Fruit Crops Edition - Cranberry Section

Seasonal updates on diseases, insects, weeds impacting small fruit (blueberry, cranberry, and wine grape). Fruit Pest Alerts are also available via this category feed.
 
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May 22, 2026

Blunt-nosed Leafhopper in Cranberries (22 May 2026)

By: Yahel Ben-Zvi and Cesar Rodriguez-Saona

Rutgers P.E. Marucci Center

New Jersey cranberry growers are increasingly concerned about rising populations of the blunt-nosed leafhopper (BNLH). This increase is likely associated with shifts in pest management strategies, including the adoption of reduced-risk insecticides and decreased use of broad-spectrum products, as well as the expansion of high-yielding cranberry varieties. BNLH is particularly problematic because it transmits a phytoplasma—a type of bacterium that causes false blossom disease (Figure 1). Symptoms of this disease include stunted growth, deformed and sterile flowers that point upward, and a characteristic branching of upright shoots known as witches’ broom.

Figure 1. Cranberry false blossom disease symptoms in mid-May. Note the clustered branching of ‘witches’ broom’, erect and sterile flower buds, and more redness in the leaves. Photo by Yahel Ben-Zvi.

Life Cycle

BNLH has one generation per year (Figure 2). Its eggs overwinter embedded in cranberry stems and begin hatching in early May. Nymphs pass through five instars over approximately two months. Adults emerge in early July, peak in mid- to late July, and decline by the first week of August (Figure 3). Adults are characterized by their distinctive blunt heads and vary in color from light yellowish-gray to dark brown. Egg laying occurs between July and August.

Damage

Nymphs and adults feed on cranberry plant sap using their piercing-sucking mouthparts. Although direct feeding causes little visible damage, BNLH is an important pest because it serves as a vector of the phytoplasma that causes false blossom disease.

Management

At this time of year, early-instar nymphs should be active (Figure 2). Here are some guidelines to consider when managing BNLH in cranberries:

  1. Identify Infestation Sites: The key to effective BNLH control is identifying infestation sites. The most reliable method for monitoring this insect is the use of a sweep net. Before bloom, use sweep nets to collect nymphs. Because nymphs are small and difficult to see, bag and freeze the samples to kill them, then count the nymphs using a microscope or magnifying lens.
  2. Sweep Net Monitoring: Perform sweep sets consisting of 25 sweeps each. The recommended number of sweep sets is:
    • 1 per acre

      Figure 2. An early-instar blunt-nosed leafhopper nymph in mid-May. Photo by Yahel Ben-Zvi.

    • At least 10 sweep sets for 10–20 acres
    • 1 sweep set per 2 acres for areas larger than 20 acres
  3. Lack of Economic Thresholds: Establishing an economic threshold for BNLH is difficult because the proportion of phytoplasma-infected individuals within BNLH populations is unknown and may vary by cranberry variety and location. Notably, higher infection rates have been observed in newer varieties, even when BNLH populations are low.
  4. Control Measures: Management decisions should be based on BNLH population trends relative to previous years, the history of insecticide applications, and the cranberry variety grown. If BNLH populations are increasing compared to prior seasons and beds have not been treated for BNLH during the past 2–3 years, treatment should be considered.
  5. Treatment Options: If treatment is necessary, consider the following options for managing BNLH:
    • Timing: The best time for insecticide applications is before bloom to target young nymphs.
    • Insecticide Options:
      • Organophosphates: Diazinon (diazinon), Orthene (acephate)
      • Carbamates: Sevin (carbaryl)
      • Pyrethroids: Fanfare or Brigade (bifenthrin), Danitol (fenpropathrin)

        Figure 3. Life cycle of the blunt-nosed leafhopper. Drawing by Lindsay Lindhult.

