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Crop Conditions
Zucchini harvest has started, warm-season crops are being planted, and we even got a little rain this past week to give most farms a day off from just moving irrigation around. Insects are feeding, weeds are germinating, and even though it’s been dry, there are still diseases to worry about. In short, the season is in full swing. We’re feeling busy and we’re sure that you all are feeling even busier! Might feel like you’re in a tornado already, but as of this writing, parts of western and central MA are in an actual tornado watch, while the rest of the state is at risk of severe storms. Stay safe out there! Keep an ear on the radio for updates, and see the National Weather Service for their tornado safety rules.
Contact Us
Contact the UMass Extension Vegetable Program with your farm-related questions, any time of the year. We always do our best to respond to all inquiries.
Vegetable Program: 413-577-3976, umassveg[at]umass[dot]edu (umassveg[at]umass[dot]edu)
Staff Directory: https://ag.umass.edu/vegetable/faculty-staff
Home Gardeners: Please contact the UMass GreenInfo Help Line at greeninfo[at]umext[dot]umass[dot]edu (greeninfo[at]umext[dot]umass[dot]edu).
Pest Alerts
Alliums
Onion thrips: Scouted fields in eastern MA are getting up to threshold. The treatment threshold is one thrips per leaf; once thrips begin to outnumber leaves on plants, it’s time to spray. For highly effective products and otherwise healthy plants, you can use a threshold of up to three thrips per leaf.
Cucurbits
Squash vine borer (SVB) traps are up and 2 out of 5 locations reported moth captures this week (Table 1). Peak flight usually occurs in late June/early July. SVB eggs are laid at the base of susceptible cucurbit plants (any thick stemmed cucurbit) and the larvae tunnel straight into the stem. Infested plants will wilt, yellow, and eventually die back. Root rots, drought, waterlogged plants, and bacterial wilt can all cause similar symptoms to those caused by SVB infestation, so it’s important to get an accurate diagnosis before taking action. SVB larvae will leave behind an entry hole and a large pile of frass; slice open the stem to find the cream-colored larva that can grow up to 1.5 inches long. Pesticide applications are timed using pheromone trap captures; when 5 moths per week are captured, pesticide applications should be initiated. Materials used for control of hatching SVB larvae include pyrethrins, pyrethroids, carbaryl, as well as Bacillus thurigensis (Bt) toxin formulations, especially those made from B. aizaiwi.
| Table 1. Squash vine borer trap captures for week ending June 17. | |
|---|---|
| North Easton | - |
| Sharon | 0 |
| Lexington | 1 |
| Leominster | 0 |
| Whately | 4 |
| Westhampton | 0 |
Nightshades
Colorado potato beetle (CPB) larvae are actively feeding in potato and eggplant now. Newly hatched larvae are most susceptible to insecticides, while larger larvae are highly tolerant to pesticides and also cause 85% of feeding damage to the crop, so early management targeting the smallest larvae is critical. CPB quickly develop resistance to any pesticides used back-to-back, so do not use products in the same IRAC Group as the products you used last year to control CPB. There are enough options for conventional growers to do this; see the eggplant or potato insect management sections of the New England Vegetable Management Guide for labeled materials. Incipio, a newly registered foliar insecticide, is labeled for control of CPB on the fruiting vegetable crop group (which includes eggplant) at 2.1-4.1 fl oz/A and the same active ingredient is labled for potatoes as Zivalgo at 0.7-2.0 fl oz/A. For organic growers, Entrust SC is the most effective but should only be used on the spring generation—make sure to get the most out of your 2 allowed applications by waiting for the eggs to start hatching and making another application 1 week later. Picking beetles and larvae off by hand, flaming to scorch beetles antennae, and physically knocking larvae off of plants are other effective non-chemical control methods.
White mold was diagnosed on high tunnel tomatoes this week. Classic symptoms are whole stems or plants that are dying back, and stems that crack open to reveal fuzzy white fungal growth and hard, black sclerotia that look like raisins. This disease is caused by a fungus that produces spores in the spring that often infect senescent tomato flower tissues. From there, the fungus moves into the main plant. As the disease develops, the fungus produces sclerotia within infected tissue, which act as survival structures for the fungus to overwinter. Sclerotia can survive in soil for many years. If you confirm white mold in your tunnel or field, remove dispose of infected plants. White mold has a wide host range and can infect many vegetable crops. The biocontrol agent Coniothyrium minitans, sold as the product Contans, can reduce the viability of sclerotia in the soil—Contans cannot be applied directly to tomatoes but can be applied to other labeled vegetable crops to act on sclerotia and manage the disease in a subsequent tomato crop.
