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Crop Conditions
The general gist we’re getting from folks is that things are growing slowly and crops are behind schedule. We may not have much local corn for the Fourth of July, but while sweet corn plantings tend to be behind where they were at this point last year, we have heard that growers are seeing less caterpillar damage.
Summer squash and cukes are filling market bins now, along with Napa cabbage, green cabbage, and kohlrabi. The sugar snap peas that made it through the spring are filling baskets too, and there’s rhubarb to go with the last wave of strawberries. Blueberry PYOs are opening up.
There are also so many gorgeous flowers out there! The Veg Team’s Hannah Whitehead is continuing her work developing resources for cut flower growers in the Northeast. Last night she joined EMass CRAFT for a cut flower field walk at Clark Farm in Carlisle, Ma. It was great to see so many people come out! We learned about how Clark Farm likes to focus on dried flowers since they don’t need to be harvested in the morning (which would conflict with the main vegetable harvesting window) and because dried wreath arrangements provide an off-season source of income in the winter. We just added save-the-dates for 2 more flower-related programs for this fall—see the events section in this issue, below. And if you want to catch up on past programs, our cut flower webinar series is posted on our YouTube channel.
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 with home gardening and homesteading questions, at greeninfo[at]umext[dot]umass[dot]edu (greeninfo[at]umext[dot]umass[dot]edu).
Pest Alerts
Alliums
Onion thrips damage is now being seen in some fields. Frequent rain can wash thrips off of leaves, resulting in lower thrips pressure, but warm temperatures speed up their development. The threshold for insecticide application is 1-3 thrips/leaf. Organic growers should use the lower 1 thrips/leaf threshold, as OMRI-listed materials are less effective. See the appropriate crop insect control section of the New England Vegetable Management Guide for labeled materials.
Beans
Mexican bean beetle (MBB) adults, eggs, and larvae were present in a bean field in Hampshire Co. this week. Adults and larvae feed on legume foliage and can eventually skeletonize leaves. There are several generations per year. This pest can be controlled using the parasitic wasp biocontrol Pediobius faveolatus. The wasp lays its eggs in MBB larvae and the developing wasp larva feeds on the MBB larva from inside. Ideally, you will only need to release Pediobius in the first MBB generation—the wasps that hatch from the parasitized larvae will go on to control the next generation of larvae. Pediobius can be ordered from the NJ Department of Ag. Scout your beans and call to order the Pediobius immediately if you see larvae. If you don’t see larvae yet, flag an egg cluster and check it every few days to monitor when it hatches, then call to order the Pediobius. The wasp can be ordered as live adults, which are ready to parasitize when they are released, or as mummies with developing larvae inside. Wasps will emerge from the mummies within a few days.
Brassicas
Alternaria infections are now present in some brassica crops, likely due to the wet weather. These fungal pathogens can cause damage to seedlings, leaves, and heads, reducing crop quality and yield. The pathogens require long periods of leaf wetness to infect and so are favored by rainy periods, overhead irrigation, and overnight dew, common in the fall. Increasing plant spacing and controlling weeds can help speed drying. Once the disease is present, regular sprays can reduce severity and are especially prudent with heading crops like broccoli and cauliflower. See the New England Vegetable Management Guide for current fungicide recommendations.
Cucurbits
Cucurbit downy mildew was reported this week on cucumbers in Michigan and Pennsylvania. Growers in MA should begin scouting cucumbers and cantaloupes now and have a spray program plan. See the article in this issue for more information including the most effective fungicide spray programs.
Squash bug: We are seeing more adults and egg masses in cucurbit crops this week. We have not yet encountered nymphs in the field, but we have seen them on cucumbers in high tunnels where they are expected to develop more quickly. If you have reached the threshold of one egg mass per plant, scout regularly and treat with an insecticide once nymphs begin to emerge. See the article in this issue for more information.
Squash vine borer (SVB) numbers are increasing in areas where their populations have already been building up this year, with trap captures at some sites reaching treatment thresholds (Table 1). Make 2-4 weekly applications if more than 5 moths per week are captured. Timing is very important. Treat base of stems thoroughly to target hatching larvae. Some selective materials used for other caterpillars in squash, such as spinosyns and Bacillus thuringiensis aizawi, have demonstrated efficacy in trials.
| Trap Location | SVB Count |
|---|---|
| Sharon | 11 |
| Lexington | 0 |
| Leominster | 0 |
| Whately | 6 |
| Westhampton | 20 |
| Spray thresholds: 5 moths/night for bush-type cucurbits, or 12 moths/night for vining cucurbits. | |
Sweet corn
European corn borer (ECB): Moth numbers are low across the board as the first flight wraps up, with most growers reporting relatively little ECB damage in their sweet corn this year. The 2nd flight starts at 1400 GDDs, which should be in the next few weeks, but caterpillars are still feeding in tassels and ears. A good time to apply a pesticide is when tassels have just fully emerged, to catch the caterpillars before they migrate down from the whorl and tassels into the ears. Treat if 12% of plants are infested.
Corn earworm (CEW): Trap counts have continued to decline in most areas, with captures in some locations not warranting any spray. If CEW trap captures are below 1.4/week, scout silking corn for ECB caterpillars and treat at the 12% threshold.