      • Neonicotinoids: Assail (acetamiprid), Actara (thiamethoxam)
        Note: Use neonicotinoids with caution before bloom because of their potential negative effects on pollinators. These systemic insecticides can accumulate in pollen and nectar, posing risks to bees.
      • Sulfoximines: Transform (sulfoxaflor). Although effective in small-plot trials at the P.E. Marucci Center, additional data are needed to confirm efficacy at larger commercial scales.
    • Although not scientifically proven, there are claims that Orthene and Sevin may reduce pollinator activity by repelling bees.
    • Rotate insecticides with different modes of action to help prevent the development of resistance in pest populations.
Filed Under: Cranberry, Fruit
May 17, 2026 and

April 2026 Frost Damage in Fruit Crops Survey

We invite you to participate in a brief survey to better understand how April frost events have affected crop production, economic impact, and how growers are managing this risk. The information collected will help us assess the overall severity of the frost and compile broad, aggregated data to effectively communicate its impact to legislative offices and Farm Service Agency, and others.  Your input will help also inform research and Extension programs to support fruit growers in New Jersey better.

Please note that your responses are strictly confidential and will only be reported in aggregate. You should be 18 years or older and involved in fruit production to respond to this survey. Approximate time – 10-12 min.

Ready to start? Please click the link below:

https://rutgers.ca1.qualtrics.com/jfe/form/SV_6zliIMszIABIRjU

If you have any questions or concerns, please contact Seowoo Sophie Lee (seowoo.lee@rutgers.edu) or Hemant Gohil gohil@njaes.rutgers.edu

Thank you for your valuable time.

Sincerely,

This document was approved by the Rutgers University Institutional Review Board for the Protection of Human Subjects on May 13, 2026.

Filed Under: Blueberry, Cranberry, Fruit, Strawberry, Tree Fruit, Wine Grape Tagged With: , , , , , , , , ,
April 27, 2026

South Jersey Wine Grape Twilight

When:     May 20 (Wed) 5:00 PM
Where:    Saddlehill Winery and Vineyards: 1407 White Horse Rd, Voorhees Township, NJ 08043
Credits:  CORE; PP2; 1A; 10

5:00 pm Welcome and Updates
        Bill Green, Owner, Saddlehill Winery
        Hemant Gohil, Gloucester County Extension Agent, Rutgers NJAES

        Drone in Vineyard Applications – Demonstration
        What Should You Know to Legally Fly Drones in Agricultural Applications?
        Nathan Graham, UAV/Drone Specialist, Hoober Inc., PA.

        Field Observations from the Wine Grape IPM Pilot Program
        Janine Spies, Statewide Fruit IPM Program Leader, Rutgers NJAES.

        Insect Pest Management in the Vineyard
        Anne Nielsen, Extension Specialist in Fruit Entomology, Rutgers NJAES.

        Timing, Chemistry, Coverage: The Formula for Effective Disease Control
        Nancy Sharma, Extension Specialist, Fruit Pathology, Rutgers NJAES.

        Weed Management Updates for Vineyard
        Thierry Besancon, Extension Specialist, Weed Science, Rutgers NJAES.

        Pesticide recertification credits and adjourn.

Light fare will be provided. 
If you plan to attend, please email Joan Medany at jmedany@co.gloucester.nj.us or call 856-224-8030. 
For additional assistance, please contact Hemant Gohil at 856-224-8029 before the meeting.

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Filed Under: Blueberry, Cranberry, Fruit, Strawberry, Tree Fruit, Wine Grape Tagged With: , , ,
April 20, 2026

NJ DEP issues Controlled Open Burn Permit from April 18, through Wednesday April 22.

(TRENTON) – With the state expected to experience cooler spring temperatures, the Department of Environmental Protection has agreed with NJDA Secretary Ed Wengryn’s request to allow farmers to do controlled open burning or use specialized torches known as smudge pots to protect flowering crops from damage beginning Saturday, April 18, through Wednesday, April 22. Temperatures are expected to drop to the 30s or below this week with varying winds through portions of the state. These expected temperatures follow warm temperatures in recent days. Damage from freezing weather now can significantly reduce yields of certain fruits and vegetables that are in the flowering stage.