Three-lined potato beetle adults were seen feeding on husk cherries in Middlesex Co. These insects will feed on potato and other solanaceous crops but strongly prefer tomatillo. Larvae resemble Colorado potato beetle larvae but, distinctively, carry a pile of their own feces on their back. Many growers choose not to treat for this pest because they are concentrated on tomatillos, which are often a minor crop. Labeled materials include Radiant, Agri-Mek, and pyrethroids. Entrust is the most effective OMRI-listed material. Control solanaceous weeds.
Two-spotted spider mites (TSSM) were observed in high tunnel tomatoes this week. These are tiny mites that feed on the leaves of many different vegetable crops, causing leaf stippling and senescence. Large populations produce visible webbing that can completely cover leaves. TSSM are favored by hot, dry conditions. Early intervention is essential for controlling spider mites. Preventative releases of the predatory mites, Phytoseiulus persimilis and Amblyseius fallicis may suppress TSSM. If controlling TSSM with insecticides, use selective products that will not affect beneficial insects that may be keeping other pests in check. Labeled conventional materials include Acramite, Agri-Mek, Movento, and Oberon. The most effective OMRI-listed materials are insecticidal soaps (e.g. M-Pede) and/or oils (e.g. Trilogy, Golden Pest Spray Oil).
Sweet corn
European corn borer moths continue to be caught in pheromone traps in low numbers this week, with both the NY, IA, and hybrid traps catching moths (Table 2). Moth capture indicates that caterpillars are present or will soon be present in the field and growers should begin scouting. Scout for flagged tassels and/or shot hole feeding damage in horizontal lines on leaves. See the Sweet Corn Insect Management Field Scouting Guide for instructions on sequential scouting and thresholds.
Corn earworm (CEW) moths were captured in 4 additional locations this week (Table 2). This is the time of year we have historically seen CEW arriving in the Northeast from southern overwintering sites. Most trap locations either do not require a spray or require the widest spray interval. CEW strongly prefers laying eggs in silking corn so sprays may not be necessary if growers do not have silking corn yet.
| Table 2. Sweet corn trap captures and growing degree days for week ending June 17 | |||||||
|---|---|---|---|---|---|---|---|
| GDDs (base 50°F*) | Trap Location | ECB NY (2) | ECB IA (1) | ECB Hybrid | FAW | CEW | CEW Spray Interval |
| Western MA | |||||||
| 695 | Northampton | - | - | - | - | .5 | no spray* |
| 759 | Whately | 2 | 0 | 3 | - | 2.5 | 6 days |
| 671 | Southwick | 2 | 0 | - | 0 | 4 | 5 days |
| n/a | Feeding Hills | 1 | 1 | - | 0 | 1 | no spray* |
| Central MA | |||||||
| 715 | Leominster | 0 | 0 | 0 | 0 | 2 | 6 days |
| 695 | North Grafton | 0 | 0 | - | 0 | 0 | no spray* |
| 665 | Spencer | - | - | - | - | - | N/A |
| 696 | Bolton | 0 | 0 | - | - | 0 | no spray* |
| n/a | Townsend | 0 | 0 | - | 0 | 0 | no spray* |
| Eastern MA | |||||||
| 719 | Concord | 2 | 0 | 0 | 2 | 6 days | |
| 679 | Haverhill | - | - | - | - | - | N/A |
| 641 | Ipswich | 2 | 2 | - | 0 | 6 | 5 days |
| n/a | Millis | 3 | 0 | - | - | 1 | no spray* |
| 694 | North Easton | - | - | - | - | - | N/A |
| Sharon | 0 | 0 | 0 | 0 | 0 | no spray* | |
| n/a | Sherborn | 5 | 1 | - | 0 | 2 | 6 days |
| 785 | Seekonk | 2 | 0 | 1 | 0 | 2 | 6 days |
| Swansea | 1 | 0 | - | - | 2 | 6 days | |
| - trap count not available *GDDs are reported from the nearest weather station. If no weather station is nearby the trapping site, no GDDs are reported. | |||||||
Berry Blast
This has been a busy week for berry growers. Last week brought a hard swing in weather, with a stretch of heat and strong sun followed by sporadic heavy rain and storms in some locations. That kind of weather is hard on fruit. Heat can push crops forward quickly, while heavy rain on ripe fruit can lead to soft spots, cracking, and increased disease pressure. Looking ahead, the rest of this week looks more manageable, but growers should still keep an eye on scattered showers or storms. Friday into the weekend looks drier, breezier, and more seasonable. The main recommendation for the rest of the week is to stay ahead of harvest, avoid unnecessary field traffic when plants are wet, and tighten up disease scouting after any rain.
