in half. For the purpose of wetting dry plastic mulch beds early in the season the maximum run times are 50 minutes to 2.5 hours on loamy sand, and 1.6 to 4.9 hours on sandy loam. The time between irrigation runs should be at least two hours.

Understanding FSMA Agricultural Water Rules and Assessing Food Safety Risks

This article describes the importance of managing agricultural water to reduce food safety risks and gives an overview of the current water-related requirements under the FSMA Produce Safety Rule and Massachusetts Commonwealth Quality Program (CQP). 

Water and Produce Safety

Water that’s likely to contact produce or a food contact surface may contribute to food safety risks on a farm. Fecal pathogens, including those that are commonly linked to foodborne illness outbreaks, such as Salmonella, Listeria monocytogenes, and pathogenic E. coli, can survive in water for long periods of time and can be moved by water onto various surfaces on a farm, including onto fresh produce. Contaminated irrigation water was implicated in several recent outbreaks of foodborne illnesses, including Salmonella on whole red onions and E. coli O157:H7 on head lettuce.

Extreme weather events and the warming temperatures we’re seeing in the Northeast may exacerbate water quality issues. Microbial pathogens survive and are spread in fecal matter. Under drought conditions, animals may be more drawn to farm water sources if other sources are depleted and growers may be forced to use lower-quality water. On the other hand, heavy rain or flooding may wash fecal matter into water sources or churn up sediment that contains pathogens. Warmer temperatures increase microbial growth.

Because water is used in so many farm activities, both pre- and postharvest, water quality and managing the sources of fecal contamination of water in the farm landscape are big focus areas for food safety rules and programs.

Growers should routinely assess whether any water they’re using is likely to contain pathogens that might contaminate produce and should use practices that help to reduce the chances that contamination will get onto food. For growers subject to inspection under the Food Safety Modernization Act (FSMA) Produce Safety Rule (PSR), there are specific activities and records required to guide this assessment. Similarly, growers who participate in an audit program, such as Massachusetts’ state program, Commonwealth Quality, will have to comply with program rules, which may be stricter than FSMA requirements. 

The FSMA water rule

The FSMA PSR requires that “all agricultural water must be safe and of adequate sanitary quality for its intended use”. It defines agricultural water as water that is intended to, or is likely to, contact any fresh produce subject to the rule, as well as any food contact surfaces. All PSR requirements, including those related to water, are final as of 2024 and growers should be prepared to have their records available for inspectors; only very small farms under the FSMA definition—those grossing between $25,000 and $250,000— still have until 2027 to begin complying. See here for a summary of compliance dates and requirements. If you are unsure whether your farm is subject to FSMA PSR inspections, contact the MDAR Produce Safety Inspection Program, or if not in Massachusetts, the appropriate agency in your state. 

For recordkeeping purposes, it’s helpful to break the FSMA requirements down into 3 areas:

1. All agricultural water – Applies across the whole system
2. Preharvest water – Irrigation, crop sprays, frost protection
3. Postharvest water – Produce washing, handwashing, cleaning and sanitizing

1. All Agricultural Water

The PSR requires that, at the beginning of the growing season and at least once a year, growers inspect all agricultural water systems to identify produce safety hazards. The system must also be maintained to prevent contamination. Remember, the goal is to prevent fecal matter (which may contain foodborne pathogens) from getting into the water. For some water sources, such as ponds or brooks, it’s inevitable that animals—and their poop—will be in and near the water. The purpose of a routine inspection is to understand where the risks of contamination are and to the extent that it’s within your control, maintain the system to minimize these risks. 

It’s helpful (though not required) to start with a map of your farm and the water distribution system so you can visualize all of the components of the system from source to outlet (Fig. 1). At least annually, go out and look at all of the components. Some things to look for or note in your inspection record are below. (Many of these points came from a nice video from MSU Extension on doing a water system inspection.)