The DEP and the Department of Agriculture are allowing these steps to protect farmers’ livelihoods and ensure that consumers can enjoy an ample supply of Jersey produce later this year.  The DEP intends to exercise its authority and discretion under the Air Pollution Control Code, N.J.A.C. 7:27, et seq., and other applicable authorities to permit the following procedure for open burning or the use of smudge pots to assist farmers in protecting their crops in low temperatures. Farmers who believe they will need to conduct open burns and/or use smudge pots must provide notice to the DEP’s 24-hour Communications Center at 1-877- WARNDEP (1-877-927-6337). Notification to DEP does not require implementing either technique, but it ensures proper procedures are followed should they become necessary. If a farmer does not call DEP in advance but uses either technique, the farmer must notify DEP by 9 a.m. the following day. The farmer will be asked which technique was used. Farmers must record the incident number provided to them by the Communications Center. The following information is to be provided:

 Name of the individual making the decision to conduct the open burning/use of smudge pots and name of the farm.

  • Actual street address of the farm on which either technique will be used (no P.O. Boxes).
  • Telephone number of a contact at the farm.
  • Predicted temperature (in degrees Fahrenheit) at the agricultural operation when the technique will be used.
  • Wind speed anticipated when the technique will be used.
  • Predicted hours of open burning and/or use of smudge pots.
  • Materials expected to be burned.
  • At the time of the initial call to the Communications Center, farmers will be given an email address and incident number.

Within two days, they must submit to DEP via this email address the following information:

  • The DEP Communications Center incident number.
  • Ambient temperature (in degrees Fahrenheit) at the time the technique was used.
  • Actual wind speed at the orchard at the time the technique was used.
  • A statement verifying that all restrictions in the open burning or use of smudge pots were followed.
  • The New Jersey Department of Environmental Protection and New Jersey Forest Fire Service caution all farmers and agriculture businesses with respect to the use of open burning in high wind velocity conditions. Please take note that farmers are encouraged to utilize smudge pots for warming as necessary during higher wind conditions. Use of open burning when wind velocity is greater than 5 mph is strictly prohibited, may contribute to wildfire risk, and can carry significant penalties.
  • Smudge pots must be fueled only with either kerosene or No. 2 fuel oil.
  • Open burning can consist only of either the following materials: clean and untreated scrap lumber, felled trees, clippings pruned from trees and shrubs, hedgerows, or firewood. Absolutely no refuse, trade waste, tires or garbage of any type may be added to the authorized open burning material.

 The New Jersey Department of Environmental Protection and New Jersey Forest Fire Service caution all farmers and agriculture businesses with respect to the use of open burning in high wind velocity conditions. Please take note that farmers are encouraged to utilize smudge pots for warming as necessary during higher wind conditions. Use of open burning when wind velocity is greater than 5 mph is strictly prohibited, may contribute to wildfire risk, and can carry significant penalties.

###

The New Jersey Department of Agriculture (NJDA), established in 1916, serves New Jersey’s agricultural community and residents through a wide range of programs across its divisions that ensure the preservation and continuation of the state’s agricultural landscape.  NJDA works to ensure the safety and quality of New Jersey’s food supply, protect animal and plant health, and promote the overall long‑term viability of agriculture. The Department also connects consumers with New Jersey’s farmers and locally grown products while supporting the state’s diverse agricultural industry through initiatives of the Jersey Fresh program.  

For more information about the New Jersey Department of Agriculture, follow us on Facebook at www.facebook.com/NJDeptofAgriculture and www.facebook.com/JerseyFreshOfficial; on Instagram @njdeptofagriculture; on X/Twitter @NJDA and @JerseyFreshNJDA; and on LinkedIn at New Jersey Department of Agriculture. 

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Filed Under: Blueberry, Cranberry, Fruit, Strawberry, Tree Fruit, Vegetable Crops, Wine Grape Tagged With: , , ,
April 16, 2026

Farm Safety Needs Assessment Closing May 1

The Rutgers Farm Health and Safety Working Group is conducting a survey to evaluate the priority needs of New Jersey farmers for training and resource development related to safety and health.  As a New Jersey farmer, you are invited to complete this survey by Friday, May 1, 2026. Click here to access the survey and learn more.  [Read more…]

Filed Under: Agrivoltaics, Blueberry, Christmas Trees, Commercial Ag Updates, Cranberry, Disease Forecasting, Field, Forage & Livestock, Food Safety, Fruit, Landscape, Nursery, & Turf, Nursery, Organic Production, Strawberry, Tree Fruit, Turf, Vegetable Crops, Wine Grape Tagged With: ,
April 10, 2026

Assessing the Severity of Frost Damage to Peach and Apple Flower Buds

Figure 1. The brown and shrunken pistil (L) indicates the flower is dead; a green and upright pistil indicates that the flower is alive. Photo by H. Gohil.