We are also coming to the end of the fertilizer application window for most perennial fruit crops. For blueberries, brambles, and grapes, I do not recommend nitrogen applications after June 30. Late nitrogen can push soft late-season growth, delay hardening off, and increase the risk of winter injury. Strawberries are the exception here, especially June-bearing matted-row plantings, where renovation and postharvest fertility are part of the normal production cycle.
Strawberries are good and bad this week. The good is that markets are open across the state, and the crop is looking strong. Early varieties such as Wendy are being harvested quickly, while later varieties are still in the green fruit stage and starting to move toward color. The bad is that disease symptoms and insect pressure are starting to rise. With last week’s heat, direct sun, and scattered heavy rain in some locations, harvest-ready fruit took a hit. Some ripe berries are showing signs of sunburn. Other areas with heavy rain are showing signs of rain damage on mature fruit and are developing soft spots across the field. Those soft spots are a perfect entry point for fruit rots, with Botrytis being the main concern right now. Leaf spot has also been identified in western Massachusetts, but at this point it appears to be isolated.
The main message for strawberries is to keep picking as fast as possible. Do not let ripe fruit sit in the field, especially on softer varieties, or any blocks that are already showing rain injury. Remove overripe or damaged fruit when practical, keep harvest intervals tight, and cool fruit quickly after picking. Irrigate as needed during hot weather, but try to keep fruit and foliage dry whenever possible. Good luck figuring that one out.
Blueberries are coming along nicely. Most varieties are now in the green fruit stage, and new shoot growth is near the peak of the first major flush of the season. Expect one, and possibly two, more periods of rapid shoot growth before the season is over. As mentioned above, growers should be finishing up their final fertilizer applications over the next couple of weeks. Overall, the crop looks good in many locations, but it is still too early to call the season. We will know more once fruit begins to size and color.
Some growers may be seeing smaller berry size on certain bushes or individual canes. If small fruit is showing up on the same older cane year after year, flag that cane now and plan to remove it during dormant pruning. Once a cane has been cropped and pruned repeatedly for five or more years, it often begins to decline and should be removed to make room for younger, stronger wood. Iron deficiency is also starting to appear in some blocks as the season progresses. This is often tied to soil pH or nutrient availability, so the best first step is to get a soil test and go from there. If you are seeing unusual yellowing, weak growth, or uneven symptoms across the field, contact me.
Brambles are also moving along well. Raspberries, and blackberries are in bloom to early green fruit depending on site and variety. Floricanes are still pushing strong vegetative growth and should be monitored for cane density, weeds, and overall vigor. Primocanes are at the green fruit stage. Disease pressure can increase quickly after wet weather, so keep an eye out for cane diseases, Botrytis on blossoms and young fruit, and any early signs of orange rust or other foliar issues. Spotted wing drosophila numbers have dropped sharply in some locations following the recent heat, but do not let that fool you. This is likely a temporary break. Keep traps out and continue monitoring as fruit begins to color.
Grapes are still in rapid shoot growth, with some early varieties already setting fruit while others are still in bloom. Shoot thinning and canopy management should remain a priority. Open canopies will improve spray coverage, airflow, and disease management as we move through bloom and early fruit set. This is still an important window for black rot, powdery mildew, downy mildew, and Phomopsis management, especially after wet weather. Spotted lanternfly nymphs have been observed, but so far populations are being managed without major changes to our pesticide program. The biggest addition this year has been early scouting and egg mass scraping. Keep scouting vines, posts, trunks, and nearby tree-of-heaven, and report any new or increasing populations.
Be safe out there.
--Written by J. Galvan, UMass Fruit Program
Tomato Pollination Time
--Written by Judson Reid, Extension Vegetable Specialist, CCE Cornell Vegetable Program. Originally published in Cornell VegEdge, Vol. 22, Iss. 07, June 3, 2026.
Keeping pollinators present in tomato plantings is important for both high tunnel and greenhouse tomato crops. Healthy flowers and healthy pollinator populations increase quality, yield and profitability.
Tomato flowers are open from 1 to 3 days, during which time the pollen produced in the anthers (the longer portion of the flower) must move to the stigma and down to the ovary at the base of the flower. The complete pollination of the ovary results in larger, round tomatoes. Without complete pollination there can be small, misshapen fruit, and/or catfacing (scars resembling zippers).