• The nature of each water source. Is it ground (well) water, surface water (e.g., river, pond, stream, reservoir, open holding tank), or municipal water?
• The extent of your control, degree of protection, adjacent land uses, likelihood of introduction of hazards
• Water sources are free of debris, trash, domestic animals, other possible sources of contamination
• Pressure sensors are working
• Check valves are functioning properly
• Well heads are locked
• Conduit pipe is present and secure enough to prevent access to insects and other animals
• Vent holes are screened
• Concrete pads are intact
• Equipment is stored to prevent contamination by animals

Finally, complete a water system inspection record. There is no specific format required for this record under FSMA rules, but a good template is in the Produce Safety Alliance’s document, Records Required by the FSMA Produce Safety Rule (see page 9) (Fig. 2).

2. Preharvest Water

The Rule requires that growers complete a written Agricultural Water Assessment at the beginning of the growing season, at least annually, and whenever there is a significant change that may impact risk. This assessment is different from the inspection in that it is only required for preharvest water and it requires consideration of some other factors beyond the components of the water system. The assessment must identify conditions that are reasonably likely to introduce known or reasonably foreseeable hazards onto covered produce or food contact surfaces. There are 5 factors that need to be considered in an Ag Water Assessment:

1. The Ag Water System – This is based on your system inspection and includes details about the source and location of the water and how protected it is from contamination.
2. Ag Water Practices – How do you use the water? In overhead or drip irrigation? In crop sprays? How close to harvest do you apply the water? Risk tends to be lower when water is not applied directly to the crop or when the time period between water application and crop harvest is longer.
3. Crop Characteristics – What crops are you applying the water to? Some crops have structures or surfaces that are rough or have crevices that may make them more susceptible to adhesion by pathogens, e.g., leafy greens, or cantaloupe.
4. Environmental Conditions – Consider both typical environmental conditions at times when water is applied, as well as extreme weather events such as drought or flooding, or hail or wind storms that might damage crops and make them more hospitable to bacterial growth. You may need to revisit your assessment after extreme weather. 
5. Other factors – The rule allows for other risk factors to be included in the assessment, including the results of water tests. 

Note that while the previous version of the Produce Safety Rule required growers to take a series of water tests for generic E. coli (an indicator of fecal contamination), the current rule does not require testing, though test results can still be a useful tool to include in an assessment.

If after conducting the assessment, you determine that the water is not safe or of adequate sanitary quality, you must stop using it and correct the issue before continuing use. If the water isn’t necessarily unsafe to use but there are conditions that may introduce risk, you must use mitigation measures to attempt to address them. If the risk is specifically related to animal activity, animal-based amendments, or human waste, it must be corrected promptly and no later than the same growing season. Mitigation measures might include making repairs to the system, changing how the water is applied (e.g., switching to drip irrigation), increasing the time between application and harvest, or if appropriate, treating the water to kill pathogens. 

An Ag Water Assessment is not required for water obtained from a public water system, as long as its quality is not likely to change before use (e.g., it’s not stored in an open cistern or otherwise exposed to contamination after it reaches the farm), or if it meets the standards for postharvest water (see next section). 

Tools and Templates:

• FDA’s Ag Water Assessment Builder
• Risk Prioritization Tool developed by Michigan and Minnesota Extensions
• Agricultural Water Assessment Questionnaire, developed by the Northeast Center to Advance Food Safety (NECAFS)
• Example recordkeeping template: Records Required by the FSMA Produce Safety Rule (see pages 10-11) (Fig. 3). 

3. Postharvest Water

Unlike the provisions for pre-harvest water, which were updated in 2024, requirements for postharvest water have not changed since the Produce Safety Rule was first published and growers are expected to already be in compliance with this part of the Rule. 

Water used in postharvest activities, that is, water used for produce cooling or rinsing, cleaning or sanitizing of food contact surfaces, handwashing, ice making, or any other direct contact with produce or food contact surfaces, must meet the following requirements:

• If untreated ground/well water – test for generic E. coli 4 or more times during the growing season or over the period of a year. Take 1 or more tests per year after initial year.
• If public water supply – obtain copy of test results or compliance certificate from municipality
• Untreated surface water cannot be used for postharvest activities
• Must have a plan for maintaining and monitoring the quality of recirculated and batch water

The required records for postharvest water are: 

• The results of water tests if using untreated ground water, or
• The compliance certificate if using municipal water and,
• If using sanitizer in produce wash water, any sanitizer treatment monitoring logs. 

