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Healthy Fruit 2009 Vol. 17:5

May 5, 2009

Current (May 3) degree day (DD) Accumulations

Location: UMass Cold Spring Orchard (CSO), Belchertown, MA

  • Base 43: 365
  • Base 50: 188

Significant upcoming orchard events based on degree days (Base 43):

  • lesser appleworm 1st catch: 253–531
  • spotted tentiform leafminer sap-feeders present: 343–601
  • McIntosh at bloom: 349–421
  • Oriental fruit moth 1st flight peak: 344–542

Current bud stages

McIntosh apple --
Bartlett pear --
early petal fall
PF-14 Jersey
peach -- petal fall
Cavalier sweet cherry -- bloom


McIntosh Apple Bloom Bartlett Pear Petal Fall Jersey Peach Petal Fall Cavlier Sweet Cherry Bloom

The way I see it

I proclaimed Monday, May 4, McIntosh bloom at the UMass Orchard in Belchertown. Honeycrisp is at king bloom and beyond. Gala is at 1st king bloom. Some peaches are at petal fall, and cherries, well, it depends. See my pictures of current bud stages here. Many thanks to all those who contributed to my request to submit your bud stages here. It seems the majority of Massachusetts should be in bloom about now, notable exceptions being the Berkshires and immediate coastal locations. (Although the latter are not far behind.)

Most escaped the fireblight bullet last week as it cooled down sufficiently before bloom opened up. Some orchards may have had some open bloom mid-week last week, and then a strep spray was warranted. As of right now, the fireblight risk appears minimal as we move into the thick of bloom. But the weather forecast changes daily, so be prepared to apply a strep spray if you are in bloom and you get at all 'sweaty' with moderate physical activity.

My feeling is the overall dry weather pattern has made scab pretty manageable. It is suppose to be wetter this week, so, I am betting one or more fungicide applications within a 7-10 day period will be warranted. No new news there.

The petal-fall 'bug' edition of Healthy Fruit will most likely be next week.

Finally, I am pretty excited about the recently launched NEWA Apple Disease Models and NEWA Apple Insect Models found on the NEWA website for Massachusetts. I am not going to go into much explanation here, so I hope you visit them and investigate. Right now, you can choose a nearest airport location and produce model output for various disease (apple scab and fireblight) and insect (codling moth, Oriental fruit moth, obliquebanded leafroller, plum curculio, spotted tentiform leafminer, and apple maggot) pests. I foresee a day very soon when these models will be specific to your orchard. Stay tuned.

J. Clements


UNH Tree Fruit Twilight Meeting

Those of you in the northeast corner of MA might be interested in attending the University of New Hampshire Tree Fruit Twilight Meeting for Commerial Fruit Growers at the UNH Woodman Horticultural Research Farm in Durham (70 Spinney Lane) on Wednesday, May 13, 2009 from 5:30 to 8 PM. In particular, a guest speaker will talk about Native Insect Pollinators. Two pesticide re-certification credits are available, however, you MUST be on time (5:30). For more information, call George Hamilton, 603-641-6060.

J. Clements

Healthy Fruit Disease Elements

The mid-season scab report

It's the middle of scab season, and the middle of a showery, wet period. In short, now is the time to use full rates of the best fungicides available. Where you don't feel SI resistance is an issue, then Inspire Super, Indar, Rally, or Rubigan with a protectant (mancozeb or captan) is the best choice. If resistance to SI fungicides is a concern, then a strobilurin (Sovran or Flint) should be substituted for the SI.

Rusting in the rain

The extended rain at this time is also ideal for rust infections. I've had some discussion about rust diseases lately, and while we generally don't have big rust problems in our region, here is a word of caution. A mid-western grower recently commented that he had never had rust problems, but last year had developed a real rust outbreak. He had switched over from using a pro-longed SI plus mancozeb program to using only two SI plus captan sprays, with Polyram used early (before bloom), then captan and a strobilurin later. At least in part, the outbreak may have been caused by reliance on captan plus the strobilurine in petal fall and later sprays. Neither type of fungicide is effective against the rusts. On the other hand, mancozeb and SI fungicides are very effective rust materials.

