WVU Extension Service: The Orchard Monitor: Committed to the Integration of Orchard Management Practices
March 20, 2006

Upcoming Events Grower Meeting Sponsors Spray Bulletin Entomology Plant Pathology



April 4, 6:00 p.m. - Tree Fruit Grower Twilight Dinner and Meeting at the WVU Kearneysville Tree Fruit Research and Education Center, Kearneysville, W. Va.  Extension Specialists will discuss early-season insect and disease management strategies. For more information contact the WVU KTFREC at 304-876-6353.  


The following fruit industry support companies and representatives have contributed to a Grower Meeting Fund to cover expenses at fruit schools and grower meetings.  Please let them know that you appreciate their support as we do.

Adams County Nursery, Inc. - Phil Baugher
Bayer CropScience - Rick Love
CBC (America) Corp. - Greg Stamm
Dow AgroSciences - Patti Schurr
Durand-Wayland, Inc. - Ron Shrum
Knouse Foods Coop., Inc. - Dave Cox
Syngenta Crop Protection, Inc. - Ryan Lins
UAP - Larry Dell
Winchester Equipment Co. - Doug Rinker


The 2006 Virginia/West Virginia/Maryland Spray Bulletin For Commercial Tree Fruit Growers may be picked up at the WVU KTFREC or obtained by mail for $10.00 each.  A check (payable to West Virginia University) should be sent to the WVU KTFREC, PO Box 609, Kearneysville, WV 25430-0609.


Ten new products, eight of which are listed in the 2006 Spray Bulletin for the first time, have become available for arthropod pest management in tree fruits.  The two products not listed were registered after the Spray Bulletin went to press last fall.

Three new insecticides are pyrethroids.  Decis (deltamethrin) is a 1.5EC from Bayer CropScience registered for the control of over 20 foliage and fruit-feeding insects on apple and pear.  It is rated good or excellent against all pests, except for fair to good against spirea aphids.  Application rate is 0.9-1.9 fl oz per acre (varies with pest) with a maximum of 3.6 fl oz per acre per season.  Decis has a 12 hour restricted-entry interval (REI) and 21 day preharvest interval (PHI).  Application timings listed in the Spray Bulletin are -inch green to prepink on apple and green cluster bud to white bud on pear.  Battalion (deltamethrin) is a 0.2EC from Arysta LifeScience that is registered for the same insects as Decis on apple and pear.  Although not yet rated or listed in the Spray Bulletin, performance of Battalion is expected to be similar to Decis.  Application rate is 7.0-14.1 fl oz per acre (varies with pest) with a maximum of 26.9 fl oz per acre per season.  Battalion has a 12 hour REI and 21 day PHI, and is recommended for prebloom use only.  Baythroid (cyfluthrin) is a 2EC from Bayer CropScience registered for the control of numerous pests on apple, pear and stone fruits.  Although not yet rated or listed in the Spray Bulletin, performance is expected to be good to excellent against most pests.  Application rate is 1.4-2.8 fl oz per acre (varies with pest), with a maximum of 2.8 fl oz per acre per season on pome fruits and 5.6 fl oz per acre per season on stone fruits.  Baythroid has a 12 hour REI and 7 day PHI.  It is recommended for use during the prebloom period on pome fruits and through petal fall on stone fruits.  Use of any of the above three pyrethroids after bloom on pome fruits or after petal fall on stone fruits (Baythroid) is more likely to cause outbreaks of mites and other secondary pests such as woolly apple aphids.

Clutch (clothianidin) is a 50WDG neonicotinoid insecticide from Arysta LifeScience registered on apple and pear for the control of aphids, leafhoppers, leafminers, plum curculio, apple maggot, codling moth, oriental fruit moth and pear psylla.  Application rate is 2-6 oz per acre (varies with pest), with a maximum of 6.4 oz per acre per season.  Clutch is rated excellent for aphids, leafhoppers and leafminers; good for pear psylla; but only fair for codling moth and oriental fruit moth.  It has a 12 hour REI and 7 day PHI, and is listed in the Spray Bulletin from petal fall to eighth cover on apple and from petal fall to fifth cover on pear.

Centaur (buprofezin) is a 70WP insect growth regulator from Nichino America, Inc. registered on apple, pear and peach for the control of scales, leafhoppers and pear psylla.  It acts as a chitin biosynthesis inhibitor (disrupts molting) and, therefore, has primary activity on the nymphal stages of these pests.  Although adult insects are not controlled, there is some reduction in egg laying and viability of eggs.  Insect uptake of Centaur is primarily through contact with some vaporization for a period of time after application.  It is rated excellent for the control of San Jose scale and leafhoppers.  Application rate is 34.5 oz per acre with a season maximum of one application on apple and two applications on pear and peach.  Centaur has a 12 hour REI and 14 day PHI, and is listed in the Spray Bulletin at second and third cover and from fifth to eighth cover for the control of San Jose scale crawlers on apple.