State Requirements

The FSMA PSR is a federal regulation that sets minimum food safety standards for fresh produce farms. It is overseen by FDA but generally enforced by state regulatory agencies. In Massachusetts, the Department of Agricultural Resources (MDAR) Produce Safety Team conducts PSR inspections. Many states also have their own voluntary audit programs, or use the USDA-GAP program. These 3rd-party programs may  provide greater access to educational support or grants as well as the ability to receive a compliance certificate and use of program branding after a successful audit. These programs may have stricter requirements than the minimums set by the FSMA PSR. The Massachusetts Commonwealth Quality Program (CQP)—also implemented by the MDAR Produce Safety Team—is the state’s audit program. Its compliance criteria adhere to the PSR but also include some additional requirements. With respect to preharvest water, growers who choose to participate in CQP must:

• Test each surface water source 3x per year for generic E.coli
• Test each ground water source 2x per year for generic E.coli
• Obtain a quality compliance certificate for municipal water sources
• Meet the threshold for water tests of 126 CFU generic E. coli/100 ml water sample

For a summary of audit program requirements in the 6 New England states, see New England Food Safety Audit Program Water Requirements. 

Conclusion

Regardless of whether you need to comply with FSMA or CQP requirements, you should consider whether any water you use on your farm is likely to contribute to the spread of foodborne pathogens to fresh produce and use measures to mitigate the risks you find. 

If you want help with understanding your water risks, conducting an assessment, or knowing how and when to take water tests, please reach out! We’re always happy to come by your farm or share resources. UMass Extension also has some limited supplies for taking water tests and providing results—contact Lisa McKeag, lmckeag[at]umass[dot]edu (lmckeag[at]umass[dot]edu) or 413-658-8631 if you’re interested in water testing. 

--Written by Lisa McKeag, UMass Extension

News

USDA Announces Enrollment Period and Payment Rates for Specialty Crop Farmers

Enrollment period: June 1 (online) or June 8 (at FSA) through August 7.

Application and payment details for USDA’s Assistance for Specialty Crop Farmers (ASCF) program have been released. These payments are intended to provide financial support to allow producers to pay for production and marketing inputs in the face of significant market disruptions during the 2025 growing season.

Eligibility: All field-grown vegetable crops are eligible; crops grown in protected culture (high tunnels or greenhouses) are not eligible. Crop insurance is not required to be eligible for this program.

How to Apply: Producers who have a Login.gov account and filed their 2025 crop acreage report can access and submit a pre-filled application starting June 1, 2026, HERE. Producers who do not have a Login.gov account can create one, or can apply in-person at their local FSA office. The ASCF enrollment period closes on August 7, 2026. Payments will be issued as applications are submitted and approved, beginning as early as the first week of signup.

Payment Calculation: Payment rates are based on the crops grown. Crops are split into 4 payment tiers based on national average revenue per crop. See the table below for payment rates. The ASCF payment limitation is $250,000.

More Information: Visit fsa.usda.gov/ascf or contact your local FSA county office.

Events

SEMAP & UMass Extension Twilight Meeting: Permanent Deer Fencing & Flower Pest Walk

When: Thursday, June 18, 2026, 5:30-7:30pm

Where: Langwater Farm, 215 Washington St., North Easton, MA 02356

Registration: Free! Dinner included. Please register in advance. Click here to register.

Interested in the process of building and installing permanent deer fencing? Join SEMAP for a wagon ride around Langwater Farm in Easton to see their deer fencing in action, including post pounding and brace building demonstrations. Langwater has been building and maintaining permanent deer fencing for years. This is a great opportunity to get your questions answered and find out if a similar fencing system is right for you. UMass Extension will then lead a pest identification walk through Langwater's flower fields. 

Save the Dates!

• All About Peppers – Twilight Meeting at Kitchen Garden Farm: Tuesday, July 21, Sunderland, MA
• Temporary Fence Installation & Maintenance: Thursday, September 17, 5-7pm, Heart Beets Farm, Berkley, MA