Caterpillars in Onions by Christy Hoepting

Several growers have spotted yellow hairy caterpillars feeding in their onions this season (Figure 1). These are saltmarsh caterpillars. After larvae hatch from their egg masses, they feed in groups on the underside of the leaf (Figure 2) before dis-persing to other leaves and to other plants. The feeding of small larvae does not go entirely through the leaf (Figure 3). Large larvae have been found making large holes in onion leaves and even feeding inside the onion leaves. We have noticed these caterpillars for about 3-4 weeks now. They should be dropping to the ground to pupate within a couple of weeks and we may see another gen-eration emerge later in the season. Their preferred hosts are weeds, especially pigweed, but they com-monly move into and feed on several different types of vegetables and field crops. It is common to see higher levels of these caterpillars along the edge of a field. Within a field, their activity is sporadic. In on-ions, they generally do not cause economic damage. Saltmarsh caterpillars should be very easy to con-trol with insecticides com-monly used in onions. Al-though not labeled specifi-cally for caterpillars in on-ions, pyrethroids (such as Warrior), Lannate and Radi-ant when used to control onion thrips, should also control these saltmarsh caterpillars.

Volume 7, Issue 16 July 13, 2011

Cooperative Extension Cornell Vegetable Program

Cornell University

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Contents Dates ........................................................................... 3

Sponsors ..................................................................... 9

Weather Charts .......................................................... 9

Crops Crops: Tidbits & Insights ................................... 4 & 5 Cabbage (Brassicas): Rate Alert for Synapse ........... 8 Cabbage & Cole Crops: Worm Control .................... 3 Onions: Caterpillars in Onions ................................. 1 Peppers: Aphids in Peppers .................................... 4 Sweet Corn: Trap Network Report, 7/12/11 ........... 7 Tomatoes: Septoria Leaf Spot on Tomato .............. 2 Tomato/Potato: LB Virulence Against Varieties ...... 6 Tomato/Potato: LB Severity Accumulations ........... 7 Vine Crops: Downy Mildew Control ........................ 8

Continued on page 2

Figure 1. Large saltmarsh caterpillar larvae

Figure 2. Hatched saltwater caterpillar larvae feeding in groups on the underside of an onion leaf. Photo: Amy Ivy

July 13, 2011 Volume 7, Issue 16 Veg Edge Weekly

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Continued from cover

Another caterpillar that could be found in onions is the leek moth, which is a pest of onion, leek and related Allium species. Larvae are small, yellowish-green with a pale brown head capsule and eight small grey spots on each abdominal segment and reach ½ inch in length (Figure 4). Leek moth was first detected in New York in 2009 in Plattsburg in four home gardens. It has also been confirmed to be in St. Lawrence and Clinton Counties and is suspected to have wider distribution. Reports suggest it is likely to spread in the US, especially in the Great Lakes Region. In Canada, leek moth has become problematic especially to small-scale, organic growers in eastern Ontario and to commercial producers in western Quebec, who have limited insecti-cides available to them. On onion leaves, leek moth larvae burrow into the leaves and leave “window pane” feeding damage, similar to diamondback moth in cab-bage (Figure 5). If you spot such damage, it would be worthwhile to split open the leaf to see if you can find the worm. Their lacy cocoons located on leaves are also fairly diagnostic (Figure 6). Once leek moth establishes itself, it will become a regu-lar pest that will have to be managed. In New York, there are 2ee registrations for several insecticides to manage leek moth in onion, garlic and leek, including Radiant SC, Warrior II with Zeon Technology, Lannate LV, Dipel DF Dry Flowable Biological Insecticide (although not effective when the larvae are feeding inside the leaves) and Entrust (OMRI approved). Fortunately, most of these materials also control onion thrips. More information on leek moth including damage on leeks and garlic, and for organic control, can be found at http://www.omafra.gov.on.ca/english/crops/facts/08-009.htm. If you suspect leek moth, contact Christy Hoepting.

Figure 3. Early feeding damage of saltmarsh caterpillars on an onion leaf. Photo: Amy Ivy

Figure 4. Leek moth larvae feeding inside an onion leaf.

Figure 5. Leek moth “window pane” feeding damage on an onion leaf. Photo: OMAF

Figure 6. Lacy cocoon of leek moth on leek. Photo: OMAF

Septoria Leaf Spot on Tomato J. Reid, CVP: This is a bad one. Why? Once it gets started it spreads quickly in the canopy and defoliates tomato plants, leaving fruit exposed to sun-scald and reducing yields dramatically.

