Archives for May 2023

May 31, 2023

Vegetable IPM Update 5/30/23

Sweet Corn

Due to continued cold night temperatures, European corn borer (ECB) moth captures have been extremely low in northern and central county light traps.  Thus far this flight has been weak, and no feeding has been detected on whorl and pre-tassel stage sweet corn as far south as northern Burlington County.  An increase in nighttime temperatures (even temporarily) may result in somewhat higher numbers over the next week.   Whorl corn is the primary target for egg laying.  If the first flight is late rather than nonexistent, this sometimes results in heavier infestations on 2nd and 3rd plantings than on the first.  Feeding levels could be somewhat higher in the southern counties, and should rise over the next 3 weeks.

European corn borerLook for the characteristic “shot-hole” type of feeding (photo below at right) and consider treating when infested plants exceed 12% in a 50 plant sample.  As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left).  It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time.  This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.

 

 

Useful insecticides for this particular application include synthetic peasts on a leafpyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn.  Control with these materials is very inconsistent.

The highest nightly trap catches of ECB for the week ending 5/30/23 are as follows:

Blairstown   1 Princeton   1
Chester   1 Sergeantsville   1
Morristown   1 South Branch   1

[Read more…]

Filed Under: Organic Production, Vegetable Crops
May 30, 2023

Pasture Walk in Burlington County on Thursday, 6/1

Rutgers Cooperative Extension of Burlington County invites you to a Spring Pasture Walk to be held at the Burlington County Agricultural Center on Thursday, June 1, 2023. Meet us under the red market barn and we’ll begin our walk through the sheep pastures promptly at 6:30 p.m. [Read more…]

Filed Under: Field, Forage & Livestock Tagged With: , ,
May 27, 2023

Beware of Cryptomeria Scales on True Firs within Christmas Tree Farms

Armored scales are generally regarded by green industry plant managers as being one of the more difficult insect pests to control. The Cryptomeria scale (Aspidiotus cryptomeriae ‘Kuwana’) is an armored scale that is notorious for being especially difficult to detect because of the translucent waxy cover. The elongate hemlock scale species resembles this scale, but it has a waxy cover that is caramel brown in color. Although the hosts of Cryptomeria scale can potentially include numerous conifer species, they are most typically found on hemlocks & pines in the landscape and on true firs in production situations such as Christmas tree farms. The damage potential is especially high on true firs.

Cryptomeria Scales on balsam fir needles

Signs of Cryptomeria scales beneath needles. (Photo: Steven K. Rettke, Rutgers Coop. Ext.)

Cryptomeria scale symptoms on Fraser fir

Chlorotic banding & mottling symptoms produced by Cryptomeria scales on Fraser fir (Photo: Steven K. Rettke, Rutgers Coop. Ext.)

 

 

 

 

 

 

 

 

 

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Filed Under: Christmas Trees
May 27, 2023

Managing Blunt-nosed Leafhoppers in Cranberries – 2023

Blunt-nosed leafhoppers (BNLH) are important pests of cranberries in NJ because they vector a phytoplasma that causes false blossom disease. BNLH has one generation a year. It overwinters as eggs, which begin to hatch in early May. The nymphs will go through five instars in about a month. The adults begin to appear by the end of June and are most abundant in mid-July. Numbers of this species start to diminish by the end of July. The adults have a characteristic blunt head and vary from light yellowish-gray to dark brown. Eggs are laid in June-July. Nymphs and adults get their food by sucking the plant juices of the cranberry vines with their piercing-sucking mouthparts. At this time of the year, we are observing early-instar nymphs, mostly 1st instars but also 2nd instars (Figure 1).

Blunt-nosed leafhoppers

Figure 1. Blunt-nosed leafhoppers early-instar nymphs. Photo credit: Paolo Salazar-Mendoza.