Fall armyworm (FAW): One moth was captured in New Hampshire this week, but we have yet to see this pest in Massachusetts this year. More FAW pheromone traps will be set up as we approach the point in the season when we typically start seeing this pest.
| GDDs (base 50°F) | Trap Location | ECB NY (2) | ECB IA (1) | FAW | CEW | CEW Spray Interval |
| Western MA | ||||||
| 1040 | Northampton | 2 | 1 | - | 1.5 | 6 days |
| 1065 | Whately | 0 | 0 | 0 | 1.5 | 6 days |
| 958 | Southwick | 6 | 1 | 0 | 2 | 6 days |
| Feeding Hills | 1 | 0 | 0 | 3 | 5 days | |
| Central MA | ||||||
| 982 | Leominster | 1 | 0 | - | 5 | 5 days |
| 1021 | North Grafton | 0 | 0 | 0 | 2 | 6 days |
| 993 | Bolton | 0 | 0 | - | 2 | 6 days |
| - | Townsend | 2 | 0 | 0 | 1 | no spray |
| Eastern MA | ||||||
| 1018 | Concord | 0 | 0 | 0 | 2 | 6 days |
| 999 | Millis | 3 | 5 | - | - | N/A |
| Sharon | 0 | 0 | - | 0 | no spray | |
| - | Sherborn | 8 | 0 | 0 | 4 | 5 days |
| 1090 | Seekonk | 0 | 0 | 0 | 1 | no spray |
| Swansea | 0 | 0 | 0 | 13 | 4 days | |
N/A - no data available - no numbers reported for this trap * If CEW trap captures are below 1.4 moths/week, scout block for ECB and FAW caterpillars and make a pesticide application if 12% of plants in a 50-plant sample are infested. | ||||||
| Moths/night | Moths/week | Spray interval |
|---|---|---|
| 0 - 0.2 | 0 - 1.4 | no spray |
| 0.2 - 0.5 | 1.4 - 3.5 | 6 days |
| 0.5 - 1 | 3.5 - 7 | 5 days |
| 1 - 13 | 7 - 91 | 4 days |
| Over 13 | Over 91 | 3 days |
Multiple/Miscellaneous Crops
Potato leafhopper nymphs and adults are increasing in number, and we are seeing the resulting hopperburn in potatoes, beans, eggplant, and even basil. Typical symptoms of hopperburn include curling, yellowing, and browning of leaves, especially on leaf tips and margins. Adults fly quickly when disturbed but can be counted using a sweep net. Nymphs can be monitored by inspecting the undersides of leaves. In potatoes, treat at a threshold of 1 adult per plant or net sweep, or 15 nymphs per 30 leaves. For seedling beans, use a threshold of 2 adults per row foot. For beans in the 3rd -leaf to bud stage, use a threshold of 5 adults per row foot or 1 nymph per leaflet. In eggplant, use a threshold of 1.5 adults or large nymphs per leaf. See the potato leafhopper article from our June 20th issue for more information.
Pendimethalin Herbicide Damage
This week we noticed what we believe to be pendimethalin damage in dry bulb onions. Pendimethalin, commonly sold as Prowl H2O or Satellite HydroCap, is a pre-emergent herbicide, meaning it kills weeds as they germinate from seeds and does not control emerged weeds. It is in the same group (group 3) as trifluralin and ethalfluralin, which are the dinitroanilines. Pendimethalin is absorbed by roots just emerging from the seed and does not translocate further through the plant. At the root tips, it disrupts cell mitosis (the process of cell division) by inhibiting the production of microtubules, which are responsible for pulling replicated chromosomes apart. Because cell mitosis is disrupted in the root tips, you can usually see root clubbing in plants that are damaged by pendimethalin.
There are several pendimethalin products labelled for use in onions in MA, but they all have very specific application instructions to prevent crop damage because onions can be susceptible depending on their growth stage and the amount of active ingredient they are subjected to. You will notice on the label of any pendimethalin product that there are different directions for applications to onions in muck soils. Muck soils are made from decaying plant material and therefore have extremely high organic matter content (over 10%), which binds to the herbicide. I don’t think any farms in Massachusetts are growing crops in muck soils so likely these instructions don’t apply to you. Make sure to follow the directions for applications to mineral soils.
For direct-seeded onions in mineral soils, pendimethalin products can be band-applied between the rows, staying away from the soil where onions will be seeded. You can go back and band-apply pendimethalin over the top of the onion rows later, but not until the onion flag leaf has emerged. Be sure to only apply pendimethalin once over the whole field, but you can do the between-row soils first and the within-row soils later, after the onions have emerged. The rate you apply will be based on soil texture, so make sure to match the application rate to your soil. See the article on pre-emergent herbicides from the April issue of Veg Notes for considerations for applying pre-emergent herbicides.
Unfortunately, rainfall and temperature, which are out of your control, can also affect how much pendimethalin will be available. The label warns that applications made before the onion loop stage can cause serious crop injury if it is followed by more than ½ inch of water. This year, it is possible that the heavy spring rainfall may have moved the pendimethalin too deep into the soil profile, causing damage as the direct-seeded dry bulb onions were germinating.
Early season weed management in direct-seeded onions grown in mineral soils is very tricky because all pre-emergent herbicides except bensulide (Prefar 4E) need to be applied after the onions have true leaves.
