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Apple Pest Report:  Tuesday, April 19, 2005
 Vol. 13 No. 1

 

 

Greetings and Best wishes for the new growing season!  If your email reader doesn't accept the formatting of this newsletter, you can see it online at AppPestRept-2005-04-19.htm

 

 Scab  

     McIntosh trees in in Sanford reached green tip April 18.  This of course, brings with it susceptibility to apple scab infection.  Dr. Dave Rosenberger of Cornell University's Hudson Valley Lab is recommending a conservative, protectant approach to apple scab this year due to ever increasing concerns about resistance to post infection fungicides (SIs - Nova, Rubigan, Procure; strobilurins - Flint, Sovran).  While the resistance situation in Maine may not has progressed as far as Hudson Valley, we certainly share a heavy scab inoculum population coming from last year.

 

    Applying a protectant fungicide before the first rain after green tip will is the second step in preventing apple scab infection this year.  A first step would be to reduce inoculum load as much as possible.  Flail mowing, urea application can reduce the number of scab ascspores released into the air over the next 6-7 weeks.

 

    With a heavier than normal spore population, there is no need to wait to for spore maturity counts.  It's all a percentage game.  In a normal year we might wait until 15% of the ascospores appear mature before saying "It's scab season".  But the  scab ascospore population is a very variable number.  The difference between a "clean" and a "scabby" block can be literally a matter of 1000X more spores per square meter.  Given the wet spring last year and nagging scab levels that persisted into summer 2004, the scab level could easily be 10X or 100X what your orchard has typically had after an easier preceding scab year.  With that kind of potential magnification in the spore load, the percentage of ascospores that has to mature to create the same absolute infection risk becomes correspondingly smaller.  The bottom line is that green tissue equals scab infection risk in 2005.

 

   For details and discussion, there are two excellent articles by Dr. Rosenberger online at   http://www.cce.cornell.edu/scnyag/vegfruit/newslett/mar05.pdf

(see page 11 in the pdf file).

 

 

 

 Pest Management Guide Update  
 

2005 ‘Update’

to the 2003-04 New England Apple Pest Management Guide

L.P. Berkett, ‘Update’ Coordinator and Editor University of Vermont

 

Insect and Mite Management
Lorraine Los, University of Connecticut

Cancelled Product:
Dimethoate (Digon, Dimate) – The manufacturers have voluntarily withdrawn this product from use on several crops including apples. Growers may use existing stock in 2005.

New Products:

Calypso (thiacloprid): 4 lbs./gal F. Use 0.5 –1.0 fl. ozs/100 gals. for aphids, leafminers, leafhoppers and mirid bugs; use 1.0 – 2.0 fl. ozs./100 gals. for apple maggot, codling moth, European apple sawfly, oriental fruit moth, plum curculio and suppression of scale insects. Belongs to the neonicotinoid class of insecticides (as do Provado, Actara and Assail) and offers systemic activity. Comparatively safe on beneficials. Do not apply more than 16 fl. ozs. per acre per year. Allow at least 7 days between applications. Restricted entry interval 12 hours. Preharvest interval 30 days.

 

Cyd-X (codling moth granulovirus): 1-6 fl. oz. per acre. Aqueous suspension of an insecticidal granulovirus for control of codling moth. It must be ingested by larvae to be effective. At least two applications per generation are recommended; the first just before or at the beginning of egg hatch. The use of a spreader-sticker with UV blocking properties may extend the residual activity and enhance weather fastness. Use non-chlorinated water at a pH near 7 in the spray-tank mix. This material is certified by the Organic Materials Review Institute (OMRI) and approved for organic production. Restricted entry interval 4 hours. Cyd-X can be applied up to and including the day of harvest.
 

Decis (deltamethrin): 1.5EC. 0.9 – 1.9 fl. oz. per acre (depending on pest-see label). For leafrollers, leafminers, apple maggot, codling moth, Oriental fruit moth, plum curculio, leafhoppers, San Jose scale crawlers, plant bugs, aphids, and European apple sawfly. Do not apply more than 3.6 fl. ozs. per acre in one growing season. Highly toxic to bees exposed to direct treatment. Do not apply it or allow it to drift to crops or weeds on which bees are actively foraging. Extremely toxic to fish and aquatic invertebrates. Restricted entry interval 12 hours. Preharvest interval 21 days. Registration status may vary within the New England states.
 

