Event – American Cranberry Growers Association (ACGA) Summer Meeting

Date – August 17, 2017

Location– Rutgers P.E. Marucci Center, Chatsworth NJ

Agenda

CRANBERRY BOGS:

8:30–8:45 Opening Remarks
Shawn Cutts, President, American Cranberry Growers Association

8:45-9:05 Screening of POST Herbicides for Controlling Carolina Redroot (Lachnanthes caroliana) in New Jersey Cranberry Beds (Bog 6)
Thierry Besancon and Baylee L. Carr, P.E. Marucci Center for Blueberry & Cranberry Research & Extension, Rutgers University, Chatsworth, NJ

9:05–9:25 Breeding for Fruit Rot Resistance: Evaluation of the Next Cycle of Crosses (Bog 8)
Nicholi Vorsa, P.E. Marucci Center for Blueberry & Cranberry Research & Extension, Rutgers University, Chatsworth, NJ

9:25–9:45 Performance of Welker and Haines and other Advanced Selections (Bog 10)
Jennifer Johnson-Cicalese and Nicholi Vorsa, P.E. Marucci Center for Blueberry & Cranberry Research & Extension, Rutgers University, Chatsworth, NJ

9:45-10:10 Research on Diseases of Cranberries (Bog 15)
Peter Oudemans, Department of Plant Biology and Pathology, Rutgers University

10:10-10:30 Is Mycorrhizal Inoculation Efficacious? (Bog 18)
James Polashock, Research Plant Pathologist, USDA-ARS

10:30–10:50 On-going Research on Sucking Insect Pests (Bog 19)
Cesar Rodriguez-Saona, Department of Entomology, Rutgers University; Vera Kyryczenko-Roth, P.E. Marucci Center; and Robert Holdcraft, P.E. Marucci Center, Chatsworth, NJ

10:50–11:10 Show and Tell
Cranberry growers

CONFERENCE ROOM:

11:20–11:30 Cranberry Statistics
Bruce A Eklund, State Statistician, U.S. Department of Agriculture | National Agricultural Statistics Service

11:30–12:00 Root Growth in Cranberries
Amaya Atucha, Assistant Professor, and Beth Workmaster, Department of Horticulture, University of Wisconsin-Madison

12:00–1:00 LUNCH (Pole Barn)

1:00–1:30 Farm Safety
Ray Samulis, Cooperative Extension Agent, Burlington County Extension, Rutgers University

We are seeing an increase in the number of nymphs of toad bugs in cranberry beds. Growers need to be aware of this insect and treat if numbers reach high levels (there is no current threshold). We are currently conducting studies to estimate the density of toad bugs that can cause economic injury to cranberries.

Life cycle. Toad bugs, Phylloscelis atra, feed only on cranberries. This insect has a single generation per year. It overwinters as eggs. The nymphs appear by the end of June through early September, and the adults from end of July through October (harvest). Eggs are laid from end of August through October.

Damage. Feeding damage can be noticed in two stages. First stage feeding damage on vines causes closing in (towards the branch) of the leaves on the new growth. Second stage feeding causes changed in color (reddish to brown) of new growth. The damage can be seen from July until harvest. This damage will cause dying of the branch and the berries to shrivel up. Heavy infestation will result in dwarfed berries.

Management. To determine infestation, lightly sweep problematic beds (bugs should be easy to catch in sweep nets as they are very active). Because this is a new pest there is no threshold established yet. Thus, insecticide applications should be based on the relative number of bugs per sweep compared with other sites and previous history of infestation. Currently, growers can use the following control options: Sevin 4F (broad-spectrum carbamate), Diazinon, Imidan 70W (broad-spectrum organophosphates), Actara or Assail 30SG (neonicotinoid insecticides, effective against piercing-sucking insects). If infestation is high, treatments should be applied at this time of the year.

For more information, please see “The Cranberry Toad-Bug” by F.A. Sirrine and B.B. Fulton. 1914. New York Agricultural Experiment Station. Bulletin No. 377. Department of Agriculture, Geneva, NY.

Based on our degree-day (DD) model for Sparganothis fruitworm, first eggs hatched at about 900 DD (see chart). As of July 05, Sparganothis has accumulated 1,358 DD (using March 1 as biofix) or 1,318 DD (using April 1 as biofix). This indicates that most eggs should have hatched by now and fruit is susceptible to infestation. Most beds are out of bloom (early varieties) or should be coming out of bloom. Thus, if trap counts have been high, then a post-bloom application might be necessary. Growers should consider treatment in the next few days (as soon as bees are removed) to prevent damage to berries. Your best post-bloom options are Diazinon, Altacor, or Delegate.

Based on our degree-day (DD) model for Sparganothis fruitworm, peak flight is expected at around 884 DD and first eggs hatched expected at 895 DD (see chart). As of June 25, Sparganothis has accumulated 1,118 DD (using March 1 as biofix) or 1,078 DD (using April 1 as biofix). This indicates that we have passed peak flight and eggs have started to hatch. I will keep you updated as the season progresses.

Cranberry beds are in bloom. If insects have been effectively managed prior to bloom, we recommend no sprays at this time. A reminder: when bees are present your only 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 activity of Sparganothis fruitworm and blackheaded fireworm, two key pests in New Jersey.

Sparganothis fruitworm- Damage by the second generation larvae begins after the eggs hatch, usually 9-12 days after they are laid. Based on our DD model, eggs have started to hatch (see above). These larvae will feed on foliage and fruit. Larvae will partially feed on berries, causes scarring of the fruit. However, particularly on Ben Lear, larvae may feed inside the fruit. Insecticide treatment should target small larvae. Pheromone traps can be utilized to time insecticides sprays. If treatment is required, sprays should be applied two weeks after peak moth flight and/or earlier if using an IGR. If trap counts indicate a low population that requires management, a single insecticide application may be made post-bloom. If trap counts are high, then an early application of an IGR may be used when the first eggs start to hatch, i.e., at this time of the year (this is most critical for early varieties). This would be followed by a second application soon after bloom, which is approximately 1,400 DD and will most likely coincide with the 1st-2nd week in July. Your post-bloom options are Diazinon, Altacor, Delegate, or Intrepid.

As indicated above, controlling fruitworm populations is often very difficult and many require multiple applications depending on pest pressure. Sparganothis fruitworm populations in Massachusetts are resistant to organophosphate insecticides (e.g. Diazinon, Lorsban). Thus, organophosphates should be used with care, i.e., always rotate insecticides with different modes of action. Organophosphate insecticides will also negatively affect natural enemy populations. Delegate, Intrepid and Altacor are reduced-risk insecticides registered against fruitworms and can be used as an alternative to organophosphates post-bloom.

Based on our degree-day model for Sparganothis fruitworm, first eggs laid are expected at around 681 DD (see chart). As of June 13, Sparganothis has accumulated 814 DD (using March 1 as biofix) or 774 DD (using April 1 as biofix). This indicates that egg laying has just started but eggs are not expected to hatch yet. Reminder that a single insecticide application, i.e., post-bloom application with Delegate, Altacor, Diazinon, or Intrepid, aimed at Sparganothis larvae will likely have the greatest effect if it is timed for peak egg-hatch/larval-emergence, which is approximately 1,400 DD and will most likely coincide with the 1st-2nd week in July. I will keep you updated as the season progresses.