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SCAFFOLDS Fruit Journal, Geneva, NY                             Volume 5 
Update on Pest Management and Crop Development                 June 17, 1996

COMING EVENTS

43F 50F Current DD accumulations (Geneva 1/1-6/17): 962 591 (Highland 1/1-6/17): 1319 824 Coming Events: Ranges: San Jose scale 1st flight subsides 768-1058 434-648 Oriental fruit moth 1st flight subsides 781-1574 442-1026 Dogwoood borer 1st catch 798-1182 456-718 Obliquebanded leafroller 1st flight peak 869-1548 506-987 Pear psylla 2nd brood hatch 992-1200 609-763 TRAP CATCHES (Number/trap/day) Geneva: 5/30 6/3 6/6 6/10 6/13 6/17 Redbanded Leafroller 0 0.1 0.3 0 0 0 Spotted Tentiform Leafminer 13.5 63.4 29.2 15.4 5.3 3.8 Oriental Fruit Moth 0 1.5 1.8 0.8 0.5 0 Lesser Appleworm 1.5 5.3 0.8 0.5 0.7 0 Codling Moth 0 6.3 5.3 5.5 21.5 2.5 San Jose Scale 0 0 0.5* 0 0 0.1 American Plum Borer 0 11.6 1.7 1.8 1.8 3.0 Lesser Peachtree Borer (cherry) 0 0.1* 0.2 0 0.5 0.8 Lesser Peachtree Borer (peach) 0 0 0.2* 0.8 3.7 3.1 Peachtree Borer - - - 0 11.7* 8.3 Pandemis Leafroller - - - 0 0 0.4* Obliquebanded Leafroller - - - 0 0 0.8* Highland (Dick Straub, Peter Jentsch) 5/13 5/20 5/28 6/3 6/10 6/17 Redbanded Leafroller 0.9 1.0 0.6 0.6 0 0 Spotted Tentiform Leafminer 6.4 4.7 5.1 0.3 1.8 55.1 Oriental Fruit Moth 4.5 1.0 0.9 1.2 1.4 0 Lesser Appleworm 0 0.1* 0.2 0.2 0.1 0.9 Codling Moth 0 0.1* 2.8 4.1 6.8 5.2 Fruittree Leafroller 0 0 0 0 0 0 Tufted Apple Budworm 0 0 0.4 0.8 0.6 0.8 Obliquebanded Leafroller - - - 0 0.1* 4.9 Sparganothis Fruitworm - - - 0 0.1* 0.5 * = 1st catch Pest Focus Highland - 17-year Cicadas damaging limbs Rose Leafhopper migration to apple nearly complete RLH and White Apple Leafhopper oviposition beginning Fresh Plum Curculio scars still being found Geneva - 1st catch of Obliquebanded Leafroller (Station plantings), 6/17



DISEASE UPDATE

By: Dave Rosenberger, Plant Pathology, Highland

Fabraea on Pears

Pear growers should maintain fungicide coverage in their pear blocks throughout June and early July to protect trees from fabraea leaf spot. Fabraea leaf spot can destroy a pear crop more quickly than any other fungal disease I have seen. Fabraea epidemics are usually reported in early July when the disease suddenly "explodes" in certain blocks. Fungicide protection during late June is necessary to prevent the early infections that provide inoculum for the July epidemics.

Fabraea overwinters either in small (<1/4 inch), indistinct cankers on pear twigs or in fallen leaves on the orchard floor. Fabraea first appears as small round purplish leaf spots. Very few growers or fieldmen recognize the early fabraea infections because they are rather nondescript leaf spots and there are very few of them at first. Each of these initial infections, however, can produce millions of slimy spores that are disseminated by splashing rain or by pear psylla and other insects. If spores are disseminated by insects, infection can occur during long dew periods in the absence of rain. Economic damage is usually caused by the rapid development of secondary infections in orchards where primary infections became established in June. If fungicide protection is lacking or inadequate, fruit can become severely infected during July and August. Severely infected Bosc trees can lose most of their leaves by late August. Bosc are more susceptible than Bartlett, but the disease can affect most pear cultivars.