How to prevent it? Field rotation is the most important aspect of control. Next, stake and trellis plants to re-duce the amount of soil splashing, which is how it is often spread. Straw mulch between the rows. Lower plant density for increased air movement. Control weeds such as Horse nettle which can be hosts. Work in affected parts of the field last. Finally, consider a fungicide program which is well described in Cornell Vegetable Guidelines

Greenhouse growers rarely see this disease, however once a facility is infected treatment is a challenge as the spores become dispersed in condensation or leaks. This week the disease turned up when scouting a veg farm in the Finger Lakes that also grew 3000 sq ft of greenhouse tomatoes. One part of the action plan there is for all workers to begin their day in the greenhouse before going to the field.

July 13, 2011 Volume 7, Issue 16 Veg Edge Weekly

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Dates... July 25 - PowerPoint and Your Farm, 7-9pm, Cornell Food & Agricultural Technology Park, Geneva. Learn how to use PowerPoint software to plan and create a basic digital slideshow. Will also cover how to make posters or signs for your farm or farm stand using this software. $10. To REGISTER: Call Nancy Anderson at 585-394-3977 x427 or send name, address and phone number to nea8@cornell.edu

August 2 - Annual Elba Muck Onion Twilight Meeting Mark your calendars!

August 4 - Innovations in Organic Research Thompson Vegetable Research Farm, 133 Fall Creek Rd, Freeville, 4 – 7 pm. Join NOFA-NY and Cornell University for a look at: organic variety trials in vegetables bred for late blight, downy mildew and cucumber beetle resistance; soil health impact of cover crops; organic potato management; and reduced tillage cover crop-ping for broccoli.

August 9 - Protecting & Improving Your Crops From the Soil Up 4-7pm, Mud Creek Farm, McMahon Rd, Vic-tor. Crystal Stewart, CDVSFP, will focus on best management techniques for organic farmers trying to eliminate or prevent garlic bloat nema-tode and soil-borne pests and pathogens. Learn the management techniques that promote soil physical health, reduce soil compaction and encourage healthy soil microbia. To register, visit NOFA-NY Shopping page or by call (585)271-1979 ext 512.

August 9-11 - Empire Farm Days, Rodman Lott & Sons Farm, Seneca Falls. For more info: 877-697-7837 or mwick-ham@empirefarmdays.com

August 12-14 - NOFA Summer Conference UMass Amherst. 225 workshops on organic farming, gardening, land care, draft animals, homesteading, sustainability, nutrition, food politics and more. Go to: http://www.nofasummerconference.org/beginningfarmer.php

Cabbage & Cole Crops: Worm Control

Relative efficacy of products for worm control in cole crops

Material, Sm Lg Formulation & Rate ICW CL CL DBM3

Ryanodine receptor modulator (Group 28) Synapse WG (3-5 fl oz) xxx xxx xxx xx Spinosyns (Group 5) Radiant SC (5-10 fl oz) xxx xxx xxx xx Diamides (Group 28) Coragen (3.5 – 5 fl oz) xxx xxx xxx xxx Voliam Xpress9 (5-9 fl oz) xxx xxx xxx xxx Indoxacarb (Group 22) Avaunt 30WG6 (0.15 – 0.22 lb) xxx xxx xxx xxx Avermectin (Group 6) Proclaim 5G (2.4 – 4.8 oz) xxx xxx xx2 xxx Pyrethroids (Group 3A) Warrior T 1CS (1.92 – 3.2 fl oz) xxx xxx xx x Endigo ZC (4 – 4.5 fl oz)8 xxx xxx xx x Danitol 2.4 EC (10.6 – 16 fl oz) xxx xxx xx x Brigade/Capture 2EC (2.1 – 6.4 fl oz) xxx xx xx x2

Pounce/Ambush (0.05 – 0.2 lb ai) xxx xx x x Baythroid 2 (1.6 – 2.4 fl oz) xxx xx x2 x Ammo 2.5EC (2.5 – 5 fl oz) xxx xx2 x2 - Mustang 1.5EW (2.9 - 4.26 fl oz) xxx xx2 x2 - Asana XL 0.66EC (5.8 – 9.6 fl oz) xxx x2 x2 - Hero (4-10.3 oz) ? 7 ? ? ? Bts (Group 11) Bt kurstaki (see labels) xxx xx2 x2 x2