--Written by Maria Gannett, UMass Extension Weeds Specialist
Squash Bugs Out Now
Squash bugs are a perennial problem in cucurbit crops, causing leaf dieback, Anasa wilt, and physical damage to squash fruit. Nymphs are emerging now, so it’s a good time to start including them in your pest management plan or taking note of their presence and making a plan for next year.
Life stages and identification
Squash bugs are a type of true bug, a group that also includes other pests like the native brown stink bug and brown marmorated stink bug, as well as beneficial insects like the spined soldier bug. Adults are 0.5-0.75 inches long, flattened, and grayish-brown, and can be differentiated from stink bugs and spined soldier bugs by their more elongated body shape and rounded shoulders. The edge of the abdomen is marked with alternating gold and brown patches. Adults frequently take shelter beneath debris in the field at night, and it’s common to see many bugs congregated beneath a squash fruit in the field. Adults are long-lived and lay eggs over several weeks. A single female can lay up to 250 yellow- to bronze-colored eggs, usually in an orderly cluster in the junction of leaf veins on the underside of leaves, which hatch in 7-10 days in summer conditions. Nymphs are wingless and usually found in groups. They are light green when small, with a dark-colored head and legs, but become darker gray and more solitary as they grow and molt through 5 nymphal stages. There is one generation per year in the Northeast, and the complete life cycle requires 6-8 weeks.
Host crops and damage
The most susceptible and attractive crops are yellow summer squash, zucchini, and pumpkin (Cucurbita pepo) as well as C. maxima crops (e.g. Hubbard squash). Watermelon, cucumber, muskmelon, and butternut squash resist damage and provide poor food quality for adults and nymphs. Resistant varieties also include sweet cheese pumpkins (C. moshata) and royal acorn squash (C. pepo). Both adults and nymphs feed by sucking sap from plant tissue using their beak-like mouthparts. Adult feeding on seedlings can cause wilting of the whole plant. Places on the leaves where the bugs feed develop small, yellow specks that eventually turn brown due to a toxin released by the bug during feeding. High densities and intensive feeding cause foliage to wilt, turn black and die in a condition known as “Anasa wilt”. Squash bugs also feed on the fruit, causing scarring that can make the fruit unmarketable.
Squash bugs may also vector the bacterium Serratia marcescens, which causes the disease yellow vine decline. This disease is reported intermittently in New England; it is not thought to be widespread, but it was found in MA in 2003 and was again confirmed from one site in CT in 2020. The bacterium is introduced into a cucurbit plant by squash bug mouthparts and enters the plant’s phloem sap. Symptoms of yellow vine decline include a general yellowing of the entire vine within a two- to three-day period. Infected plants usually collapse completely approximately 10 to 14 days before the fruit matures. Plants infested with squash vine borer can display similar symptoms—leaf yellowing, wilt, lack of vigor—but will have an entry hole in the stem where the borer entered, usually accompanied by lots of sawdust-like frass. If you are seeing symptoms that you suspect could be yellow vine decline in your cucurbit crops, let us know at umassveg[at]umass[dot]edu or (413) 577-3976.
Cultural Control
If possible, rotate cucurbit crops between fields as far apart as possible. Placing row covers over the young crop prevents adult access until blooming, when covers must be removed. Natural enemies of the squash bug include the tachinid fly Trichopoda pennipes which is a parasitoid that attacks nymphs and adults and can commonly be found in cucurbit fields at this time of year, and several wasps that parasitize eggs (Hymenoptera: Encyrtidae and Scelionidae). Squash bugs like sheltered hiding places, so keep field edges mowed and free of debris to reduce overwintering sites. Plastic and straw mulch and reduced tillage systems encourage higher populations, probably by providing good hiding places. In small plantings, boards can be used to attract adults seeking a protected hiding place; check in the morning or evening and spray with insecticide or capture and squish. Remove crop residues and/or till field immediately after harvest to kill adults before they move to field edges seeking shelter. Research has shown that squash bugs are highly attracted to Blue Hubbard squash, which can be used effectively as a trap crop planted earlier in the season along field edges. The trap crop must receive an insecticide application or be mechanically destroyed before eggs hatch.
Scouting and Chemical Control
Scout plants from seedling to vining/flowering stage to detect adults as well as eggs and nymphs. After flowering, thresholds are based on egg masses and young nymphs, but also note adults and large nymphs while scouting.
There are two key windows for control:
- Target adults on young plants (before flowering or vining). An insecticide application made when adults are colonizing plants in June will prevent subsequent egg and larval populations. Coverage is easier at this time, and broad-spectrum pyrethroids (e.g. bifenthrin, lambda-cyhalothrin, permethrin) or carbaryl, which are reported to be effective on adults at this stage, can be used without risk to bees on the crop. OMRI-approved pyrethrin products are available (e.g. PyGanic). The threshold for targeting adults has been determined for watermelon crops at an average of 1 adult per plant (Dogramaci et al. 2006), but in more susceptible crops such as summer squash and zucchini, it might be appropriate to use a lower threshold (e.g. 1 adult per 2 or more plants). Aim for coverage of underside of leaves and stems where bugs hide. Systemic furrow, drip, or seed treatments and sprays for cucumber beetle at the seedling stage may also control colonizing squash bug adults.