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

  1. The most important point in BNLH control is locating the sites of infestation. Monitoring for this insect is accomplished best with an insect sweep net. Nymphs should be monitored before bloom using sweep nets (this time of year). Nymphs before bloom are small (Figure 1); thus, ideally, you may need to freeze the samples (to kill them), and then count the number of nymphs under a microscope or using a magnifying lens.
  2. To monitor, 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, and 1 sweep set per 2 acres for more than 20 acres.
  3. A challenge for managing BNLH is the fact that they vector a phytoplasma that causes false blossom disease. For this reason, it is difficult to establish economic thresholds for this pest because we do not know the proportion of individuals that are infected in the population. Moreover, this proportion can vary depending on the variety. For instance, we have observed higher incidence of infection in the newer varieties even when populations of leafhoppers are low.
  4. Control measures should be considered based on the number of BNLH relative to previous years, history of insecticide application, and the variety. If BNLH populations are increasing compared to previous years and the beds have not been treated for BNLH for 2-3 years, growers should consider treatment.
  5. If treatment is necessary, we have a few options to manage BNLH. The best timing for insecticide treatment is before bloom to target the young nymphs. We recommend the use of organophosphates such as Diazinon (diazinon) and Orthene (acephate), carbamates like Sevin (carbaryl), and pyrethroids like Fanfare (bifenthrin) and Danitol (fenpropathrin). Although not proven scientifically, there are claims that Orthene and Sevin can reduce pollinator activity by repelling bees. The neonicotinoids Assail (acetamiprid) and Actara (thiamethoxam) also work well against nymphs, but we do not recommend their use before bloom due to potential negative effects on bees; neonicotinoids are systemic insecticides that can accumulate in the pollen and nectar. Closer (sulfoxaflor) is a new registered insecticide in cranberries with a similar mode of action as the neonicotinoids but that belongs to a different class of insecticides. We have tested Closer in small plot trials at the P.E. Marucci Center and shown that it is effective against BNLH nymphs; however, more data are needed to confirm its efficacy at larger scales in commercial farms.
Filed Under: Cranberry, Fruit
May 24, 2023

Vegetable IPM Update 5/24/23

Sweet Corn

Scattered European corn borer (ECB) moths are now being captured in central and northern counties, and this insect is certainly active in southern parts of the state.  Numbers are quite low.  It remains to be seen whether this first flight will amount to much, but recent years’ catches give no reason to suspect that a large population will develop.   Whorl corn is the primary target for egg laying, but as yet, scouts have reported no signs of feeding injury.  In northern and central counties, corn plantings that were started on/under plastic are now reaching a size that will support ECB larvae.  We expect to encounter some level of feeding over the next 2 weeks, although the majority of plantings have not required insecticide treatments for ECB prior to full tassel in the past several years.

European corn borerLook for the characteristic “shot-hole” type of feeding (photo below at right) and consider treating when infested plants exceed 12% in a 50 plant sample.  As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left).  It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time.  This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.

Useful insecticides for this particular application include synthetic damaged leafpyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen.  Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn.  Control with these materials is very inconsistent.

The highest nightly trap catches* of ECB for the week ending 5/24/23 are as follows:

Asbury   1 Matawan   1
Chester   1 New Egypt   1
Denville   1 Old Bridge   1
Long Valley   1 Oldwick   1

*  No blacklight traps are in operation south of the Columbus (Burlington Co.) area this season.

[Read more…]

Filed Under: Organic Production, Vegetable Crops
May 24, 2023

Tree Fruit IPM Report for May 25, 2023

Peach:

Bacterial Spot: Generally we recommend starting at 0.5 ozs metallic copper and gradually lowering the rate as the season progresses. The rate applied will depend on the formulation. Dr. Lalancette published a chart listing common copper formulations and rates for peach and nectarine applications. Avoid combining copper with captan especially if it has been overcast for several days. Also avoid acidic spray solutions when applying copper. Dr. Lalancette has published a handy guide for copper applications in early covers. Antibiotics such as Mycoshield or Fireline may also be used and may offer slightly more residual activity during long wetting periods. Bacterial Spot leaf symptoms have began appearing in southern county orchard during the week of 5/8. These infections probably occurred mostly during the heavy rains that occurred on 4/30-5/1. Fruit symptoms from this set of infections have so far not appeared. This week no significant increase in symptoms was noted.

Oriental Fruit Moth: A biofix point for OFM was set on 4/10 in both northern and southern counties.  All timings for first generation OFM have past.

OFM 2nd Generation Timing
Insecticide Type
County/Region Degree Days by  5/24 base 45 Conventional

1450-1500

 Diamide

1300-1400
Gloucester – Southern 603 1st –too far off

2nd – too far off

 1st –too far off

2nd – too far off
Middlesex – Northern 578 1st –too far off

2nd – too far off

 1st –too far off

2nd – too far off

Plum Curculio; Tarnished Plant Bugs; and Other Catfacing Insects: Plum Curculio start to move into orchards at about 88-100 degree days base 50 after January 1. Applications for PC should be initiated once all petals are off, with a second application made with ovicidal materials at 379-402 DD. Additional applications with effective materials may be made between 520 and 730 DD base 50. Currently we have accumulated about 498 DD base 50 in southern counties, and 426 DD base 50 in northern counties. Growers can monitor degree day development at their site by finding the nearest weather station and using the degree day development tool at NEWA. Catfacing insects are active, but will become more of an issue as temperatures warm and mowing and other ground cover activities become more common.