(Biobit, Javelin, DiPel, Condor, Crymax) Bt aizawai (see labels) xxx x x xx4

(Xentari, Agree, Ketch) OPs (Group 1B) Orthene/Address 75S/97 (1.3 lb) xxx xx xx x Carbamates (Group 1A) Lannate LV 2.4L (1.5 – 3 pt) xxx x2 x2 x2

Larvin 3.2F (16 – 40 fl oz) xxx x2 x2 x2

Sevin 80 Solupak (1.25-2.5 fl oz) x - - x Chlorinated Hydrocarbon Thionex 3EC (1-1.33 qts) x x - x

C. Hoepting, CVP: Not surprisingly, the heat has brought about all the worm pests including diamondback moth (DBM), imported cabbage worm (ICW) and even cabbage loopers (CL). Following is a list of insecticides labeled for use on various cole crops with tentative efficacy ratings for control of ICW, small and large CL and DBM put together by Cornell researchers in Long Island. Growers and other researchers may have somewhat different opinions and results vary according to rates, application method and frequency, location, etc. so selection of controls should not be made solely based on this chart. Not all materials are labeled for all crops or areas - check labels. For most cole crops, addition of a spreader-sticker is advised.

xxx = most effective (usually good control expected); x = least effective (fair or poor control); - not labeled or not effective. Not all formulations listed. Rates in amount of formulated product unless otherwise indicated. 1 4.5 – 6 oz for CL; 2 higher rates needed; 3 Where insecticide resistance is not a problem better control of DBM with some materials may be expected; 4 Bt aizawai may provide better control of DBM where populations are resistant to Bt kurstaki; 5 some incidental control; 6 Avaunt is not labeled for use on Long Island. 7Has not been trialed in University studies. 8a premix of Warrior + Actara/Cruiser. 9A premix of Coragen + Warrior.

July 13, 2011 Volume 7, Issue 16 Veg Edge Weekly

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CROPS Tidbits & Insights Aphids in Peppers

J. Reid, CVP: Of the several insects that damage peppers, aphids cause symptoms most often confused with disease. Leaves become dis-torted and twisted, stunted (see photo). Only a few aphids feeding on the growing point of a pepper can cause the damage, which lasts the life of the plant. Thus scouting for aphids is very important.

This week aphids were found in damaging numbers on local peppers, but we also found high numbers of beneficial insects such as lady-

beetles (see photo) in the same field. We recom-mend the application of selective materials that preserve populations of non-pest insects such as lady beetles. In 2010 we achieved good aphid con-trol with commercial for-mulations of Beauvaria bassiana, a fungus that infects aphids. Botanigard and Mycotrol (OMRI) (see

chart) are good examples. More

aphicides are described in Cornell Vegetable Guidelines

Stunting and twisting of pepper leaves due to aphids.

Lady beetle, a beneficial insect, in peppers.

CARROTS Processing carrots are suffering from late planting coupled with hot dry weather. There are some fields at the 3-5 leaf stage that are being sprayed for aster leaf-hoppers. Leaf diseases are minimal so far. Carrots in most fields have not grown significantly the past week due to lack of water. Some fields have been irrigated.

Lorox applications are tricky this year. In general, you should wait until most of the carrots have emerged. You can use multiple applications of low rates (0.25 lb/acre) if the weeds haven’t gotten too large. Although the label states that higher rates can control broadleaf weeds up to 6 inches tall, Robin Bellinder (Cornell) says you shouldn’t let ragweed get taller than 4 inches. It’s a balance between killing the weeds and injury to the crop. For larger weeds in young carrot fields use a rate somewhere between 0.25 and 0.5 lb/acre. The 0.5 lb rate is likely too harsh on young carrots. If the weeds aren’t growing either because it’s too dry, then wait until we get some rain (or irrigation) to spray. Best results are obtained on succulent weeds growing under conditions of high humidity and temperatures of 70°F or higher. Do not spray when the temperature is greater than 85°F.

DRY BEANS Later planted dry beans are emerging unevenly due to very dry soils. In earlier fields emergence and early growth was good but plants are small due to the dry weather. Flowering will occur this week. Post-emergence herbicide spraying has occurred and some growers have cultivated.