- Target smaller nymphs on flowering plants. Scout for egg masses and note the first emergence of nymphs. The threshold is reached at an average of 1 egg mass per plant and when the first nymphs are seen. Good coverage of undersides of leaves is needed. For newly laid eggs and nymphs, consider a foliar application of acetamiprid (Assail 30 SG) which has moderate toxicity to bees (lower than other neonicotinoids). Adults and larger nymphs are more difficult to control, partly because they hide in the lower canopy and near the soil. An organic option for nymphs is a mixture of pyrethrin (a contact toxin) and azadiractin (an insect growth regulator, derived from neem). This would be gentler on bees than a high rate of pyrethrin alone and would include two modes of action. Insect growth regulators work to disrupt the molting process, so they are useful only on immature stages. Treat late in the day when the flowers are closed to reduce risk to bees.
Take note of re-entry and pre-harvest intervals of materials used on summer squash and zucchini that are being harvested frequently.
For more information on rates and products for squash bug control, see the Cucumber, Muskmelon, and Watermelon insect section and the Pumpkin, Squash, and Gourds insect section of the New England Vegetable Management Guide.
--UMass Vegetable Program
Managing Cucurbit Downy and Powdery Mildew
--written by Meg McGrath.and updated for 2025 by UMass Extension Vegetable Program.
For many years, we’ve published the results and recommendations from Meg McGrath’s annual bioassays and fungicide trials for resistance development in the cucurbit downy and powdery mildew pathogens. Meg retired from her position as plant pathologist at the Cornell Extension Long Island Horticultural Research and Extension Center (LIHREC) in 2023. She and her work will be missed by all her colleagues and the many growers she’s helped over the years. Her fact sheets and other resources on downy and powdery mildews are still available on the Cornell Extension website, and you can find the full collection of resources from the LIHREC here. Below are Meg’s most recent downy and powdery recommendations, from 2022, with updates for 2025 by Sue Scheufele.
Cucurbit powdery mildew (PM) is a fungal disease of cucurbit crops that begins developing in New England in mid-summer every year. The fungus produces round patches of powdery white sporulation on the tops and bottoms of cucurbit leaves and severe infections will lead to extensive defoliation, reducing yield. The similarly named cucurbit downy mildew (DM) is a different pathogen; powdery mildew is a true fungus, whereas downy mildew is a fungal-like organism called an oomycete. Downy mildew spores land on host leaves, infect and grow within the leaf, and produce fuzzy gray sporulation only on the undersides of leaves. Lesions are angular because the pathogen cannot grow across the leaf veins. Both pathogens can be transmitted over long distances by wind. Neither downy nor powdery mildew infects cucurbit fruit directly; however, leaves infected by either pathogen will die prematurely, resulting in significant yield losses and decreased fruit quality. While several of the management recommendations are the same for preventing disease spread by these organisms, the distinction is important because fungicides that control powdery mildew will not control downy mildew, and vice versa.
Also, downy mildew is caused by an obligate parasite, meaning that it must have a living host to survive. For that reason, it does not overwinter in the Northeast, where winter temperatures kill cucurbit crops. Instead, it travels north from warmer regions on storms as the season progresses. The powdery mildew pathogen, on the other hand, can produce a sexual spore in the fall that enables it to survive over winter in New England.
Powdery & Downy Mildew Management
The most important components of an effective management program for powdery and downy mildews are resistant varieties and properly timed fungicides. Both diseases develop best on the undersides of leaves, so mobile (or translaminar) fungicides are needed to achieve successful control. Resistance to certain fungicides is widespread for both pathogens; fungicide recommendations change as new resistance develops or as new products are released. Always implement a resistance management program; do not wait until there is a problem. The goal is to delay development of resistance, not manage resistant strains afterwards. Again, because downy mildew is an oomycete and not a true fungus, targeted fungicides that control powdery mildew will not control downy mildew, and vice versa. Phytophthora blight, also caused by an oomycete, will usually also be controlled by fungicides that are effective for downy mildew.
- Select resistant varieties. There are many PM-resistant varieties of many types of cucurbits available, and DM-resistant cucumber varieties available.
- Inspect crops routinely for symptoms of both powdery and downy mildew, beginning at the start of crop development. Scouting routinely for early symptoms is important to ensure targeted fungicides are applied starting at the onset of disease development. Click here to view images of symptoms of downy and powdery mildews.
- Monitoring disease outbreaks is important for determining when fungicide applications are warranted. Cucurbit plants are susceptible to downy mildew from emergence; however, this disease usually does not start to develop in the Northeast until later in crop development when the pathogen is dispersed by wind into the region. The pathogen is thought to only be able to survive over winter in southern Florida, and from there spreads northward. There has been no evidence that the pathogen is surviving between growing seasons where winter temperatures kill cucurbit crops (outdoors above the 30th latitude). Tracking occurrences and paying attention to forecasted storms can alert you to when protectant and/or targeted sprays are warranted. Sign up to receive alerts about downy mildew occurrence and routinely check the Cucurbit Downy Mildew mapping site to track where the disease is occurring and what crops are affected or read our weekly Pest Alerts for a summary update of powdery and downy mildew outbreak status.