Deliver (Bacillus thuringiensis, subsp. kurstaki) is another Bt product labeled for orchard use. As with other Bt products, its activity is primarily against early larval stages of fruitworms and leafrollers. Restricted entry interval 4 hours. Preharvest interval 0 days.


FujiMite (fenpyroximate): 5 EC. 1 – 2 pts. per acre. For European red mite, two spotted spider mites and white apple leafhopper. For resistance management, it should not be applied more than once per season, even though the label allows 2 applications per season. It should be rotated with products having a different mode of action where additional control is needed. Fujimite, Nexter and Kanemite have similar modes of action. Restricted entry interval 12 hours. Preharvest interval 14 days. Note: This product is also labeled for pear psylla control in pears. Registration status may vary within the New England states.

 

Kanemite (acequinocyl): 15 SC (suspension concentrate). 21 -31 fl. oz. per acre. For European red mite and two spotted spider mite. For resistance management, it should not be applied more than once per season, even though the label allows 2 applications per season. It should be rotated with products having a different mode of action where additional control is needed. Fujimite, Nexter and Kanemite have similar modes of action. Restricted entry interval 12 hours. Preharvest interval 14 days. Note: This product is also labeled for mite control in pears. Registration status may vary within the New England states.

 

Nexter is a new formulation of pyridaben which is the same active ingredient as Pyramite. It will replace Pyramite, which is being discontinued by BASF. Existing stock of Pyramite may still be used. The Nexter label has similar wording to Pyramite; however, Nexter can only be used once per season. The restricted entry interval and preharvest interval are the same for both products. Add the following to the Pyramite entry on Page 94 of the NEAPMG:

Nexter (pyridaben): 75% WS. 4.4 – 5.2 oz. per acre for European red mite; 8.8

– 10.67 oz. per acre for twospotted spider mite (TSM). Do not exceed 1 application per year. Restricted entry interval 12 hours. Preharvest interval 25 days.

 

Proaxis (gamma cyhalothrin): 0.5 lb./gal. CS (capsule suspension). 2.56 – 5.12 fl. oz. per acre. For aphids, apple maggot, codling moth, green fruitworm, Japanese beetle, leafhoppers, leafrollers, lesser appleworm, Oriental fruit moth, plat bugs, plum curculio, San Jose scale (fruit infestations), and leafminers. Highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Extremely toxic to fish and aquatic organisms and toxic to wildlife. See label for spray drift precautions when spraying in vicinity of aquatic areas. Do not apply more than 1.6 pts. per acre per year; no more than 1.28 pts. per acre per year postbloom. Restricted entry interval 24 hours. Preharvest interval 21 days. Registration status may vary within the New England states.

 

Warrior (lambda-cyhalothrin): 1 lb./gal. CS (capsule suspension). 2.56 – 5.12 fl. ozs. per acre. For leafrollers, internal fruit feeders, green fruitworm, leafminers, apple maggot, stink bugs, leafhoppers, plum curculio, Japanese beetle, plant bugs, periodical cicada, apple aphid, Rosy apple aphid, spirea aphid, and San Jose scale fruit infestations. Highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. See label for spray drift precautions when spraying in vicinity of aquatic areas. Do not apply more than 1.6 pts. per acre per year.; no more than 1.28 pts. per acre per year postbloom. Restricted entry interval 24 hours. Preharvest interval 21 days.

 

Zeal (etoxazole): 72% WDG. Miticide. 2.0 – 3.0 ozs. per acre. Effective against eggs and immature European red mite and twospotted spider mite. Not effective against adult mites. Does not control rust mites. Comparatively low toxicity to insect and mite predators. Maximum of 1 application per season. Restricted entry interval 12 hours. Preharvest interval 28 days.

 

Label Changes: In the 2003-2004 NEAPMG, we indicated that label changes were pending for Diazinon, Guthion and Imidan. The Guthion label (see below) has been revised, but Diazinon and Imidan labels remain the same for 2004 and 2005.

 

Actara – The 2004 label revision again includes use on apples produced east of the Mississippi River. The label also includes stone fruit. As you may recall, these were not on the 2003 Actara label. Other pome fruit such as pear, crabapples, loquat, mayhaw and quince also remain on the label.

There is also a new supplemental label for Actara, Supplemental Directions for Use on Pome Fruits: Pollinator Precautions. This Supplemental Label must be in the possession of the user at the time of pesticide application. Actara is highly toxic to bees exposed to direct treatment or residues on blooming crops. The supplemental label outlines correct timing for apples and pears, spray drift precautions, and other tactics to avoid contact to pollinators.