Potato leafhopper (PLH) adults and nymphs are build-ing up in organic fields and where seed was not treated with Cruiser. PLH levels were approaching the threshold of 5 PLH adult/1 sweep with a net or 1 nymph per trifoliate leaf. Beans are especially suscep-tible to yield decreases from PLH if they are infested prior to bloom. Many insecticides are effective and labeled for PLH control on beans, including pyrethroids (Baythroid, etc), chloronicotinyls (Assail, etc), combi-nations (Leverage), Voliam Xpress, Dimethoate (not when crop is in bloom). Pyganic is effective for organic growers but multiple applications are needed for con-trol. See the Cornell Vegetable Guidelines at http://www.nysaes.cals.cornell.edu/recommends/ or the Organic Guides at http://www.nysipm.cornell.edu/organic_guide/default.asp Where seed was treated with Cruiser you should still have control if you don’t see any nymphs on the undersides of leaves. A few winged aphids and red headed flea beetles (FB) could also be seen in untreated fields. The FB eat small holes in the leaves but don’t usually do significant damage.

USDA NASS June Acreage Report: US dry edible bean planted area is forecast at 1.26 million acres for 2011, down 34% from 2010. For a table of dry bean area planted in 2011 by state, compared to 2010, go to the link and scroll down to pg. 23: http://www.usda.gov/nass/PUBS/TODAYRPT/acrg0611.pdf

More tidbits on page 5...

July 13, 2011 Volume 7, Issue 16 Veg Edge Weekly

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CROPS Tidbits & Insights (continued)

GARLIC A recent tour of garlic producers plus an influx of garlic samples being sent into the lab at Geneva is showing that garlic bloat nematode is still active and in numbers that are causing significant damage for seed stock production. As harvest begins for garlic look for light weight bulbs, separated cloves, whimpy plants, and basal rot. These are some of the clues that the garlic may be infested. German White variety of garlic has been mostly affected but others have as well. Destroy all suspected garlic if you are saving bulbs for seed.

ONIONS Onions are looking better than expected given the 3-week dry spell. Early varieties of transplanted onions are lodging. In general Botrytis leaf blight (BLB) is down in direct seeded onions; unless levels are below 1 BLB lesion per leaf, BLB fungicides need to be continued. BLB is virtually undetectable in transplanted onions, but the first Purple Blotch (PB) lesions were detected this week. Transplanted onions should have a PB fungicide such as Scala, Rovral or Quadris in the tank mix. Bravo and mancozeb are weak on PB.

Onion thrips (OT) increased this past week in the heat, and several transplanted fields have reached the spray threshold of 3 OT per leaf for Movento. In general, direct seeded fields are still below threshold. This is an important time to scout for OT to determine when to make the first spray, because spraying when OT pressure is below 1 OT per leaf is not economical and waiting too long until they are greater than 3 OT per leaf can make them challenging to control. With harvest of wheat starting this week, it is expected that there will be a greater influx of OT into onion fields. A penetrating surfactant must be used with Movento to make sure that it gets into the plant where it acts systemically. To avoid reduced efficacy of Movento when tank mixed with Bravo weatherstik or other fungicides formulated with spreader-stickers, either use another fungicide that is not formulated with a spreader-sticker, and/or use the highest rate of penetrating surfactant to overcome this interaction. Small-scale growers who are not using Movento or Agri-Mek, but are relying on Radiant for OT control, it is a label requirement to not use more than two sequential applications of Radiant before switching to another mode of action for resistance management. Other options include Lannate (a carbamate) and pyrethroids such as Warrior. ote that pyrethroids have failed in several years of Cornell studies due to the development of resistance. If using a pyrethroid: i) apply at 1 OT per leaf or lower, and ii) if after 7 days, OT counts are higher (same is okay), than switch to another mode of action (Radiant is okay to use again). Radiant has a 3 OT per leaf threshold and a maximum of 30 fl oz per crop per season.

PEAS Harvest of the first batch of processing peas is nearly done and there will be about a ten day gap before the next group is ready. Yields of processing peas have been low, averaging 1.6 ton per acre so far.

POTATOES The potato crop is developing, with earlier fields setting tubers. There are some thin stands due to seed decay and very “aged” seed, which produces few, weak sprouts or small tubers instead of sprouts. Soils are very dry and some growers are irrigating.

Potato leafhoppers (PLH) are rapidly migrating into potato fields. Potatoes are very sensitive to the toxins that PLHs produce and some “hopperburn” can be seen. If you do not see PLH nymphs on the undersides of leaves then you know your insecticide seed or in-furrow treatment is still working. Mid-July is the time when at planting insecticides usually wear off but with the very late planting they should still be working for PLH. If they aren’t think back to the application of the insecticide. If you used a tube to deliver the material into the furrow it should be on target. If you used a spray nozzle because you were also applying a fungicide recall how wide the fan pattern was. Did it extend beyond the open furrow? If so, then some insecticide was lost on the soil surface. To correct this you can either move the nozzle down closer to the open furrow or twist the nozzle a little to make the fan spray pattern narrower. See the 6/29 Veg Edge Weekly for more on PLH.