Fabraea is relatively easy to control if fungicides are applied before the disease reaches epidemic proportions in an orchard. Mancozeb is the most effective fungicide for fabraea, but it cannot be used within 77 days of harvest. Ziram is probably the best bet for controlling spread of fabraea during summer. Benlate has been effective in some trials and ineffective in others. Ziram applied on a 3-week interval will provide adequate protection except where heavy rains remove fungicide residues, or where the disease was well established before the first spray was applied. Where disease pressure is very high (i.e., early infections were not controlled), sprays may need to be applied on a 14-day interval.




LAST CALLS AND HEADS UP

By: Art Agnello, Entomology, Geneva

With the arrival at last of some genuine summer weather, we approach the closing of a few treatment windows for certain pests and the opening of others. First of all, as of today, 6/17, a total of 484 DD have accumulated in the Hudson Valley since the "1st adult catch" biofix; in Geneva, the value is 318. The recommended spray window to control 1st generation codling moth is 250-360 DD, so 1st brood larvae are no longer in the susceptible treatment window in the Hudson Valley. For those growers with severe CM pressure in blocks where apple maggot sprays are not generally applied during the summer, we will maintain DD readings and once again begin posting them when the next control window approaches (1260 DD from the biofix date).

For plum curculio, the situation is much the same in advanced and inland sites. Recalling that curc movement into orchards for oviposition should be about over by 340 DD (base 50 F) after petal fall, the accumulated value (for McIntosh) in Geneva is at 318. For other sites: Albion, 357; Lyndonville, 340; Williamson, 339; Sodus, 321; Appleton, 315. We're perilously close to the endpoint in many of these spots, so (particularly in view of the heavy rains that have fallen in some spots) it would probably be prudent to be sure your blocks are protected through the middle to end of this week, and then we'll be done with this character for the season.

Agri-Mek probably has little more than this week to go for consideration as a treatment option (mainly in western N.Y.), whether for European red mites in apples or pear psylla in pears. We got a bit of a break on leaf condition this season because of the abundant moisture, so most foliage has not yet hardened off appreciably. However, delaying either of these applications past this week would probably be pushing your luck on the absorption potential of this material.

Obliquebanded Leafroller

Technically speaking, moths have been flying since last week, but their appearance has been uncharacteristically spotty and diffuse. Our first catch was in Higland and Wolcott on 6/10, followed by Albion on 6/12 and Geneva on 6/13 (6/17 in the Station plantings); all of these were single-moth catches. However, pupae were in evidence on Friday, even along the lake, so without having the benefit of current trap reports from most sites I'm still assuming that most areas will see widespread catches starting today. First hatch is generally assumed to occur about 360 DD (base 43 F) after flight starts, and for Highland our value stands at 215 as of today; in Wolcott we've only reached 153.

Section 18 Confirmed. On Friday, 6/14, we heard from the EPA and the N.Y. DEC that New York's Section 18 application for the use of tebufenozide (Confirm) to control OBLR in apples finally has been approved. Rohm and Haas informs us that product should be moving to the distributors beginning today, so with a little hustling on the part of everyone concerned, growers should be able to make an application as early as is required -- probably 6/19 or 6/20 at the earliest. Following are the specific conditions and restrictions of this exemption:

A maximum of 4 applications, at a rate of 18 fl. oz. of Confirm 2F in a minimum of 100 gpa per application (0.28 a.i.) may be applied by ground application.

A preharvest interval of 14 days is required.

A restricted entry interval of 4 hours must be observed to comply with WPS.

The EPA encourages stakeholders to work on resistance management strategies to reduce the likelihood of OBLR developing resistance to tebufenozide.

Spotted Tentiform Leafminer

You will note from the pheromone trap counts that the 1st brood spotted tentiform leafminer flight bottomed out in Geneva last week, and the 2nd brood should be starting any day. The 2nd flight has just begun in Highland.