Pollen is most viable for fertilization at temperatures of 60-85°F and relative humidity of 50-80%. It is possible, and common, that flowers are pollinated by wind or shaking. However, pollinating insects such as bumblebees physically move pollen from one flower to another. When they grasp the flower they give a quick ‘buzz’ which shakes pollen they carry from one flower to another leading to abundant pollination. Their flights align with the conditions of optimal pollen viability.
Bumblebees are available from commercial insectaries and are contained within cardboard boxes that have adjustable entrance and exit holes. Hives come in various sizes with different number and sizes of bees. It is important to consult directly with the insectary to share the plant population so they can ship the right sized hive. If the hive is not the right size for the greenhouse it can be worse than not having pollinators. Why?
Bumblebees will visit a flower 1-5 times while it is open. However, if there are too few flowers and too many bees, they will visit the flower too often, which can lead to a damaged flower that will turn black and fall off. In these cases, the hive is too large, too aggressive and/or there are not enough flowers available for the bumblebees.
For this reason, we recommend monitoring flowers daily, particularly in the first few weeks of having a hive in a greenhouse. If the ratio of bees to flowers is optimal, pollinated flowers with show small ‘grab-marks’ that the bees leave behind on the anthers. If they visit too often these marks will be dark, and eventually the center of the flower will turn black.
If flowers are becoming discolored or dropping due to excess pollination growers can manipulate the adjustable exit and entrance holes on the hive box to restrict flight times. Some growers benefit from the presence of hanging ornamentals to spread out the bee population. During warmer weather open sides and vents will allow bees to forage outside the greenhouse.
Potato Leafhopper Active in Potato, Eggplant, Beans
Potato leafhopper (PLH) adults are active in MA now, on potatoes, eggplants, and beans. In about 7-10 days we should begin seeing the immature “nymph” stage crawling side-to-side on the undersides of leaves. Because even low numbers of adults or nymphs cause injury that reduces yield, it is important to protect plants before adult numbers are high and before nymphs build up. Left uncontrolled, PLH populations will continue to grow rapidly. Plant injury and yield loss can be significant. In potato, yield loss occurs even before the development of obvious symptoms. Green beans are also very susceptible, especially when they are infested prior to flowering.
Identification
Adults are about 1/4-inch long, light yellow-green, and fly up from foliage when it is disturbed or shaken—they look like tiny green sparks flying away from the plants. PLH overwinters in the southern US and the adults move north annually. Once adults arrive, they lay eggs in the veins and petioles of leaves. Nymphs hatch after about 10 days; they are tiny, light green, wedge-shaped and very fast-moving. They like to hang out on the underside of leaves and tend to move sideways, in a crab-like fashion. Presence of nymphs indicates an established population.
Damage
Adults and nymphs feed by inserting their needle-like beak into the plant and sucking out sap. They also inject a toxin into the plant, blocking conductive tissues and causing yellowing, browning, and curling of leaves. This condiition is known as "hopperburn". In potato, leaf margins turn brown and brittle first, followed by death of entire leaves. In eggplant, leaf margins and tips turn yellow and curl up. Feeding can reduce yield before damage is visible. Damage can be severe on early-season and red varieties of potato, as well as in green beans, eggplant, and raspberries. Long-season cultivars tend to be more tolerant. Beans are more susceptible when they are young than at later stages. Field crops such as alfalfa, clover, soybean, sunflower, and tobacco are also hosts and populations can soar in vegetable crops when nearby field crops are mowed.
Cultural Controls
Row cover can be used to delay PLH infestation in snap beans and eggplant until flowering, when plants are less susceptible to damage. Crop rotation is of little use for PLH control, as the adults migrate north from southern overwintering sites annually.
Scouting and Thresholds
It is difficult to count adults since they fly quickly when foliage is shaken or disturbed. Sweep nets can be used to detect adults. Once nymphs develop, they can also be monitored by visually inspecting lower leaf surfaces on lower-canopy leaves.
Recommended treatment thresholds for susceptible crops are:
Potatoes: 1 adult per sweep net or 1 adult per plant when plant is shaken, or 15 nymphs per 30 leaves
Beans: 2 adults per row foot (seedlings), or 5 adults per row foot or 1 nymph per leaflet (third-leaf to bud stage)
Eggplant: 1.5 adults or large nymphs per leaf
Chemical Control
Don't wait for PLH numbers to build up to begin chemical control. In potato and eggplant, some materials registered for Colorado potato beetle (CPB) adults will also control leafhopper, including neonicotinoid foliar sprays such as Admire Pro or Assail. These and several other carbamate, pyrethroid, and organophosphate products are also registered for leafhopper control—refer to the New England Vegetable Management Guide for registered products in potato, eggplant, and beans.