Colorado potato beetle (CPB) summer adults are emerging and laying eggs. If you used chloronicotinyl insecticides on the seed or in-furrow (Admire, Cruiser, etc) or in foliar sprays (Assail, Provado, Leverage, Endigo ZC, etc) for first generation CPB larvae, then you should not use insecticides in this chemical class for summer adults or larvae, or other insects. Altacor and Voliam Xpress are effective against CPB adults, as well as larvae, and will control small European corn borer (ECB) larvae. Voliam Xpress will also control aphids and PLH. If small to me-dium CPB larvae are your target Radiant and Avaunt are other possibilities but they will not control aphids or PLH. OMRI approved materi-als for organic growers, for small to medium CPB larvae include Entrust or Mycotrol, or if you’re targeting egg hatch Novodor, Neemix or Pyganic. Pyganic will also control PLH but multiple applications are needed.

Reminder: Post emergence herbicides and sprays of 2,4-D for enhancing red color will cause more crop injury if temperatures are 85°+F. NY potato growers planted an estimated 16,500 acres this year up 2% from 2010. US area planted to fall potatoes in 2011 is estimated at 948,600 acres, up 6% from 2010. Cold, wet weather delayed planting in ME, ND and OR (as well as in NY). Subscribe to NY reports at www.nass.usda.gov/ny

SNAP BEANS There are snap beans in nearly all stages of growth out in the field now. Planting of processing beans has been on schedule since the first of June. Herbicide damage has been observed in some fields due to weather issues. There are a lot of potato leafhoppers in the area. Beans with Cruiser seed treatment should be protected through bloom. For untreated beans, there are several insecticides labeled (see Cornell Guidelines). Pyganic is effective for organic beans, but multiple applications are needed. For more information on potato leafhoppers, see the June 29 issue of Veg Edge Weekly.

SWEET CORN There are only a few fields of processing corn that are in the tassel stage. ECB larvae are already being found in the tassels. Lack of water has been a factor in slow growth in some fresh market sweet corn stands but generally, it is starting to come on with harvests taking off.

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Late Blight Virulence Against Tomato & Potato Varieties*

C. MacNeil, CVP (info from T. Zitter and W. Fry, Cornell):

Characteristics of Late Blight Isolates

US-24 has occurred primarily in the Midwest; Mefenoxam is the active ingredient in fungicides such as Ridomil. On late blight isolates that are sensitive to mefenoxam. It provides truly systemic activity and excellent control.

US-22 has been most prevalent the past couple of years though US-8 has also been present in NYS. Previously, US-8 was the predominant late blight isolate (since the 1990's). US-11 and US-17 were locally problems, mostly on tomatoes, in 2002, 2006 and in spots in 2009.

The tables below refer to FOLIAR resistance only.

Tomatoes

Variety Late Blight Isolate

Fresh Market US-8 US-22 US-11 US-17

Legend OP Tol Tol

Defiant PhR Res Res Res

Mt. Merit Res Res?? Res

Heirlooms US-8 US-22 US-11 US-17

Aunt Ginny's Purple Res

Aunt Ruby's German Green Mod Res

Big Rainbow obs res

Black Krim mixed Mod Res

Black Plum Res

Brandywine Mod Res

Pruden's Purple Mod Res

Tigerella (AKA Mr. Stripey) Tol

Large Cherry, Plum US-8 US-22 US-11 US-17

Juliet F1 Mod Res

Mt. Magic F1 Res Res Res

Plum Regal F1 Res Res Res

Small Grape, Cherry, Pear US-8 US-22 US-11 US-17

Red Currant OP Res

Red Pearl, grape Mod Res

Matt's Wild Cherry obs res Res

Yellow Currant Tol

Yellow Pear OP HE Tol

Potatoes

Late Blight Isolate*

Variety US-8

Allegany Mod Susc

Castile Mod Susc

Dorita Mod Susc

Elba Mod Res

Green Mountain Mod Susc

Katahdin Mod Susc

Kennebec Mod Res

Rosa Mod Susc

Russet Burbank Mod Susc

Sebago Mod Res

Serran Mod Res

Snowden Mod Susc

Tol = some tolerance; Res = resistant (not immune); Mod Res = moderate resistance; obs res = some observations of resistance; mixed = mixed reaction, sometimes res and sometimes not. If no rating is indicated it means the variety is susceptible or that it hasn't been exposed to the isolate.