Rimon (novaluron) is a 0.83EC insect growth regulator from Makhteshim-Agan of North America registered in West Virginia under a Section 24 (c) supplemental label for the control of codling moth, oriental fruit moth and leafrollers on apple.  Because it acts as a chitin biosynthesis inhibitor (disrupts molting), primary activity is against the larval stages of the above pests.  However, there is some toxicity to eggs, especially when laid on treated surfaces.  Route of insect entry is primarily through ingestion with some contact activity.  Rimon is rated excellent for codling moth and leafrollers, and good for oriental fruit moth.  Application rate is 20-40 fl oz per acre with a maximum of four applications (150 fl oz per acre) per season.  It has a 12 hour REI and 14 day PHI.  Rimon is listed in the Spray Bulletin from petal fall to eighth cover, but for a given insect generation applications should be initiated at the beginning of egg laying for codling moth and oriental fruit moth, and at the beginning of egg hatch for leafrollers.  Use of Rimon has resulted in increases in mite populations, which have been more severe following early season use.

Carpovirusine is a 1% granulosis virus from Arysta LifeScience registered for the control of codling moth on apple and pear.  It has activity against the larval stages through ingestion and is rated good.  Larvae are killed in 3-7 days, depending on dosage and temperature.  Application rate is 1 pint per 100 gallons.  Carpovirusine has a 4 hour REI and 0 day PHI.  At least two applications per generation (10 days apart), initiated at the beginning of egg hatch, are recommended for codling moth control.  The product should be stored in a refrigerator, or frozen if stored for more than one year then thawed in refrigerator.

Isomate CM/OFM TT is a twin tube pheromone dispenser from Pacific Biocontrol Corporation registered for mating disruption of codling moth and oriental fruit moth in apple, pear and stone fruits.  Dispensers should be installed during bloom of apple (for first codling moth flight) in the upper third of the tree canopy at a rate of 200 per acre, with 400 per acre on orchard edges.  Dispensers will provide full season mating disruption control of codling moth and 90-100 day control of oriental fruit moth.  Isomate CM/OFM TT has a 0 hour REI and 0 day PHI.  It is recommended for use in square blocks of at least 5 acres in low to moderate pressure.  High pressure situations should be supplemented with insecticides.  Performance should be monitored with pheromone traps and by inspection of fruit for injury.

CheckMate OFM-F is a 23.6% liquid pheromone from Suterra registered for the mating disruption of oriental fruit moth on apple, pear and stone fruits.  Rated as excellent, the product should be applied at 1.3-2.9 fl oz (39-87 ml) per acre, with a maximum of 22 fl oz (649 ml) per acre per season.  Initiate application at the beginning of moth flight as determined with pheromone traps and retreat as needed based on moth capture.  Monitor product performance with pheromone traps and by visual inspection for terminal and fruit injury.  Supplemental insecticide applications may be needed in high pressure situations.  Use in sprayers equipped with piston, diaphragm, or centrifugal pumps only.  Do not use in sprayers equipped with roller or gear pumps as they will damage the product's controlled release system.  CheckMate OFM-F is listed in the Spray Bulletin from first to eighth cover on apple and from first to fifth cover on peach.  It has a 0 hour REI and 0 day PHI.

Envidor (spirodiclofen) is a 2SC miticide from Bayer CropScience registered on apple, pear and stone fruits for the control of European red mite, two-spotted spider mite, apple and pear rust mites, and peach silver mite.  Acting as an insect growth regulator by inhibiting lipid biosynthesis, Envidor has activity against mite eggs, immature stages and adult females, but not adult males.  Application rate is 16-18 fl oz per acre with a maximum per season of one application (18 fl oz/acre).  Minimum application volume (ground application only) is 50 gal per acre on stone fruits and 100 gal per acre on pome fruits.  Envidor has a 12 hour REI and 7 day PHI.  It is rated excellent and listed in the Spray Bulletin during cover sprays on all tree fruits.  Due to its insect growth regulator properties, Envidor should be applied on a preventive basis or at a low mite threshold, with performance evaluation conducted 4-10 days following application.

Pear psylla adults overwinter in or near pear orchards.  When daytime temperatures exceed 50F, adults return to pear trees, mate and begin laying eggs (pale cream to yellow-orange colored) in crevices on fruit spurs.  The use of oil during the dormant to white bud stage delays egg-laying because females do not like to lay eggs on oily surfaces.  Oil application shortens the length of the egg-laying period, resulting in a population with a more uniform age structure which makes management easier.  Oil can be used from dormant to the white bud stage, but the rate should be gradually reduced from 3% (dormant) to 2% (green cluster bud) to 1% (white bud).  An effective strategy is to make two applications of oil at 2% each, the first at dormant to bud swell and the second at the green cluster bud stage.  An insecticide to kill adults should be combined with oil, especially with the second of two oil sprays.  A pyrethroid (Asana, Ambush, Danitol, Decis, Pounce, Proaxis, Warrior) is a good option to combine with oil.  Actara, Assail, or Calypso at green cluster bud, or Esteem, Assail, or Calypso at white bud are also  excellent options for prebloom psylla control. Three prebloom applications (dormant-green tip, green cluster bud and white bud) of Surround have also provided very good control of overwintering adults.  Surround should not be tank-mixed with oil.