Another point worth noting is to remember that by staying below a 3 lb/A rate on mancozeb, these fungicides can be used after petal fall. That should be adequate to deal with any rust issues.

A very close call on fire blight

The instant heat last week quickly drove up fire blight inoculum. But, as Jon Clements pointed out, the heat didn't drive tree development quite fast enough to generate a high risk of infection. Still, it would not surprise if a few fire blight strikes are found in blocks that have a history of recent fire blight and that had some bloom on Friday.

By Sunday, cold nights and cool days meant that the population of fire blight bacteria dropped, and fire blight risk is now low.

New web tools for apple IPM

There are some new weather-based web tools available to MA growers on the web. The top link below will connect you to either a disease (scab and fire blight) monitoring page, and the bottom one will connect you with an insect (curculio, codling moth, other leps, and apple maggot) monitoring page. The pages give predictions of activity and risk, based on models that are driven by weather data.

Cornell University NEWA webpage

At present, the data comes from National Weather Service sites, mostly at airports, in MA. You can select the site nearest to your orchard, and select dates of interest. In the near future, Jon Clements and I hope to bring weather stations that are at orchards into the system.

Perhaps more interesting, we are working with Cornell to also link the weather and pest forecasts to management recommendations. This would give options for treatments adapted to the particular time, risk and grower preferences. We'll provide more info as these features become available.
D. Cooley

Guest article

Editors note: Lorraine Los, my colleague at UConn who works in fruit has generously prepared an excellent update to pesticide label changes and new pesticides for fruit crop. I am re-printing it here in it's entirety with her permission. I hope you find it as useful as I do. Also be aware that not all new pesticides may have received state registration yet. Check with your agri-chemical supplier.
J. Clements

Pesticide Label Changes and New Pesticides for Fruit Crops

Lorraine Los, University of Connecticut

Changes to Existing Pesticide Labels


Guthion (azinphosmethyl)
The only remaining tree fruit uses include apples, pears and cherries, which are supposed to remain on the label until 2012. The current Guthion Solupak 50% label includes maximum use rates for years 2008-2012. These rates change depending on year and crop. For 2009, the maximum use rate is 6.0 lbs. formulation per acre per year for apples; 4.0 lbs. formulation per acre per year for pears; and 3.0 lbs. formulation per acre per year for cherries. The REI is 14 days for apples and pears and 15 days for cherries. The preharvest interval (PHI) is 14 or 21 days for apples and pears (depending on rate) and 15 days for cherries. "Pick-Your Own" harvesting is prohibited on pears and cherries if Guthion is used. On apples, the REI for "Pick Your Own" varies from 33 to 44 days, depending on rate used. There are also restrictions regarding spray drift and buffer zones for water bodies. Be sure to read this label very carefully!

Lorsban (chlorpyrifos)
There has been a lot of confusion regarding the use of Lorsban (chlorpyrifos) and the various generic chlorpyrifos products, particularly for use on apples.

Lorsban 4E (Dow) can be used on apples in one of 3 ways: as a single foliar spray dormant/delayed dormant OR as single trunk spray dormant/delayed dormant OR as a single trunk spray post-bloom. No petal fall or post-bloom foliar sprays are allowed. The post-bloom trunk application of Lorsban 4E is now on the main label so you don't need a supplemental label for this formulation anymore. Only 1 application of Lorsban 4E is allowed on apples per year. Restricted Entry Interval (REI) = 4 days.

Lorsban Advanced (Dow), which is supposed to be a low-odor formulation, can be used on apples as a single foliar spray dormant/delayed dormant OR as single trunk spray dormant/delayed dormant. No petal-fall or post-bloom applications (foliar or trunk) are allowed. Only 1 application of Lorsban Advanced is allowed on apples

Lorsban 75 WG (Gowan) can be used on apples as a single foliar spray dormant/delayed dormant OR at petal fall. One additional application of Gowan's Lorsban 75WG can be made on apples post-bloom as a trunk spray. You are limited to a maximum foliar application of 2.67 lb. per acre of Gowan's Lorsban 75WG per year. However, this seasonal limit does not include the trunk spray, used at a rate of up to 2 lb. per 100 gal. of the Lorsban 75WG. 2 applications of Lorsban 75WG allowed on apples per year on the current label. Restricted Entry Interval (REI) = 4 days. Note: We expect more label changes for Lorsban 75 WG in the near future to become similar to the Dow Lorsban labels. Be sure to carefully read the label when you buy new product to see if

Various generic chlorpyrifos products, e.g. Whirlwind, Warhawk, Govern, and Nufos. Each have their own requirements and restrictions including the number of applications that can be made. None of them allow post-bloom trunk sprays on apples. You will need to consult those labels and follow carefully.