Mod Susc = moderate susceptibility; Mod Res = moderate resistance

* US-8 has been much more of a problem on potatoes in NYS than the other isolates. Out of 46 standard and specialty varieties tested these are the only ones that are not completely susceptible.

Note: The complete list of tomato varieties with their horticultural characteristics and seed sources can be found at the CVP website at http://blogs.cce.cornell.edu/cvp/ in the Crops, Tomatoes menu on the left.

Potato varieties are described in the NY Certified Seed Directory for 2010 at http://www.cals.cornell.edu/cals/plpath/about/facilities/upload/2010NYPOTATOCropDirectory.pdf

July 13, 2011 Volume 7, Issue 16 Veg Edge Weekly

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*Accumulations start 5/05/11 **Airport stations, with RH increased to estimate field conditions

Late Blight Severity Value Accumulations

C. MacNeil, CVP: Late blight (LB) severity value (SV) accumulations for the past week are very low to high at the weather stations across the 12 counties of the CVP. The upcoming cooling trend and very cool nights that are forecast are likely to produce heavy dew, however. The new LB Decision Support System (DSS) takes into account NWS forecasts 5 days into the future and it is predicting that a fungicide spray will be needed by 7/15 at many locations if the last application was 7/6 even where the old Blitecast system currently shows 0 SVs for the past week. The LB DSS is located at: http://blight.eas.cornell.edu/blight/ To get a password contact Ian or Laura at ims56@cornell.edu or lje5@cornell.edu.

So far this season LB has been reported on potatoes and/or tomatoes in central PA, ME, CT, FL, VA, DE, WI, and on Long Island, NY. LB has not yet been confirmed in upstate New York but we’ve heard of sus-picious symptoms in gardens 2+ weeks ago after the very rainy weather. The symptomatic leaves were picked off and discarded, and then it turned dry, so there’s currently no evidence. I will be checking up later this week after the hot weather breaks and we’ve had some night time dew. I have informed all the Ag Staff and Master Gardener Coordinators in the CVP counties and neighbors that all possible cases of LB need to be taken seriously and that the CVP staff should be informed so growers can be alerted if necessary.

This year it is critically important that any confirmed LB of potatoes or tomatoes, whether from a commercial farm or a garden, be shipped to Dr. Bill Fry, Plant Pathology, Cornell, so that the LB isolate can be determined. There have been several different isolates in the past

few years (US-8; US-22; US-23, etc). Depending on which one is present it may be more or less virulent on tomatoes vs pota-toes. In addition, until the isolate is known we cannot make the best recommendation regarding fungicide choice. If an isolate is sensitive to mefenoxam (active ingredient in Ridomil, etc) apply-ing it will be much more effective than any of the other fungi-cides we have. US-22, US-24 and possibly US-23 are sensitive. US-8 is resistant.

If you think you may have LB contact a member of the CVP Team. LB can be confirmed in our Canandaigua office (contact Carol MacNeil - 585-313-8796 or crm6@cornell.edu or John Gibbons - 716-474-5238, or jpg10@cornell.edu), by the Monroe CCE Diag-nostic Lab, or by the Cornell Diagnostic Lab in Ithaca. Seal sam-ples to be checked in a plastic bag, keep at room temperature out of the sun until delivery, preferably within a day. LB can only survive on fresh, live, green, turgid leaves and stems. Here is a link to photos to help you determine whether you may have LB http://www.longislandhort.cornell.edu/vegpath/photos/index.htm Scroll down to Potatoes and/or Tomatoes and click on Late Blight.

Confirmed samples should be overnight mailed to the Bill Fry Lab, Plant Pathology, Cornell, Ithaca. Chris Smart, tomato LB researcher, Plant Pathology, Geneva, may be able to facilitate this transfer to Ithaca. Clearly label the sample as LATE BLIGHT so it’s handled promptly. Don’t mail if samples will arrive over the weekend. There is no charge for determining the LB iso-late. Results should be available in a couple of days.

To get a report from Abby Seaman’s, NYS IPM Program, Late Blight Network on her LB Blog on new LB confirmations go to http://blogs.cornell.edu/lateblight/2011/ You can subscribe to receive the reports at the bottom right of the web page by typing in your email address and clicking on Create Subscription.