Pear psylla adult

Pear psylla eggs

San Jose scale fruit injury

If injury from San Jose scale was detected on fruit at harvest last season, a dilute application of oil, Lorsban, Supracide or Esteem is recommended from the green tip to -inch green stage of bud development.  Oil will also provide control of overwintering eggs of European red mite, and will typically maintain mite populations below threshold into June when applied at 2 gal/100 gal dilute at the green tip to -inch green stage, or 1 gal/100 gal dilute at the tight cluster stage.

European red mite overwintering eggs

Pheromone traps should be installed at this time for monitoring of Redbanded leafroller, and the beginning of April for monitoring of Oriental fruit moth.


Diseases of concern for the next two weeks.  Apples: Fire blight, apple scab; Stone fruits: leaf curl (covered in the previous newsletter).

Fire blight.  Fire blight bacteria overwinter in cankers, often at the ends of pruning cuts where blight strikes were cut in the previous season. A good way to reduce the risk of a severe fire blight outbreak is to make a late dormant application (no later than 1/4 inch green on fresh-market fruit) of a copper-containing material (i.e. Bordeaux mixture, C-O-C-S, Kocide, Tenn Cop 5E, just to name a few) that acts to kill a large percentage of the bacteria on the plant surface (and provides some early-season protection against apple scab). Although this spray does not eliminate the possibility that fire blight could become epidemic this year, in some years it may reduce considerably the amount of inoculum available for blossom infections. The effectiveness of the treatment may depend on how much rain we receive in the pre-bloom period. This dormant application is recommended where fire blight was present last year and on young trees of susceptible apple cultivars such as Gala, Fuji, York, Jonathan, and Rome Beauty (whether fire blight was present last year or not), or on any cultivar on M.9, Mark, and M.26 rootstock.

Given that the bacterium moves easily from unsprayed blocks to adjacent sprayed blocks, it may be useful to apply copper to blocks (or rows) of less susceptible trees that are adjacent to blocks of more susceptible trees. Most copper formulations are compatible with oil. Streptomycin should be applied to blossoms of susceptible apple and pear cultivars when weather conditions favor infection.

There is additional information on fire blight biology and management in the Spray Bulletin. Monitor our WWW Site for up-to-date information on the disease.

Apple scab ascospores should be abundant this spring. Look for apple scab ascospores to mature near the green tip stage of bud development. This means that if you had greater than 0.5% leaf infection when you assessed foliage prior to leaf fall last season, then you should be ready to spray for the earliest scab infection periods. It is important to avoid early infections on sepals, as these are difficult to detect and can provide conidial inoculum throughout the early part of the growing season. Where pre-leaf fall leaf assessments indicated 1% or higher leaf infection, sanitation practices (urea application or flail mowing leaf litter) are unlikely to delay the onset of significant scab infection, and early spraying is advised.

Phytophthora root rot can be managed with mefanoxam (Ridomil Gold EC and Ridomil 5G) and will aid in the control of crown, collar, and other root rots caused by Phytophthora spp. on both bearing and non-bearing apple trees. Ridomil 5G can be used in nonbearing orchards only. Applications should be made on a preventative schedule before symptoms appear, especially in orchards where conditions are favorable for disease development. For best results, make one application at the time of planting or in the spring before growth starts. Make another application in the fall after harvest.

Dipping the roots of nursery-grown trees into a solution of the fungicide Aliette prior to planting may reduce inoculum on infested rootstocks. To use, thoroughly mix Aliette at a rate of 3.0 lbs./100 gallons of water, in the desired volume of water and dip the entire root system for 30 to 60 minutes in the mixture prior to planting in the field.


Trade and brand names are used only for the purpose of information, and the West Virginia University Extension Service does not guarantee nor warrant the standard of the product, nor does it imply approval of the product to the exclusion of others which may also be suitable. The West Virginia University Extension service assumes no responsibility in the use of hazardous chemicals.

Individuals requesting an accommodation at an Extension Meeting because of a disability should contact one of the Specialists at the WVU Tree Fruit Research and Education Center at 304-876-6353 at least 5 days prior to the meeting date.

Helping you put knowledge to work

P. O. BOX 609
PHONE:  304-876-6353
FAX:  304-876-6034
WEB:  www.caf.wvu.edu/kearneysville/wvufarm1.html

The West Virginia University Cooperative Extension Service, U.S. Department of Agriculture, West Virginia County
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