The below-freezing temperatures on Wednesday (4/8/26) and Thursday (4/9/26) early mornings are likely to cause frost damage in several peach and a few apple orchards in New Jersey. It got down to 25°F–28°F in Southern NJ, and 22°F -27°F in Central and Northern NJ, and those temperatures could have killed vulnerable blossoms. The night of April 8th saw wind speeds above 10 mph, which mixed the cold air at the bottom with the warm air above. This prevented cold-air stratification and reduced the heat loss from the soil surface and plant tissues. The night of April 9th was even colder, and the wind dropped below 5 mph, almost coming to a standstill for a few hours. This causes the rapid loss of thermal energy from the soil and plant tissues. Most unprotected peach and a few apple orchards were affected by these conditions on the night of April 9th. In several parts of New Jersey, peach flower buds were at full bloom, the most susceptible stage to frost (Fig. 1). In Apples, though most orchards were in the tight cluster or earlier stages of bud development, and few varieties were in the first pink. The critical temperatures for 90% bud kill at these stages are 21°F for the tight cluster and 24°F for the first pink; hence, only a few apple orchards in South NJ were vulnerable to significant frost damage (Fig. 2).

Figure 2. Frost damage to Apple bloom at first pink

In Peach, not all flowers bloom at the same time, which makes frost-damage assessment a little more difficult. Often, many flowers look damaged, but they still bear fruit. This estimate can be even more difficult in some varieties, simply because they bloom so much that even 90% damage can yield close to the full crop. The natural tendency is to look for open flowers, which can easily lead to overestimating the damage. The developing flower buds will quickly die once damaged by a freeze. You can’t tell what will happen just by looking at the flower. The browning of flower petals doesn’t mean the ovary is dead.

You can do a quick, destructive assessment of loss by randomly opening 10-20 flowers per tree; do this on 5-10 trees across an acre or block for each variety. This can give a relative estimate of bloom loss. If you take a more systemic approach, you may get more accurate results. Due to cold-air stratification, cold air settles to the bottom, so more buds are damaged at the bottom; therefore, you want to sample from both the upper and lower branches. Sometimes, the loss of flower buds could be as good as natural thinning. So, flower bud loss may not result in a crop loss.

After opening the flower, if the pistil is shrunken and brown, consider it dead; and if completely green, consider it alive (Fig 1). The pistil is sticking out, and you see it is brown; it could have been pollinated and is in the senescence stage. It is not brown because of frost, but it’s brown because of the normal progression of development. In another scenario, the pistil is brown because it has frost damage, but it still may have done its job of pollination. It served its purpose and senescence because both frost and pollination are over. After pollination and fertilization, rapid hormonal changes enhance fruit development and make them slightly more cold-hardy. So even the destructive analysis is a close approximation.

Figure 3. Uneven development of peach due to frost injuries, represented by very small ripe fruits in PF Flamin Fury 24 (Left) and Silverglo (right), and a significant number of green unripe fruits in Lady Nancy (middle). Photo by H. Gohil.

If frost occurs at the shuck-split or shuck-off stage, the seed/pit will be damaged. But the fruit looks normal. However, they will not reach full size because the nonviable seed cannot produce the hormones required for fruit growth (Fig. 3). Even if they do grow, they may still face other problems. For example, the pit may have sustained damage, predisposing it to shatter during phase III of fruit growth. If you wait for a week to 10 days, it will be easier and more accurate non-destructive assessment. The live flowers will develop normally, and the dead flowers will be shrunken brown mummies that can be flicked away easily. You will still have plenty of time to adjust fruit thinning to achieve a near-normal crop. You should not be in a hurry to do fruit thinning this year! If you see some fruits that have stopped getting bigger and are distinctly smaller, will you want to thin? Maybe after the June drop.

Filed Under: Blueberry, Cranberry, Fruit, Strawberry, Tree Fruit, Wine Grape Tagged With: , , ,