For a factsheet on LB: http://nysipm.cornell.edu/factsheets/vegetables/potato/late_blight_fs.pdf

If you have questions contact Carol MacNeil at 585-313-8796 or crm6@cornell.edu.

Location Week Total* Location Week Total*

Albion 0 43 Geneva 1 58

Appleton 1 48 Lafayette 9 80

Baldwinsville 0 ** Lodi 3 36

Buffalo** 0 34 Portland 3 49

Ceres 6 48 Ransomville 2 42

Elba 2 42 Sodus 2 36

Farmington 0 37 Williamson 1 39

Fayette 0 38 Wellsville** 1 48

Late Blight Severity Value Accumulation 7/12/11*

WNY Sweet Corn Trap Network Report, 7/12/11

Abby Seaman, NYS IPM Program

Both ECB E and Z race moths are generally low this week, with the exception of Hamlin, where the E race counts increased. Fields with emerging tassels are still infested with ECB from the earlier flight, but in many cases, if larvae in the emerging tassels are controlled with tassel emergence applications, fields in areas with low trap catches may not need additional applications before harvest. In Hamlin, where higher numbers of adults are being caught, new ECB egg masses are being found. Most locations did not report corn earworm catches, and those that did reported 1-3 moths for the week. Fall armyworm and western bean cutworm were each caught at only one location this week.

ECB ECB

Location -E -Z CEW FAW WBC

Baldwinsville (Onondaga) 2 0 3 0 0

Batavia (Genesee) 0 1 1 0 0

Bellona (Ontario) 0 3 0 0 1

Eden (Erie) 0 0 0 0 0

Farmington (Ontario) 0 4 0 0 0

Great Valley (Cattaraugus) 1 3 0 0 0

Hamlin (Monroe) 22 4 0 0 0

LeRoy (Genesee) 4 7 0 0 NA

Lockport (Niagara) 0 0 0 0 0

Penn Yan (Yates) 0 7 0 0 0

Spencerport (Monroe) 0 0 0 0 0

Waterport (Orleans) 0 1 0 0 0

Williamson (Wayne) 1 2 1 0 0

WNY Pheromone Trap Catches: July 12, 2011

July 13, 2011 Volume 7, Issue 16 Veg Edge Weekly

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R. Hadad, CVP: Downy mildew has now been confirmed in Michigan and Ohio. Yesterday and unconfirmed sample was found in Erie Co. NY. Getting the cu-cumbers, melons, and squash protected is necessary at this point. The hot dry weather will last only so long. Morning dews are enough to allow the disease to become established on leaves.

Broad-spectrum contact protectant fungicides (Bravo, Maneb, Dithane, cop-per) provide some downy mildew control. Researchers in NC regularly con-ducting fungicide efficacy trials for downy mildew rated chlorothalonil (4 rat-ing) better than mancozeb and maneb (3) and also copper (1).

Mobile (systemic, translaminar) fungicides with an active ingredient that spe-cifically targets oomycete fungi are recommended beginning when downy mildew is forecast to occur in the area or symptoms have just started to de-velop. Apply every 5-7 days depending on disease severity. Fungicide resis-tance is a concern with this pathogen and with these fungicides due to their specific mode of action; therefore, alternate among systemic fungicides in different chemical classes and tank-mix with protectant fungicides when the systemic is not formulated with a protectant. Fortunately several systemic fungicides are now available. Their efficacy was similar when compared in recent fungicide efficacy experiments.

Curzate (cymoxanil, FRAC Group 27 fungicide) is labeled for use at 3.2 oz/A on a 10-14 day schedule for a maximum of 9 applications. It has a 12 hr REI and 3 day PHI. Since this product reportedly has good curative activity (about 3 day kickback), it is a good product to use first after downy mildew is detected. However, it has poor residual activity (only 1-2 days), thus it is critical to tank-mix it with a protectant fungicide and to follow-up with another systemic fun-gicide when disease pressure is high. Curzate should be used as soon as possi-ble after rain if not applied before (2 hr rainfastness). Tanos is another fungi-cide with cymoxanil.

Forum (dimethomorph, Group 15), a new formulation replacing Acrobat, is labeled for use at 6 oz/A tank-mixed with protectant fungicide on a 5-10 day schedule for a maximum of 5 times with no more than 2 sequential applica-tions. PHI is 0 days. REI is 12 hours. Tank-mix with protectant fungicide.

Gavel (mancozeb and zoxamide, Group 22) can be used on cucumber, melon, summer squash, and watermelon but not currently on pumpkin and winter squash because it contains mancozeb. Gavel is labeled for use at 1.5–2.0 lb/A, every 7 to 10 days or when conditions are favorable for disease for a maxi-mum of 8 applications.