- Make preventive and targeted pesticide applications based on forecast and reported risk. For both powdery and downy mildews, apply protectant fungicides weekly before symptoms develop in your crop. For powdery mildew, begin these preventive sprays when crops start producing fruit or when powdery mildew is reported in the area. For downy mildew, begin when the disease has been reported in the area and weather forecasts indicate that storms may be moving in your direction. When you first detect PM in your crop by scouting, add a PM-targeted material. When the DM risk level increases in your area, add a DM-targeted material. Targeted materials will be different for PM (a true fungus) and DM (an oomycete). Rotate between FRAC groups for the targeted materials.
- Add new fungicides to the program when they become available; substitute new for older products if they are in the same FRAC group, unless efficacy data indicate they are not as effective.
Protectant materials include:
- Sulfur: very effective, inexpensive product for PM. Has no efficacy for DM or other diseases.
- Oils: Effective for PM but not DM. Several botanical and mineral oils are available (search Table 24 in the New England Vegetable Management Guide for “oil”).
- Chlorothalonil and copper: Effective against both PM and DM. Copper is less effective against DM than chlorothalonil or mancozeb but is effective against bacterial diseases and OMRI-approved formulations are available.
- Mancozeb: Recommended when only DM is occurring.
Powdery mildew fungicides recommendations:
When powdery mildew is present, apply targeted fungicides weekly with contact fungicides (sulfur, chlorothalonil, and oil are more effective than copper) and alternate amongst available chemistry based on FRAC Group code. It is prudent to decide now what products to use each week and have a plan in place ready to implement. Use the highest label rates to control moderately resistant isolates if present.
- Vivando (FRAC 50) can be applied up to 3 times with no more than 2 sequential applications. It is a good choice for the last application considering the long residual activity observed in the 2018 fungicide evaluation; it is also recommended to be used at other times during the season.
- DMI fungicides (FRAC 3) are also a good choice in the program, particularly for the first application. Proline is the most effective. It is also labeled for Fusarium. Crop limit is 2 applications. Procure is also very effective. It can be applied 3 times, or 4 times to direct-seeded crops when the intermediate rate is used. Trionic is a newer product, which may be more effective, but efficacy data is lacking.
- Gatten (FRAC U13) was introduced in 2018, and so is a relatively new chemistry. REI is 12 hr. PHI is 0 days. It can be applied 5 times. Activity is limited to powdery mildew. It was as effective as Vivando for managing powdery mildew on lower leaf surfaces in a fungicide evaluation conducted at LIHREC in 2019 but not in 2018.
- Luna fungicides* contain fluopyram (FRAC 7) pre-mixed with other active ingredients to yield a somewhat confusing proliferation of magical sounding products each labeled for a different set of diseases and crops – Luna Sensation (+ FRAC 3), Luna Experience (+ FRAC 11), Luna Flex (+ FRAC 3). Luna Flex has the widest range of cucurbit crops and includes a DMI (recommended) pre-mix as opposed to a QOI (not recommended due to resistance) and is therefore the recommended choice for cucurbit PM (Luna Sensation is only labeled for watermelon). Luna Flex has a 12-hour REI and a 0-day PHI and can be used twice per crop per season. Velum Prime is another fluopyram product that can be used through drip chemigation.
- Miravis Prime* (FRAC 7+12) has a 12-hour REI and a 0-day PHI and can be used twice per crop per season.
- Orondis Opti* (FRAC 49 + M05) is a pre-mix of a new chemical, oxathiapiprolin, with the protectant fungicide chlorothalonil. Use Orondis Opti (or any other FRAC 49-containing product) in no more than 33% of the applications, or a maximum of 4 applications per planting, whichever is fewer. Orondis Opti has a 12-hour REI and a 0-day PHI.
Quintec, Torino, Endura, and QoI fungicides (FRAC 3) are not recommended due to resistance.
*Newer products that are less likely to have resistance since they have not been recommended for as long
Example recommended alternations of targeted fungicides:
- 6 applications: Orondis Opti, Vivando, Proline, Vivando, Luna Flex, Vivando
- 6 applications: Proline, Vivando, Luna Flex, Vivando, Procure, Vivando
- 8 applications: Orondis Opti, Proline, Vivando, Luna Flex, Proline, Orondis Opti, Vivando, Luna Flex
Assess control achieved on the underside of leaves toward the end of the season when there is still a good canopy.
Downy mildew fungicide recommendations:
There is more information available about each material, including maximum number of sprays and application recommendations, available at Dr. McGrath’s Cucurbit Downy Mildew Management website.
Targeted fungicides listed in alphabetical order below were effective in 2024 research trials conducted by Mary Hausbeck in Michigan. These should be mixed with a protectant fungicide to delay resistance development unless one is already present as a pre-mix, as described below.
Elumin + chlorothalonil or mancozeb
(FRAC 22): 12-hour REI and 2-day PHIOmega (Orbus) + chlorothalonil or mancozeb
(FRAC 29): 12-hour REI and 30-day PHI for melons and 7-day REI for cucumbers and squash.*Orondis Opti (chlorothalonil is part of the premix, additional chlorothalonil is suggested; see label for maximum chlorothalonil rates).