 

Assail -There is a new Supplemental Label for Assail which adds more target pests. The additional pests and rates include: 1.7 – 3.4 ozs. per acre for mullein plant bug and mealybug; 2.3 –3.4 ozs per acre for oriental fruit moth, European apple sawfly and Japanese beetle; and 3.4 ozs. per acre for apple maggot, plum curculio and San Jose scale (suppression only). The addition of a horticultural oil is recommended for improved performance especially for oriental fruit moth and San Jose scale. Note: Pear psylla is also on the supplemental label because the rate has changed to 1.7 –

3.4 ozs. per acre.

 

Avaunt -The Preharvest Interval has changed from 28 days to 14 days.

 

Guthion – Guthion will now only be sold as Guthion Solupak 50% which is a water soluble packet. Growers may use up their existing stock of older product according to original label directions.

 

     The following significant changes have been made to the Guthion Solupak 50% label for apples.

* Maximum allowable use is 8 pounds of Guthion Solupak per acre per year.

* The restricted entry interval is 14 days, but is reduced to 7 days for fireblight pruning (provided workers are thoroughly protected as per label).

* Preharvest interval is 14 or 21 days. 14 days if the last application does not exceed 2 pounds per acre. Otherwise, 21 days.

* The re-entry for the general public into Pick-Your-Own blocks is 30 days.

* There is new language with regard to reducing spray drift, especially to protect

aquatic habitats. There is a list of 12 “Requirements for Reducing Spray Drift”. This includes restrictions on wind speed (Apply only when the wind speed is less than 10 mph) and applications near water (Do not apply within 25 feet of permanent water bodies). Review this entire list before applying Guthion.

 

Note: The new Guthion label does not include plums. The tree fruit crops listed include apples, crab apples, pears, cherries, nectarines, and peaches.

 

 

Lorsban – A new formulation, Lorsban 75WG (water dispersible granule), will replace Lorsban 50W, which is being phased out. It is described as an encapsulated “dry EC” and is a low-odor material. Currently, it is only labeled for pre-bloom use on apples.

 

 

Other Insecticide Corrections:

There is a typo on the Lorsban 50W rate for dogwood borer trunk sprays on Page 139. The rate for Lorsban 50WP should be 1.5 lbs. per 100 gals. However, this formulation is being phased out (see above).

 

 

Disease Management

Daniel Cooley, University of Massachusetts

 

Agri-Fos (phosphorous acid): 46%. See phosphorous acid.

 

Agri-Mycin 17, Bac-Master (streptomycin sulfate): streptomycin sulfate. Agri-Mycin 17 is a 17 WP (4–8 oz/ 100 gal, see label for other rates); Bac-Master is a 17% product as well, but labeled in ppm (50 – 100 ppm = 4-8 oz/100 gal). Bactericide used to prevent fire blight. Effective if used the day before, or the day of, a fire blight infection period. Where fire blight is expected to be a problem, the first spray is made after the first blossoms open when weather conditions favorable for the disease are present or predicted within 24 hours. Must be absorbed by the blossoms to be effective, should not be applied just before or during rain. The frequency of repeat applications depends on weather, blossom opening and disease pressure. Routine use to control shoot blight is not recommended. However, application within 24 hours after the beginning of a hail storm is recommended for fire blight-threatened orchards. Thorough coverage is essential for control. Application at concentration greater than 6X is not recommended. Restricted entry interval 12 hours. Preharvest interval 50 days.

 

Agrisolutions Topaz (phosphorous acid): 53%. See phosphorous acid.

 

Aliette (fosetyl aluminum): 80% WDG or 80% WSP. Foliar application for control of Phytophthora crown and root rot on bearing and nonbearing apple trees and blister spot on fruit. Also labeled for control of fire blight, but is not recommended for that purpose. The material is absorbed by the foliage and transported to the roots. Avoid conditions that limit leaf absorption. Adjuvants which enhance pesticide penetration may cause phytotoxicity when mixed with Aliette. Do not apply within 2-3 weeks of leaf senescence on bearing trees. Under moderate disease pressure, apply 3 to 4 times at 5.0 lbs./100 gals. at a 60 day spray interval, or at 2.5 lbs./100 gals on a 30 day interval. Use no more than 5 lbs. Aliette per acre. Do not exceed 20 lbs. Aliette per acre per season. Should not be used as a season-long solution to wet soils which can lead to Phytophthora root rot, but rather as a way to maintain production until longer term solutions such as drainage or raised beds can be installed. Do not tank mix with copper compounds. If used prior to or after copper applications, adjust pH to 6.0 or above with an alkaline buffer such as potassium carbonate. Restricted entry interval 12 hours. Preharvest interval 14 days for Bearing trees; 12 months for Non-Bearing trees.