By the second or third week of July, this flight should have peaked and eggs will have hatched, at which time we recommend sampling leaves for the young (sap-feeding) mines of the second generation, to determine the need for a spray. Sampling should be conducted when the first of the mines reach the tissue-feeding stage. This is the time when most of the population is in the sap-feeding stage, and it usually occurs about 500-700 degree-days (base 43 F) after the start of the second moth flight. The larvae can be found easily at this stage, but they have not yet caused much damage to the leaf. You may wish to make a note of the 2nd flight's start date in your region, or use the Geneva date for accumulating degree-days in your locality if you don't happen to document this event in local traps.

European Corn Borer

After further plumbing some of the mysteries of this insect's N.Y. distribution with Chuck Eckenrode at Geneva, I think I'm straight on which race shows up in which place. Apparently, the univoltine "Z" race (peak flight in mid-July), can be found almost continuously from Buffalo to Albany. The bivoltine "Z" race (peak flights in mid-June and mid-August) is present from Buffalo to about Rochester, and the bivoltine "E" race (also with peak flights in mid-June and mid-August) picks up from Rochester to Syracuse or thereabouts. In the Hudson Valley, all 3 races are probably present.

Fortunately, this means that most apple growers can promptly forget all of this detail and concentrate on its import, which is that most places have flights in the middle of June, July AND August. Susceptible orchards (young nonbearing, and others in the midst of sweet corn populations) must therefore be protected almost continuously during the summer, using something relatively long-lasting. This generally means either Penncap-M, Lorsban, Lannate, or Asana. Sorry it's not easier, but this is rapidly becoming a major player in some apple systems, and for the time being we have few alternatives.


1996 FRUIT FIELD DAY AT THE GENEVA EXPERIMENT STATION

On Tuesday August 13, 1996, Cornell University will sponsor a Fruit Field Day at the New York State Agricultural Experiment Station in Geneva, NY, to update growers on the latest research and extension advances in fruit crops. The field day will begin at 8:30 a.m. and end at 4:30 p.m. and is open to all interested fruit growers, consultants and industry personnel. The field day will cover tree fruits, grapes and small fruits. The morning presentations will be for all participants and will highlight fruit breeding and enology, production systems, integrated pest management, genetic engineering, physiology, water and nutrient management. The afternoon presentations will be commodity-oriented, with separate tours for grapes, stone fruits, small fruits and apples.

The schedule for the day is:

8:00 - 8:30 am Registration

8:30 -12:00 noon Field presentations on: fruit breeding and enology, production systems, integrated pest management, genetic engineering, physiology, and water and nutrient management

12:00 - 1:30 pm Lunch with State and Federal legislators (Co-sponsored by NYS Horticultural Society)

1:30 - 3:00 pm Grape Tour 1 Small Fruit tour Apple tour 1

3:00 - 4:30 pm Grape Tour 2 Stone Fruits tour Apple tour 2

The afternoon tours will run concurrently and growers will choose 2 tours based on their interests. Details of the specific stops are currently being arranged and will be announced soon. A registration of $10.00 will be charged, which will include lunch. Advance registration is requested. Please mail in the attached reservation form by August 3 or phone in your reservation to Art Agnello (315) 787-2341 by August 10.

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Enclosed is $___________for __________ persons ________________________

(Number) (Name)

(Address)

_______________________________

_______________________________

_______________________________

Please make checks payable to: Cornell University - NYSAES

Mail to:
Art Agnello
Dept. of Entomology
New York State Agricultural Experiment Station
Geneva, NY 14456



Scaffolds is published weekly from March to September by Cornell University -- NYS Agricultural Experiment Station (Geneva), and Ithaca -- with the assistance of Cornell Cooperative Extension. New York field reports welcomed. Send submissions by 3 p.m. Monday to:

Scaffolds Fruit Journal
Editors: A. Agnello, D. Kain
Department of Entomology, NYSAES
Geneva, NY 14456-0462
Phone: 315-787-2341 FAX:315-787-2326
E-mail: art_agnello@cornell.edu


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