Last year some growers wondered if they could legally apply one Lorsban or generic chlorpyrifos formulation pre-bloom and then follow later with another formulation for borer control. This is not legal! Whatever product you use for your first spray becomes the label you must stick with for the rest of the season. If you apply a Lorsban or generic chlorpyrifos formulation that allows only 1 spray per season, you cannot legally follow it up with a foliar spray of another product or with a trunk spray of Gowan's Lorsban 75WG (which allows a second spray for apple trunks on its label).
Lorsban and the chlorpyrifos generic products can also be used on other tree fruits. Check each label carefully for specific use restrictions for peach, nectarine, pear, plum, prune, and cherry.

Thionex (endosulfan)
Thionex 50W and Thionex 3EC are now restricted use products with longer Restricted Entry Intervals (REI). The REI for Thionex 50W for apples, apricots, nectarines, peaches, cherries, pears, plums and prunes is now 4 days. The REI for Thionex 50W is 9 days for blueberries and 5 days for strawberries. The REI for Thionex 3EC for apples, apricots, nectarines, peaches, cherries, pears, plums and prunes is now 2 days. The REI for Thionex 3EC is 6 days for blueberries and 2 days for strawberries. Other changes include the requirement for a closed cab for airblast sprayer applications. For apples only, there is an exception to the closed cab rule if not feasible; however, particular safety gear is required. In addition, do not apply within 100 feet of rivers, natural ponds, lakes, streams, reservoirs, marshes, estuaries and commercial fish ponds. Seasonal maximum rates were also reduced. Be sure to read these new labels before using.


Nova 40W is now called Rally 40W.

New Pesticide Labels

This year a number of new products, mostly insecticides, have been introduced. Some have already been added to the new 2009 New England Tree Fruit Management Guide. Others are new since the guide was printed.

Insecticides & Miticides:

  • Altacor 35 WG (chlorantraniliprole, rynaxypyr), DuPont, belongs to a new class of insecticides called anthranilic diamides. It is registered on pome fruits, stone fruits and grapes for control of a range of pests including leafrollers, codling moth, oriental fruit
  • Beleaf 50 SG, (flonicamid), FMC, is labeled for aphids and plant bugs on pome fruit and stone fruit. Researchers have reported good efficacy against green peach aphid and tarnished plant bug in peaches. The label also lists apple aphid, black cherry aphid,
  • Belt SC (flubendiamide), Bayer, belongs to the same new class of insecticides as Altacor. Belt is registered on pome fruits, stone fruits and grapes for control of a wide range of pests including leafrollers, codling moth, oriental fruit moth and grape
  • Centaur WDG (buprofezin), Nichino America, is an Insect Growth Regulator (IGR) labeled for use on apples, pears, and stone fruits for control of scale insects, mealybugs, leafhoppers and pear psylla. It is effective against the nymph stages by inhibiting chitin biosynthesis. It also suppresses oviposition of adults and reduces viability of eggs. Centaur is restricted to one application per year
  • Delegate (spinetoram), Dow AgroSciences, is a new spinosyn insecticide related to spinosad (Spintor, Entrust), but which has been chemically modified to be more active and effective against a broader range of insects. It is labeled for pome fruits, stone fruits, bushberries (blueberries, currants, gooseberry, etc.), caneberries (blackberry, raspberry, etc.) and grapes. It has efficacy against internal feeding Lepidoptera such as codling moth and oriental fruit moth, plus leafrollers and leafminers. It is also labeled for control of pear psylla, thrips and cherry fruit fly, and shows suppression of apple maggot and
  • Leverage (imidacloprid + cyfluthrin), Bayer, is a restricted use pesticide and is labeled for pome fruits, stone fruits and grapes against a wide range of pests. It is a combined formulation of imidacloprid (the a.i. found in Provado) and cyfluthrin (the a.i. found in Baythroid). The pome fruit label includes internal worms and leafrollers, aphids (except woolly apple aphid), apple maggot (when combined with a sticker), European apple sawfly, plum curculio, San Jose scale crawlers and plant bugs. The stone fruit label adds pests such as Japanese beetles, American plum borer and cherry fruit fly, among others. Do not apply pre-bloom or during bloom or when bees are actively foraging. It
  • Movento (spirotetramat), Bayer, is a new systemic foliar insecticide labeled for use on pome fruits, stone fruits and grapes. The pests controlled include aphids, mealybugs, pear psylla, San Jose scale, white peach scale and whiteflies. The product is active via ingestion against immature life stages and has shown effects on adult females by reducing survival of offspring. Do not apply until after petal
  • Onager (hexythiazox), Gowan, has the same active ingredient as Savey miticide and is used for control of mites such as European red mites and twospotted spider mites. They are both produced by Gowan Company but Onager is a 1EC liquid formulation and Savey is a 50 DF, water dispersible granule formulation. Onager is labeled for pome fruits, stone fruits and grapes. Savey is labeled for pome fruits,
  • Rimon 0.83EC (novaluron), Chemtura, is registered for use on apples. It is an insect growth regulator that interferes with the insect's ability to form chitin, thus disrupting the molting process. It is effective against the immature stages of insects and will not kill adults. The route of entry is primarily through ingestion, with some contact activity. The pests controlled include codling moth, leafminers, leafrollers, and oriental fruit moth, with suppression of white apple
  • Tourismo (flubendiamide and buprofezin), Nichino America, is labeled for use on pome fruits, stone fruits and grapes. It is a combined formulation of flubendiamide (the a.i. found in Belt) and buprofezin (the a.i. found in Centaur). The long list of pests on the label includes most of those on the Belt and Centaur labels. Do not apply prior to petal fall of pome and stone fruits.
  • Voliam Flexi (thiamethoxan + chlorantraniliprole), Syngenta, is labeled for use on pome fruits, stone fruits and grapes. It is a combined formulation of thiamethoxan (the a.i. found in Actara) and chlorantraniliprole (the a.i. found in Altacor). The long list of pests on the label includes most of those found on the Actara and Altacor labels. It is highly toxic to bees exposed to direct treatment or residues on blooming crops. After a Voliam Flexi application, wait at least 5


  • Adament 50 WG (tebuconazole + trifloxystrobin), Bayer, is labeled for use on peach, nectarine, cherry and grapes (except for Concord grapes). It is a combined formulation of tebuconazole (the a.i. found in Elite) and trifloxystrobin (the a.i. found in Gem). It is for management of a number of stone fruit diseases,
  • Inspire Super MP (difenoconazole), Syngenta, is labeled for use on pome fruits for apple scab, sooty blotch, flyspeck, cedar apple rust and other diseases. It is packaged along with cyprodinil (the a.i. in Vangard), which must be tank mixed and used together. Inspire Super MP is a sterol inhibitor (SI) fungicide in the same class as Rally, Rubigan and Procure; however, it is thought to be more effective on apple scab than these older SI products. Inspire has a 72 day Pre Harvest Interval
  • Quash 50 WDG (metconazole), Valent, is a sterol inhibiting fungicide labeled for use on stone fruits; primarily for brown rot and peach scab. Do not make more than 3 applications per season.
  • Quintec (quinoxyfen), Dow AgroSciences, is a fungicide labeled for cherries and grapes for control of powdery mildew.
  • Soil Fumigant:
  • Midas (iodomethane + chloropicrin), Arysta LifeScience, is a restricted use pesticide and pre-plant fumigant of fields intended for commercial production of a number of crops including stone fruits, strawberries and grapes. It is a broad-spectrum product used for control of soil-borne pests including weed seeds, nematodes, insects and diseases. There are a number of different formulations and fruit crops are not on all labels so be sure to check. Midas 33:67 and Midas 25:75 both include stone fruits, grapes and strawberries on the label. The label includes very specific information on how to apply this product.

Note: Information on new products was derived from a number of sources including other state Extension newsletters, pesticide manufacturer materials and pesticide labels.