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Healthy Fruit 2009 Vol. 17:2

Apr 14, 2009

Current (April 13) degree day (DD) Accumulations

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

  • Base 43: 116
  • Base 50: 40

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

  • pear psylla 1st oviposition: 40–126
  • spotted tentiform leafminer 1st catch: 110–198
  • McIntosh apple at green tip: 96–148
  • McIntosh apple at half-inch green: 155-201

Current bud stages

Location
McIntosh
apple --
green tip+
Bartlett
pear --
swollen bud+
PF-14 Jersey
peach --
swollen bud+
Cavalier
sweet cherry -- swollen bud

Belchertown
UMass CSO
(04/13/09)

McIntosh Green Tip Bartlett Pear Swollen Bud Jersey Peach Swollen Bud Cavalier Sweet Cherry Swollen Bud

The way I see it

We are into a nice dry weather pattern which should allow many orchard activities to take place. I have officially declared April 13 green tip on apples in Belchertown. If you have trees to plant, this looks like a good dry stretch to get them into the ground. Apple scab fungicides should be applied before wet weather hits again (early next week). It may also be a good time to apply oil as long as night-time temperatures do not drop below freezing. Peach pruning should be started in earnest. Ground fertilizer can be applied if caught up on all the above.

I hope you can attend one of next week's tree fruit twilight meetings. Also, note the food safety/GAPs training on May 6 -- I know it is a busy time, but if you missed the previous training session, it's very worthwhile and a timely topic.

J. Clements

 

New pest control products

Here are some of the new pest control products in 2009:

  • Altacor 35 WG (chlorantraniliprole, DuPont) is a new class of insecticide registered for control of leafrollers, codling moth, and oriental fruit moth on pome and stone fruit. It also works on apple maggot and is safe on most beneficials. Good coverage of foliage is essential to provide optimum control, which can last up to 14 days.
  • Belt 4 SC (flubendiamide, Bayer), like Altacor, is one of a brand new class of insecticides with target pests that include leafrollers, codling moth, oriental fruit moth, and leafminers in pome and stone fruits. It is relatively safe on beneficials.
  • Beleaf 50 SG (flonicamid, FMC) is is a new class of insecticide registered on pome and stone fruits for control of aphids and plant bug (suppression).
  • Clutch 50 WDG (clothianodin, Valent) is a neonic insecticide for use on apples and pears against aphids, leafhoppers, leafminers, psylla, plum curculio, apple maggot, oriental fruit moth, and codling moth. Obviously, it has a broad range of activity effective on piercing/sucking insects as well as several internal feeders. It has long residual activity.
  • Delegate (spinetoram, Dow) is a new compound in the spinosyn (SpinTor) class of insecticides. It is registered for use on pome and stone fruit to control leafrollers, codling moth, oriental fruit moth, and green fruitworm. Delegate provides up to 14 days control with good coverage, is safe on beneficials, however, toxic to bees exposed to direct treatment.
  • Leverage 2.7 SE (imidacloprid plus cyfluthrin, Bayer) is a pre-mix of two active ingredients registered for use on pome and stone fruits. It controls a broad range of pests, including leafrollers, codling moth, oriental fruit moth, green fruitworm, aphids, plant bugs, apple maggot, and plum curculio. Different rates are indicated for different pests.
  • Movento 2F (spirotetramat, Bayer) controls aphids, scale, and pear psylla. It has a unique two-way action where it is translocated to both roots (wooly apple aphid) and growing shoot tips. It is safe on beneficials and is registered on pome and stone fruits.
  • Quash (metconazole, Valent) is an SI fungicide for use on stone fruit. The primary disease target is brown rot and it is also labeled for powdery mildew.

J. Clements

Good Agricultural Practices (GAPs) Food Safety Training

Wednesday May 6, 2009 1:00-5:30 PM, UMass South Deerfield Research Farm

Foodborne outbreaks linked to fresh produce have increased in recent years. To address this issue, UMass Extension, the UMass Department of Nutrition and the MA Department of Agricultural Resources have teamed up to implement a USDA Good Agricultural Practices (GAP) Training Program for growers and other fresh produce handlers. This event will be held Wednesday, May 6 from 1-5:30 PM at the UMass South Deerfield Research Farm, River Road, South Deerfield. Attendees will learn about bacteria associated with fresh produce, strategies for controlling food safety hazards in all phases of production and USDA Third-Party GAP Audits. Participants will receive a GAP manual, a certificate of participation, and one pesticide credit is offered. Presenters include: Rich Bonanno, Ph.D., UMass Extension Educator 978-361-5650, rbonanno@umext.umass.edu; David Nyachuba, Ph.D., Assistant Professor, UMass Department of Nutrition 413-545-0552 dgn@nutrition.umass.edu; Scott Soares, Commissioner, MA Department of Agricultural Resources and Mike Botelho, MA Department of Agricultural Resources.