(FRAC 49 + M05): 12-hour REI and 0-day PHIPrevicur Flex + chlorothalonil or mancozeb
(FRAC 28): 12-hour REI and 2-day PHI. Can be applied foliar or via drip chemigation.*Ranman + chlorothalonil or mancozeb
(FRAC 21): 12-hour REI and 0-day PHI in the field and 1-day PHI in the greenhouse.Zampro + chlorothalonil or mancozeb.
(FRAC 40 + 45): 12-hour REI and 0-day PHI
*Products considered to be especially effective in Michigan based on yearly, season-long field trials.*
Other labeled products may be less effective based on recent trials:
- Zing! or Gavel (FRAC 22): 12-hour REI and 2-day PHI
- Curzate, or Tanos (FRAC 27): 12-hour REI and 3-day PHI
*Newer products that are less likely to have resistance since they have not been recommended for as long
Targeted fungicides below are not recommended because resistance is known:
- Presidio (43)
- Revus and Forum (40)
Garlic Harvest, Curing, and Storage
Garlic harvest is a big, landmark summer task that usually occurs around mid- to late July. As you start to prepare for garlic harvest, here are some tips from Crystal Stewart-Courtens of Cornell Cooperative Extension on determining ideal harvest timing: heads should be left in the ground as long as possible to attain maximum bulb size (which doubles in the last stage of growth), but not so long that the cloves begin to separate, as overripe bulbs sell and store poorly. Harvest when leaves begin to turn yellow, but when about 60% are still green—one rule of thumb is to harvest when there are a minimum of three leaves left that have not begun to brown at the tips. Check bulbs by cutting through the head sideways to see if the cloves fill the wrappers – if they are loose within the wrappers, the garlic has a little ways to grow. A little of the outermost wrapper may have started to discolor at this point. Harvest before the cloves start to separate from each other within the bulb, which can happen relatively quickly, especially in a wet year. It is better to harvest too early than too late. Find more harvest and storage tips from Crystal in last year's June 13th issue of Veg Notes.
Use hand tools to loosen soil under the bulbs or a mechanical harvester to undercut the bed. Pulling bulbs out when they are tight in the ground can open wounds at the stem-bulb junction and allow for fungal infections. Fresh bulbs bruise easily and these wounds can also encourage infection. Don’t knock off dirt by banging bulbs against each other, boots, shovels, or buckets— shake or rub gently, and leave the rest to dry out during curing.
If short on curing space, tops can be cut in the field, with a sickle bar mower or by hand, leaving stems as short as 1.5” or as high as 6”. In many cases, topping vs. not is dictated by curing scenarios—leaving tops on can facilitate hanging bulbs to cure, whereas topping plants is more conducive to curing in bulb crates or mesh bags. Recent Cornell trials have indicated that disease incidence does not increase when trimming garlic down at this stage.
Curing is important for successful bulb storage and finding the ideal conditions for curing can be a challenge. Curing in the field runs the risk of sunscald, while curing in poorly ventilated barns can result in yield loss from disease. Good airflow around the bulbs is critical. Avoid high temperatures (above 90°F) and bright sunlight. Stewart-Courtens notes that garlic will dry well even at 110°F but a physiological disorder called waxy breakdown starts to occur at about 120°F, so be sure to monitor temperatures in the drying area. Rapid curing can be achieved by placing trimmed bulbs roots-up on 1” wire mesh in a hoophouse or high tunnel covered with shade cloth, and with the sides and ends open. A well-ventilated barn will also work, but be sure that bulbs are hung with adequate air circulation or on open racks up off the floor. Curing takes 10 to 14 days and is complete when the outer skins are dry and crispy, the neck is constricted, and the center of the cut stem is hard.
Storing Bulbs. After curing, garlic can be kept in good condition for 1 to 2 months at ambient temperatures of 68 to 86°F under low relative humidity (< 75%). However, under these warm conditions, bulbs will eventually become soft, spongy and shriveled due to water loss. For long-term storage, garlic is best maintained at temperatures of 30 to 32°F with low relative humidity (60 to 70%). Good airflow throughout storage containers is necessary to prevent any moisture accumulation. Under these conditions, well-cured garlic can be stored for 6 to 7 months. Storage at higher temperatures (60°F) may be adequate for the short term, but it is important to select a place with low relative humidity and good air flow. As with onions, relative humidity needs to be lower than for most vegetables because high humidity causes root and mold growth; on the other hand, if it is too dry, the bulbs will dry out.
Storing Seed. Garlic bulbs that are to be used as seed for fall planting of next years’ crop should be stored at 50°F and at relative humidity of 65 to 70%. Garlic cloves break dormancy most rapidly between 40 to 50°F, hence prolonged storage at this temperature range should be avoided. Storage of planting stock at temperatures below 40°F results in rough bulbs, side-shoot sprouting (witch’s brooms) and early maturity, while storage above 65°F results in delayed sprouting and late maturity.
| Storage scenario | Length of Storage | Temperature | Relative Humidity |
|---|---|---|---|
| Short-term | 1-2 months | 68-86°F | <75% |
| Long-term | 6-7 months | 30-32°F | 60-70% |
| For seed | 50°F | 65-70% |
Garlic cloves used for seed should be of the highest quality, with no disease infections, as these can be spread to new fields and to the next year’s crop. See our Culling Garlic: Don’t Store or Plant Infected Bulbs article for what diseases and pests to look out for when preparing seed garlic. One of the most important clove-borne pests of garlic is garlic bloat nematode—keep an eye out for symptoms of this devastating pest and submit samples to the UMass Plant Disease Diagnostic Lab to make a positive identification; for submission instructions and contact info visit https://ag.umass.edu/services/plant-diagnostics-laboratory.