 

Allude (phosphorous acid): 45.8%. See phosphorous acid.

 

Apogee (prohexadione calcium): 27.5%. (6-12 oz/100 gal). Growth regulator that reduces shoot growth and reduces fire blight infections on shoots. Should only be used in those blocks with a history of fire blight, as applications need to be made when shoots are 1 to 3 in., which is before shoot symptoms generally show. Apogee has no effect on blossom blight, and no antibiotic activity. Instead, it makes the apple tissue less susceptible to fire blight. Refer to label for rates.

AS 50: see Agri-Mycin.

 

Bac-Master: see Agri-Mycin.

 

Bordeaux Mixture: a mixture in water of copper sulfate (bluestone) and hydrated spray lime used as a spray for fire blight. A good mix for apples is Bordeaux 10-10-100. The first number of the Bordeaux formula is lb copper sulfate, the second is the lb spray lime, and the third is gal water. The mixture is prepared by dissolving copper sulfate snow (not fixed copper) in about 1/2 tank of water. Once the copper sulfate is completely dissolved, the spray lime is added slowly with constant agitation, and the tank is filled with water. Bordeaux mixture is generally unsafe to use on apples after the 1/4-inch green stage, as it can cause severe russet on fruit and damage leaves. Adding 1 qt spray oil per 100 gal reduces the chance that Bordeaux will accumulate on foliage edges and burn leaves.

 

Captan: The Captan 80WDG from MicroFlo has a 24 hour re-entry period for apples. Other captan products still have a 96 hr. re-entry period. Read the label carefully to determine the restricted entry interval for the product you are using.

 

coppers: Use as an early season scab protectant and as a bactericide to reduce the population of fire blight bacteria. Generally these products are too phytotoxic and cause significant fruit russet if applied after ¼ in. green. Some formulations are labeled for use as a drench to prevent Phytophthora crown rot, but efficacy for this has not been evaluated. Sold under many trade names and formulations. Types include copper hydroxide (Champ, Champion, Kocide), copper oxychloride sulfate (COCS), and basic copper sulfate (Basic Copper 53, Cuprofix Disperss, Basicop, Blue Shield). These formulations are called “ fixed,” because the copper ion is relatively insoluble and less phytotoxic than in other coppers, such as copper sulfate (bluestone) used in Bordeaux mix. Application must be made as early as possible, no later than full green tip due to fixed copper’s ability to damage young foliage or cause russeting on fruit. To further reduce russeting, use the lowest labeled rate of copper. See specific labels on adding hydrated lime to the tank-mix to reduce crop injury. Restricted entry interval 24 hours for Basic Copper 53, Basicop, Champ, Champion, COCS, Cuprofix Disperss and Kocide.

 

Fosphite (phosphorous acid): 53%. See phosphorous acid.

 

Messenger (harpin protein): a biological pesticide that stimulates the plant’s pest resistance systems. It does not directly attack pathogens. Messenger has shown variable efficacy against fireblight . It takes 5 – 7 days after application for the plant to develop resistance. Do not use with chlorinated water, or at pH below 5.0 or above 10.0.

 

OxiDate, StorOx (hydrogen dioxide): similar to hydrogen peroxide, kills fungi, bacteria and other microbes it contacts. OxiDate is labeled for use in the field, StorOx for use in post-harvest treatments. Field applications to apples are not recommended because the product can severely russet fruit.

 

Phosphorous acid: Comes in several formulations and concentrations including Agri-Fos, Agrisolutions Topaz, Allude, Fosphite, Phostrol and Phos-Phyte. Foliar applications for control of Phytophthora crown and root rot on apples. Also labeled for scab control and fire blight, but these uses are not recommended because efficacy is not high. For crown and root rot, foliar applications should be made at 30 to 60 day intervals. Application rates of 1 1/4 to 2 1/2 quarts per acre, applied in water sufficient to wet foliage and allow uptake of the material. Where disease pressure is high, use the higher rates and shorter intervals. This material is very similar to fosetyl-Al (see Aliette).  Restricted entry interval 4 hrs. Preharvest interval 0 days.

