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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Insect Pest Management During Bloom – June 12, 2024

Cranberries have started to bloom, and bees are active in bogs. If insects have been effectively managed prior to bloom, we recommend no sprays at this time. A reminder: when bees are present, your choices of insecticides are insect growth regulators (IGRs) such as Intrepid 2F or Bt products such as DiPel.

During bloom, we recommend monitoring insect populations using pheromone traps. Pheromone traps should be used particularly to monitor the activity of Sparganothis fruitworm and blackheaded fireworm, two key pests in New Jersey.

Degree-Day Model for Sparganothis Fruitworm

Sparganothis fruitworm adults

Together with Dr. James Shope, Assistant Extension Specialist in the Department of Environmental Sciences at Rutgers University, we have been working on refining a degree-day model for Sparganothis fruitworm using trapping data from New Jersey. According to this model, 25% flight activity should occur at 840 degree-days, and peak flight activity at 952 degree-days (starting on April 15). As of today, Sparganothis fruitworm has accumulated 724 degree-days, indicating that flight should have started but has not yet reached 25%. Note that this model includes data from many bogs and varieties, which may behave differently from the overall model. Therefore, it is advised to monitor closely as the expected peak flight approaches.

Blunt-nosed Leafhoppers in Cranberries – 2024

New Jersey cranberry growers are increasingly concerned about rising blunt-nosed leafhopper (BNLH) populations. This rise is attributed to changes in pest management strategies, such as the adoption of new reduced-risk products and decreased use of broad-spectrum insecticides, as well as the expansion of high-yielding varieties that seem more susceptible. BNLH is particularly worrisome because it transmits a phytoplasma, a type of bacteria, that causes false blossom disease. Symptoms of false blossom disease include stunted growth, erect sterile flowers (Figure 1), and distinctive branching of upright shoots, known as witches’ broom.

False blossom infected cranberry with erect flowers (left) and uninfected cranberry (right). Photo credit: Beth Ferguson.

Life Cycle

BNLH has one generation per year. Its eggs overwinter and begin hatching in early May. Nymphs go through five instars in about a month. Adults appear in early July, peak in mid-late July, and their numbers diminish by the first week of August. These adults have a distinctive blunt head and range in color from light yellowish-gray to dark brown. Eggs are laid between July and August.

Damage

Nymphs and adults feed on cranberry plant juices using their piercing-sucking mouthparts. This direct injury is not noticeable. However, they are significant as vectors of the phytoplasma that causes false blossom disease.

Management

At this time of the year, we are observing early-instar nymphs, mostly 2nd instars but also 3rd instars (Figure 2).

Blunt-nosed leafhopper nymphs. Photo credit: Beth Ferguson

Here are some guidelines to consider when managing BNLH in cranberries:

  1. Identify Infestation Sites: The key to BNLH control is locating infestation sites. The best way to monitor for this insect is with an insect sweep net. Before bloom, use sweep nets to monitor nymphs. Since nymphs are small, freeze the samples to kill them, then count the nymphs under a microscope or with a magnifying lens.
  2. Sweep-net Monitoring: Perform sweep sets of 25 sweeps each. The recommended number of sweep sets is:
  • 1 per 1–10 acres
  • At least 10 sweep sets per 10–20 acres
  • 1 sweep set per 2 acres for areas larger than 20 acres
  1. Lack of Economic Thresholds: Managing BNLH is challenging because they vector a phytoplasma causing false blossom disease. Establishing economic thresholds is difficult due to the unknown proportion of infected individuals in the population, which can vary by variety. Higher infection rates have been observed in newer varieties even when BNLH populations are low.
  2. Control Measures: Consider control measures based on BNLH numbers relative to previous years, history of insecticide application, and cranberry variety. If BNLH populations are increasing compared to previous years and the beds have not been treated for BNLH in 2-3 years, growers should consider treatment.
  3. Treatment Options: If treatment is necessary, consider the following options to manage BNLH:
  • Timing: The best time for insecticide treatment is before bloom to target young nymphs.
  • Insecticides: Organophosphates: Diazinon (diazinon), Orthene (acephate); Carbamates: Sevin (carbaryl); Pyrethroids: Fanfare or Brigade (bifenthrin), Danitol (fenpropathrin); Neonicotinoids: Assail (acetamiprid), Actara (thiamethoxam). Note: Do not use before bloom due to potential negative effects on bees, as these systemic insecticides can accumulate in pollen and nectar. Sulfoxaflor: Closer (sulfoxaflor). Although effective in small plot trials at the P.E. Marucci Center, more data are needed to confirm efficacy on larger commercial scales.
  • Be aware that, while not scientifically proven, there are claims that Orthene and Sevin may reduce pollinator activity by repelling bees.

Grape and Wine Science Certificate Program

Grape and Wine Science Certificate Program will be offered July 22-Aug 16, 2024. This program will provide foundational knowledge in three major areas of grape and wine science – grape growing, wine making, and business operations – following the path of grapes from the field to the winery to the glass. Students will gain competency in all three areas to prepare them for positions in the industry. The program will feature 4 weeks of classroom instruction, complemented by hands-on workshops. Then students will complete a 4-week winery internship where they can put their new knowledge and skills into practice. [Read more…]

South Jersey Tree Fruit Twilight Meeting – II

When: May 21 (Tuesday) @ 5 pm

Where: Nichols Orchards: 628 Royal Ave., Franklinville, NJ 08322

Pesticide credits: 1A (5), PP2 (5), and 10 (5) [Read more…]

NJ Depts of Agriculture & Environmental Protection Allow Controlled Open Burning to Protect Crops

(Trenton) [On April 20, w]ith 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 today, April 20, through Saturday, April 27.

Temperatures are expected to drop to the 30s or below tonight 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 Department of Agriculture are allowing these steps to protect farmers’ livelihoods and to ensure that consumers will be able to 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 to protect 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 the implementation of either technique but 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.

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To learn more about the New Jersey Department of Agriculture, find us on Facebook at www.facebook.com/NJDeptofAgriculture and www.facebook.com/JerseyFreshOfficial or Twitter @NJDA1 and @JerseyFreshNJDA.

Statewide Wine Grape Twilight Meeting.

Sponsored by the New Jersey Center for Research and Education, the program’s highlight is the demonstration of the new in-row weeding machine from TILMOR by Allonardo Enterprises. There will also be a demonstration talk on Groundhog management and other wildlife management in the vineyard. The program details are below. The sequence of presentations may change depending on the set-up at the winery. [Read more…]