Over 2019 and 2020, Christy Hoepting of Cornell Cooperative Extension, conducted trials to evaluate various garlic curing and storage conditions. A planting of German hardneck garlic was divided up between 13 and 24 storage regimes in 2019 and 2020, respectively, and bulb characteristics including % shrink, bulb density, bulb firmness, wrapper tightness, bulb color, and Fusarium and black mold incidence were evaluated. Here are some take-home messages from the trials:
- The best-performing treatment was curing in a greenhouse with open sides, no fans, with garlic in mesh bags in a single layer on wooden pallets. After curing, the garlic was stored in a steel barn, where temperatures never dropped below 50°F and relative humidity ranged from 50-80%.
- Warm and humid storage conditions resulted in high incidence of Fusarium bulb rot, as would be expected.
- Cold storage reduced the incidence of Eriophyid mites, as lower temperatures inhibit their reproduction. E. mite populations will grow at room temperature.
- No consistent trends were observed in regards to topping vs. not topping. Neither practice led to higher rates of disease incidence or consistent differences in bulb quality. However, it does take longer to cure garlic with tops on (see Table 1).
- Washing or rainfall during curing reduced bulb quality and increased disease.
- Curing garlic in 1-ton boxes with heated forced air reduced bulb quality.
| Curing Condition | No. of Days to Complete Curing | ||
|---|---|---|---|
| Topping Conditions of Garlic During Curing | |||
| Temperature | Relative Humidity | Topped to 2-3" necks | Topped to 6-7" necks |
| 80°F | 90% | 19 days | 33 days |
| 80°F | 70% | 11 days | 19 days |
| 105°F | 90% | 7 days | 9 days |
| 105°F | 70% | 6 days | 7 days |
A useful summary from Hoepting’s write-up:
No matter the post-harvest practices used by our growers, the garlic came back fairly high quality. If you are happy with the quality of your garlic, do not change a thing. If your garlic has softer bulbs and looser wrapper leaves than you would like, consider adjusting your curing or storage conditions. Perhaps, it is being kept in the curing phase for too long and is being overdried. Maybe, you can cure it slower with natural ventilation instead of with fans, or top the bulbs to leave a longer neck (e.g. 6”). If you have issues with eryophyid mites showing up after storage, consider storing your garlic under cooler conditions. In very general terms, high humidity (>85%) for prolonged periods of time, no matter the temperature, can exacerbate diseases.
--UMass Extension Vegetable Program. Cornell Cooperative Extension garlic storage trials originally reported in Cornell Veg Edge Volume 18 Issue 14, on July 13, 2022.
News
USDA Emergency Commodity Assistance Program (ECAP)
ECAP is a one-time payment program administered by the USDA’s Farm Service Agency (FSA). It targets producers of eligible commodities who faced significant financial challenges in 2024 due to market uncertainties and increased production costs. The program offers per-acre payments based on planted and prevented planted acres, ensuring farmers receive support proportional to their operational scale. Payments cover 100% of planted acres—used for harvest, grazing, haying, silage, or similar purposes—and 50% of acres prevented from planting due to circumstances beyond producers’ control.
To be eligible, producers must meet the following requirements:
- Be actively engaged in farming.
- Have an interest in input expenses for a covered commodity.
- Have reported acreage of eligible commodities to FSA for the 2024 crop year planted and prevent plant acres to FSA on and FSA-578, Report of Acreage form.
- Have reported acres that were prevented from being planted to FSA for the 2024 crop year on an CCC-576 Notice of Loss form (if applicable).
Click here for more information on eligibility, payment rates, and how to apply.
Application deadline: August 15, 2025
Events
Twilight Meeting at Appleton Farms - Pest and Disease Management
When: Wednesday, July 16, 2025 from 4:00 pm to 6:00 pm
Where: Appleton Farms, 219 County Road, Ipswich, MA 01938
Registration: Event is free, no registration required.
Join us at Appleton Farms to learn more about pest management. Sue Scheufele of UMass Extension will talk about some of the most prolific and problematic pests and diseases in organic farming systems, including tips on scouting and pest identification. Learn to see the farm with fresh eyes!
Twilight meeting hosted by EMass CRAFT.
Questions? Contact Sue Scheufele, sscheufele[at]umass[dot]edu (sscheufele[at]umass[dot]edu)
Ecological Pest Management for Urban Farms
When: Saturday, July 19, 2025 from 10 am to 12 pm
Where: The Urban Farm, 78 Miller Street, Chelsea, MA 02150
Join UMass Urban Agriculture Extension, Joshua Arnold, Extension Professor in Urban Agriculture at UMass Amherst, and GreenRoots for a workshop on Ecological Pest Management for Urban Farms as part of the Urban Mentor Farm Program. Participants will learn practical, on-farm strategies to reduce pest pressure and minimize crop damage, along with effective preventative interventions to help avoid pest infestations and support resilient, healthy crops.
Refreshments and Spanish interpretation will be provided.