Scale Insects: White peach scale crawlers have begun emergence in southern counties and will continue emergence for the next few weeks. San jose scale crawlers typically begin emergence about late May or Early June and continue emergence for up to 6 weeks. Control options during crawler emergence include Neonicitiniods (suppression only), and the IGR’s Esteem and Centaur. See the NJ Commercial Tree Fruit Production Guide and the product labels for more information.

Apples and Pears:

Diseases: Now that primary scab is nearing the end, or has ended, the focus turns toward summer diseases such as fruit rots (esp. Bitter rot), and sooty blotch and fly speck. Bitter rot control has been difficult at best in recent years even where management programs have been rigorous. Research has suggested Products such as Merivon, Luna Sensation and Inspire Super may be effective, and longtime reliable broad spectrum fungicides such as captan and ziram should provide control. Experience has suggested that the addition of phosphorous acid products such as Prophyt or Rampart to captan sprays may improve control. Observations are that these products improve control of other summer diseases such as sooty blotch and flyspeck, and may help suppress scab infections where present.

Fire Blight: Infections can still occur post bloom so covers with antibiotics when infection events are forecast using the NEWA fire blight model may be beneficial. Remember to rotate streptomycin and oxytetracycline products. Fire Blight symptoms began appearing in southern county apple and pear orchards the week of 5/1. Typically it is recommended to cut out infected limbs however this is a practical decision that must be made. This blog post from Michigan State may be helpful to decide whether it is worth cutting out infected tissue.

Codling Moth (CM): The first codling moth flight has started. A biofix was set for CM on April 17th in both northern and southern counties.

Codling Moth Degree Day Timing
Application and Insecticide Type
County Area Biofix Rimon:

75-100DD + 14-17 days later

 

 Intrepid

150 + 450 DD

Diamides – Altacor, Voliam mixes: (150-200 DD)

 Cyd-X, Carpovirusine

250 DD + every 7-9 days during brood hatch (later if first spray is an IGR)

 Standard Insecticides –  Delegate, Avaunt, OP’s, carbamates, pyrethroids

250 DD + 550 DD

 
DD 75 100 150 450 250 250 550
Southern April 17 past past past 6/4 5/21 5/21 6/7
Northern  past  past  past 6/6 5/23 5/23 6/11

Tufted Apple Budmoth (TABM): A biofix for TABM was set in southern county orchards on 5/8. Nothing needs to be done for TABM at this point. The first alternate middle applications for TABM will be on or about 6/3 in southern counties. This has been considered a minor pest in recent years. Many materials used for Codling Moth will also control TABM.

Pear:  Second generation pear psylla began hatching about 5/15. Options for control include spynosyn products such as Delegate and Entrust, and the neocitinoids (IRAC group 4A). The addition of 0.25-1 gal of summer oil may improve control. Other options include Movento, and products containing abamectin. Be sure to read and follow the label instructions regarding the addition of penetrants for these products.

Tree Fruit Trap Captures – Southern Counties

STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB
4/15/2023 433 20 1
4/23/2023 423 1 13 8 4
4/30/2023 417 7 15 4 1 0
5/06/2023 9 2 3 1 0 0
5/13/2023 18 2 7 2 3 0 6 6
5/20/2023 5 18 6 0 51 0 13 67

Tree Fruit Trap Captures – Northern Counties

STLM TABM-A CM BMSB OFM-A DWB OFM-P TABM-P LPTB PTB
4/8/2023 10
4/15/2023 20 3
4/30/2023 28 11 6
5/06/2023 22 2 19 9
5/13/2023 34 1 3 2 5 0
5/20/2023 31 6 7 1 6 0

Phenology Table: Based on annual observations made in Gloucester County.

Pest Event or Growth Stage Approximate Date 2023 Observed Date
 Bud Swell (Redhaven)  March 23 +/- 15 Days March 7
1/4″ Green Tip Red Delicious March 31 +/- 13 Days March 27
Pink Peach (Redhaven) April 4 +/- 15 Days March 24
Tight Cluster Red Delicious April 9 +/- 13 Days April 7
Full Bloom Peach (Redhaven) April 9 +/- 14 Days April 4
Pink Apple (Red Delicious) April 14 +/- 12 Days April 11
Full Bloom Apple (Red Delicious) April 22 +/- 11 Days April 16
Petal Fall (Redhaven) April 22 +/- 10 Days April 15
Petal Fall (Red Delicious) April 27 +/- 13 Days  May 3
Shuck Split (Redhaven) April 30 +/- 11 Days April 21
Pit Hardening June 15 +/- 9 Days

 

 

 

Filed Under: Tree Fruit, Uncategorized Tagged With: , , , ,