 

Phostrol (phosphorous acid): 53.6% solution of phosphorous acid and ammonium phosphite. See Phosphorous acid.

 

Pro-Phyte (phosphorous acid): 54.5%. See phosphorous acid

 

Scala (pyrimethanil): As of the date this is written, Scala was not registered in Massachusetts, though it has cleared EPA registration. 54.6% SC. Scala is a new fungicide, an anilinopyrimidine with the same type of activity as Vangard. Risk of resistance development is rated medium, and there is some evidence that resistance to DMI fungicides (Nova, Rubigan, Procure) also transfers to anilinopyrimidines. It is therefore recommended that Scala be tank-mixed with captan, an EBDC or another broad-spectrum fungicide. Do not exceed 5 applications per season. In a tank mix, Scala is recommended at 5 fl oz/A. Restricted entry interval 12 hr. Preharvest interval 72 day. Registration status may vary within the New England states

 

Serenade (Bacillus subtilis): a biological control bacterium labeled for control of fire blight, scab, and powdery mildew. Serenade alone has not proven effective against these diseases. However, it has shown good activity against fire blight when used in alternating applications with streptomycin, and some activity against scab when used in alternating applications with other fungicides. Serenade has low activity against fungal diseases in New England conditions. It should be used as a preventative.

 

Topsin M, Thiophanate Methyl (thiophanate methyl) : Formulated as a 70W WSB, 85 WDG or 4.5 FL. While rates for the 70% formulation are the same as previously described, rates for the 85% are labeled at 3.2 oz. to 4.8 oz. per 100 gal., and the 4.5 FL rates are 3.5 fl. oz. to 5 fl. oz. per 100 gal.

 

 

Other Disease Management Corrections:

Page 129 (and subsequent pages): “ Dilute” defined on page 128, not on p. 126 as indicated.

Page 88, Table 14: Please note that mancozeb products have a 77 day preharvest interval.

 

 

 

Weed Management

Jon Clements, University of Massachusetts


New Product:

Chateau Herbicide WDG: a contact and residual herbicide that controls both grasses and broadleaf weeds in NON-BEARING orchards (365 days pre-harvest interval). Therefore, it is only useful in young orchards. Note that it can be used the year-of-planting if trees are shielded, and it can be used on apples and all stone fruit. It is most effective as a contact herbicide on very young weeds, but it is recommended to apply in a tank mix with another contact herbicide for maximum effectiveness. It appears to be a very effective residual herbicide. Application rate is 6-12 oz per treated acre, using the lower rate on sandy soil. Restricted entry interval 12 hours. Preharvest interval 365 days.


Addition to Notes on Herbicides, page 119: The statement "For non-bearing apples only." should be added to Fusilade.

 

Always read the label before using any pesticide. The label is the legal document for the product use. Disregard any information if it is in conflict with the label.

 

 

 

 

 Insects and Mites

    It's not too early to apply oil to smother overwintered Europen red mite eggs.  Use a 2% rate (= 2 gallons of oil for every 100 gallons water) for oil appliations up to half inch green, then decrease the amount of oil to 1.5% for applications up to tight cluster, and use only 1% from tight cluster to early pink.  Even a single oil applicatoin can prevent ERM problems for the rest of the season where pressure is light.  Two applications increases the odds for preventing the need for a summer rescue treatment.  Captan and oil should not be applied within 7-10 days of each other.  A 7-day separation should be adequate unless there is an abscence of rain in the interim. 

 

 

    

 Scouting Co-op
 

    With support from the Maine State Pomological Society, Cooperative Extension will again be providing an apple scout to provide independent observations of scab, mites and other pests in orchards of 1 acre or more.

 

    We still have about 10 grower slots available for 2005.  If you would like to be included in the scout co-op, please send an email to me at gkoehler@umext.maine.edu


 

Sincerely,                                            
Glen

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PEST MANAGEMENT OFFICE | UMCE HOMEPAGE | UMAINE

Putting Knowledge to Work with the People of Maine
 Glen W. Koehler
Associate Scientist IPM
Voice: 207-581-3882 (within Maine: 800-287-0279)
Email: gkoehler@umext.maine.edu
Pest Management Office
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