For more information and details in Spanish, click HERE or email us at urbanag[at]umass[dot]edu (urbanag[at]umass[dot]edu) or vladimirp[at]greenrootsej[dot]org (vladimirp[at]greenrootsej[dot]org)
** UMass Extension is grateful for support of this initiative by the National Institute of Food and Agriculture, U.S. Department of Agriculture, through the Northeast Sustainable Agriculture Research and Education (Northeast SARE) program under subaward number SNE23-004-MA-AWD00001024.
Sprayer Calibration Twilight Meeting at Blackbirch Vineyard
When: Tuesday, July 22, 2025 from 2:00 pm to 5:00 pm
Where: Blackbirch Vineyard, 108 Straits Rd, Hatfield, MA 01066
Registration: Event is free, please register in advance. Register here.
Come see George Hamilton, of Hillside Meadows Ag Consulting and previously with University of New Hampshire Extension, as he calibrates a Rears airblast sprayer, teaching us along the way. This workshop will help you think about the best way to achieve good coverage of your pesticide products on your crop, and then to double check that the coverage you think you are getting is being achieved. It will be most relevant to those of you using airblast sprayers in perennial crops, but we will be talking about sprayer calibration theory, which is useful no matter how you apply pesticides. We welcome both organic and conventional producers alike; even organic products will work more effectively if applied at the correct rate.
**3 pesticide credits will be available for this event.**
Questions? Contact Maria Gannett, mgannett[at]umass[dot]edu (mgannett[at]umass[dot]edu)
Twilight Meeting at Four Town Farm - Irrigation and Pest Management in Sweet Corn
When: Thursday, July 31, 2025 from 4:00 pm to 6:00 pm
Where: Four Town Farm, 90 George St., Seekonk, MA 02771
Registration: Event is free, please register in advance. Register here.
Chris Clegg grows 45 acres of sweet corn for sale at his farmstand and wholesale accounts. UMass Extension staff will discuss pest management in sweet corn focusing on weeds and insects, and Chris will explain how they have learned to control their biggest pest—BIRDS! Chris and his crew use netting on all 45 acres of sweet corn to keep out birds as well as corn earworm, come see how it works. We will also hear about the multiple water sources and irrigation tools Chris utilizes to keep crops watered across the many disparate fields that make up the farm, and how to manage food safety risk associated with different water sources.
This twilight meeting is hosted by SEMAP.
Questions? Contact Sue Scheufele, sscheufele[at]umass[dot]edu (sscheufele[at]umass[dot]edu)
Twilight Meeting at Reed Farm – Compost Production and Use
When: Wednesday, August 13, 2025, from 4 to 6 pm, followed by refreshments
Where: Reed Farm, 136 Russell Street, Sunderland, MA 01375
Registration: Event is free, please register in advance. Register here.
This program is for farmers who use compost, make compost or want to make compost! Reed Farm is a pasture-raised poultry farm that produces compost using materials generated on the farm. We’ll cover considerations for successful composting, using compost as a soil amendment, weed management and composting, and the MDAR Agricultural Composting Program and Composting Improvement Grant.
Questions? Contact Lisa McKeag, lmckeag[at]umass[dot]edu (lmckeag[at]umass[dot]edu) or 413-658-8631
Twilight Meeting at Ogonowski Farm - Sprayer Calibration
When: Tuesday, August 19, 2025 from 2:00 pm to 5:00 pm
Where: Ogonowski Farm, 713 Broadway Rd, Dracut, MA 01826
Registration: Event is free, please register in advance. Register here.
Come see George Hamilton, of Hillside Meadows Ag Consulting and previously with University of New Hampshire Extension, as he calibrates a crop care boom sprayer, teaching us along the way. This workshop will help you think about the best way to achieve good coverage of your pesticide products on your crop, and then to double check that the coverage you think you are getting is being achieved. It will be most relevant to those of you using boom sprayers in vegetable crops, but we will be talking about sprayer calibration theory, which is useful no matter how you apply pesticides. We welcome both organic and conventional producers alike; even organic products will work more effectively if applied at the correct rate.
**3 pesticide credits will be available for this event.**
Questions? Contact Maria Gannett, mgannett[at]umass[dot]edu (mgannett[at]umass[dot]edu)
40th Massachusetts Tomato Contest
When: Tuesday, August 19, 2025 from 8:45 am to 1 pm
Where: Boston Public Market, 100 Hanover St, Boston, MA 02108
Please join MDAR and the New England Vegetable and Berry Growers Association for the 40th anniversary of the Massachusetts Tomato Contest! This year’s contest will be held at the Boston Public Market on Tuesday, August 19th. 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 19th, or drop their entries off with a registration form at one of the regional drop-off locations on Monday, August 18th. Drop off locations include sites in South Deerfield, Southboro, North Easton and West Newbury. These tomatoes will be brought to Boston on Tuesday.
Details, including drop off locations, contest criteria, and registration form here. *Be sure to include the registration form with all entries.
The 40th 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? Please contact David Webber, David[dot]Webber[at]mass[dot]gov.
Save the Dates! Upcoming Cut Flower Events. More info coming soon.
September 18, Full Well Farm, Adams MA
November 6, Webinar, Connecticut and Maine Cut Flower Collectives
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.