Preregistration is required. Registration deadline: April 27, 2009 To register send $50.00 payable to the University of Massachusetts to: Shirley A. Mietlicki-Floyd, UMass Department of Public Health, 205 Arnold House, 715 North Pleasant Street, Amherst MA 01003-9304

Healthy Fruit Disease Elements

Indar 75 WSP didn't make it into the 2009 New England Tree Fruit Management Guide, however, Inspire Super MP did. Indar is a classic SI fungicide, hence it has kickback similar to Rally (formerly Nova) or Rubigan and should be used similarly. As our apple trees have never seen it, it should be a good substitute for Rally/Rubigan, but if strong SI resistance is suspected, avoid it.

Post-infection up to tight cluster: The AP fungicides, Vangard and Scala, have up to 72 hrs. of post-infection activity, and are probably the best options at this time for a post-infection fungicide. They work best in cool weather, and don't do well against fruit scab. They are most effective through tight cluster.

New: Inspire Super MP is combination of Vangard and difenconazole, the latter a new chemistry and very strong SI. It should be a good option for eradication, but not a particularly good protectant. Note the MP stands for 'Multi-Pack.' The two chemicals must be applied together per the label requirement. So, one should probably mix the combo with mancozeb or captan to provide better protection activity.

Strobilurine fungicides, Flint and Sovran, are not particularly good post-infection fungicides. They're good protectants, and they can reduce spore production. But using these fungicides to reduce spore production will only hurry the development of resistance to them.

D. Cooley

Guest article

A REVIEW OF APPLE SCAB FUNGICIDES FOR 2009 (Dave Rosenberger, Plant Pathology, Highland)

reprinted from Scaffolds Fruit Journal, Vol. 18, No. 2, March 30, 2009

Note: I have excerpted from Dave's article a bullet list of "some other key points concerning options for early season fungicides for apples." Please see the complete article in Scaffolds Fruit Journal for "the rest of the story." J. Clements

  • Copper applied at silver tip to green tip will control scab just as well as a mancozeb spray. There
    is no need to mix another scab fungicide with copper.
  • Given the increased cost for mancozeb fungicides this season, Vangard and Scala may be cost- effective choices for sprays at green tip and/or half-inch green. These products do not redistribute, so they are best used in combinations with low rates (3 lb/A) of mancozeb or Captan 50W to ensure that any buds that are missed due to incomplete coverage will still be protected via redistribution of the contact fungicide. Vangard and Scala can provide up to 72 hr of post-infection activity, but post-infec- tion activity is dependent on complete spray cover- age. After half-inch green, Flint and Sovran may be better options than Vangard or Scala because redistribution capabilities become increasingly important as the pace of bud development speeds up.
  • The combination of a mancozeb fungicide at 3 lb/A plus Captan 50W at 1.5 to 3 lb/A is still an excel- lent choice for a protectant program. Neither of these products provides true post-infection activity, although they can be effective if applied within 12–18 hr of the start of rain periods. Where this combination is used continuously through petal fall or fi rst cover, it may be necessary to add 3 to 5 lb/A of sulfur to the mancozeb- captan mixture starting at the pink bud stage in order to control powdery mildew. Remember that neither captan nor sulfur is compatible with oil!
  • The stroby fungicides (Flint and Sovran) are "super protectants" (i.e., more effective than either captan or mancozeb). They are especially useful for enhancing scab control and mildew control programs from tight cluster through early cover sprays. For resistance management reasons, these fungicides should be tank- mixed with either captan or mancozeb and should not be applied more than twice in direct succession. Mancozeb is the preferred combination product where rust diseases are a problem. Remember that Sovran is toxic to some sweet cherry cultivars and Flint can damage some grape cultivars.
  • The SI fungicides are still very effective for controlling apple scab in some orchards, whereas scab has become resistant to them in other orchards. SI fungicides registered in NY include Rally (formerly Nova), Rubigan, and Procure. Indar and Inspire Super are registered in other states [INCLUDING MASSACHUSETTS] and will hopefully have their NY State registrations shortly. Indar and Inspire Su- per are more active against scab than the older SI fungicides and they will therefore provide more reliable scab control in orchards where the scab population is shifted toward SI resistance. Inspire Super is the most active and it may initially control scab fairly well in orchards that have experienced failures with Nova or Rubigan. However, no one can predict the reliability of Inspire Super if it is applied repeatedly in orchards where Nova and Rubigan have failed.