The newly registered products Zivalgo and Incipio, which use the active ingredient isocycloseram (marketed as Plinazolin), are also labeled for potato leafhopper control, in potato (Zivalgo) and eggplant (Incipio). Isocycloseram 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. The labels for both Zivalgo and Incipio include 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.
For organic growers, PyGanic EC5.0 (pyrethrin) has been shown to be the most effective product for reducing leafhopper numbers and damage. Pyrethrin must contact the leafhoppers to be effective and breaks down quickly in sunlight, so good coverage is important, especially of the leaf underside where nymphs are found. Spraying late in the day or in the evening may provide better control than spraying early in the morning. Products containing azadiractin have also demonstrated efficacy against leafhoppers (especially in fruit systems) and could be used in tank-mixes or in rotation with Pyganic EC5.0.
Pollinators and Other Beneficials
Although bees do not forage extensively in beans or potatoes, they may be active in the field when these crops, or the weeds within the crop fields, are flowering. During that time, selection of products with lower toxicity to bees is advised. Look for toxicity information on the label, and also in the New England Vegetable Management Guide Table 26, and in the products listed for each crop and pest.
For conservation of both native pollinators and honeybees, control weeds in the crop and avoid drift onto flowering borders or crops. However, encouraging some flowering areas in the margins is good for supporting pollinators before and after crops bloom. These can also be a nursery and refuge for beneficial predators and parasites of insect pests.
—UMass Extension Vegetable Program
Events
All About Peppers – Twilight Meeting at Kitchen Garden Farm
When: Tuesday, July 21, 2026, 4-6 pm, followed by refreshments
Where: Kitchen Garden Farm, 131 S. Silver Lane, Sunderland, MA 01375
Registration: Free! Please register in advance. Click here to register.
Kitchen Garden Farm is a 65-acre specialty vegetable operation and value added business in Sunderland, MA. The farm grows a variety of crops to process into a line of hot sauces, salsas, pickles, and dried spices/herbs, including peppers, tomatoes, onions, cauliflower, celery, carrots, oregano, thyme, sage, as well as a diverse array of crops for niche regional and local wholesale markets.
This meeting will focus on their pepper production and some of their related challenges, including Phytophthora and pepper maggot, and work they're doing in collaboration with UMass Extension to try to improve management. The farmers will also share their experiences with learning about the risk management options available to their farm through crop insurance and the FSA's Non-Insured Disaster Assistance program (NAP).
41st Massachusetts Tomato Contest
When: Thursday, August 20
Where: Boston Public Market
Please join MDAR and the New England Vegetable and Berry Growers Association for the 41st Massachusetts Tomato Contest! Tomatoes will be judged by a panel of experts on flavor, firmness/slicing quality, exterior color, and shape. Always a lively and fun event, the day is designed to increase awareness of locally grown produce.
Open to commercial farmers in Massachusetts, growers can bring tomatoes to the market between 8:45am and 10:45am on August 20 or drop their entries off with a registration form at one of the regional drop-off locations on Wednesday, August 19. Drop off locations include sites in South Deerfield, Southboro, North Easton and West Newbury. These tomatoes will be brought to Boston on Thursday.
Details, including drop off locations, contest criteria, and registration form here. *Be sure to include the registration form with all entries.
The 41st Tomato Contest is sponsored by the MDAR and New England Vegetable and Berry Growers Association, in cooperation with the Boston Public Market. Please consider participating to showcase one of the season’s most anticipated crops!
Questions? Contact Rose Arruda, rose[dot]arruda[at]mass[dot]gov (rose[dot]arruda[at]mass[dot]gov).
Save the Dates!
- 2026 MA Fruit Growers' Association Summer Meeting: Wednesday, July 15, 9:30am-2:30pm, UMass Cold Spring Orchard, Belchertown, MA
- UMass Agronomy Farm Research Field Day: Wednesday, August 5, 9:30am-1pm, South Deerfield, MA
- Food Safety Farm Tour at Red Shirt Farm: Monday, August 31, Lanesborough, MA
- Temporary Fence Installation & Maintenance: Thursday, September 17, 5-7pm, Heart Beets Farm, Berkley, MA