Revus is group 40 and a new product. Other new products are phosphorus acid fungicides (Phostrol, ProPhyt, and Fosphite)(cyazofamid; Group 33) are more effective than Aliette. They have a 12 hr REI and can be applied to all cucurbits at 2.5-5 pt/A, on a 7-14 day interval up to 6-7 times/crop. Phosphite ion, the active ingredient for these fungicides, effects fungal pathogens di-rectly and promotes the plant’s defense system.

Previcur Flex (propamocarb, Group 28) is labeled for use at 1.2 pts/A on a 7-14 day schedule for a maximum of 6 pts. PHI is 2 days. REI is 12 hours. Recommended tank-mixed with protectant fungicide.

Ranman (cyazofamid; Group 21) is labeled for use at 2.1-2.75 fl oz/A on a 7-10 day schedule for a maximum of 6 applications (16.5 fl oz) with no more than 3 consecutive applications followed by at least 3 applications of fungi-cide in another FRAC group. It has a 12 hr REI and 0 day PHI. Recommended tank-mixed with protectant fungicide.

Tanos (cymoxanil, Group 27, plus famoxadone, Group 11) is labeled for use at 8 oz/A, tank-mixed with protectant fungicide, on a 5-7 day schedule for a maximum of 4 ap-plications of Group 11 fungicides including Tanos. It has a 12 hr REI and 3 day PHI. Curzate is another fungicide with cymoxanil. Forum, Ranman, Gavel, Tanos and phosphorus acid fungi-cides are also labeled for Phytophthora blight, which is caused by a pathogen related to the downy mildew fun-gus.

Fungicides with mefenoxam (Ridomil Gold Bravo, Ridomil Gold Copper, Group 4) are highly effective but more at-risk for resistance than fungicides mentioned above. Ri-domil Gold Bravo is applied at 2 lb/A. REI is 48 hours.

QoI (aka strobilurin) fungicides (Group 11) are no longer recommended for downy mildew because resistant strains of the pathogen have been detected in the US. Although impact of resistance on efficacy is not known, there are several other effective, mobile fungicides. Tanos is one Group 11 fungicide that is still recommended be-cause it contains an additional active ingredient, cymox-anil. Other Group 11 fungicides include Amistar, Cabrio, Flint, and Pristine. When compared for managing patho-gen strains without resistance to this group, Cabrio has been more effective than Amistar. Reason (fenamidone) has a federal label and could soon be registered in NY.

The key is thorough application of the materials on both sides of the leaf. High volume of water to get good cover-age and keep on schedule as the vines grow bigger.

Rate Alert for Synapse on Cabbage (Brassicas)

Dan DiGiacomandrea, Bayer CropScience

Our Brassica label rate has recently changed (3/23/11) from 2 fl oz/acre to 3-5 fl oz/acre. Unfortunately the CDMS label found on-line is the old (11/21/08) 2 oz/acre label. Confusing the issue is a Supplemental label in CDMS that lists the new rate range.

results should be acceptable at that rate. However, we should be recom-mending a minimum of 3 oz now.

Our Regulatory folks have been noti-fied of the confusion and should be updating CDMS etc.

We have done work with both the 2 and 3 oz rate on Brassica worms over the years and have had good efficacy with both rates. Apparently the rate was upgraded to reflect our rate ranges on other labeled veggies. So, there are commercial applications tak-ing place at 2 oz, and we expect that

Vine Crops: Downy Mildew Control

Volume 7, Issue 16 Veg Edge Weekly

Page 9

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Weather Charts

*Airport stations ** Data from other station/airport sites is at: http://newa.cornell.edu/ Weather Data, Daily Summary and Degree Days.

July 13, 2011

J. Gibbons, CVP:

Rainfall (inch) Temp (°F)

Location Week Month Max Min

Albion 0.00 0.00 90 59

Appleton, North 0.00 0.00 87 55

Baldwinsville 0.00 0.00 91 59

Buffalo* 0.00 0.00 87 59

Ceres 0.49 0.49 86 49

Elba 0.09 0.09 88 54

Farmington 0.00 0.02 91 55

Geneva 0.00 0.00 90 60

Himrod **** **** 91 59

Lafayette 0.00 0.00 90 55

Lodi **** **** 88 59

Lyndonville 0.00 0.00 89 57

Ransomville 0.00 0.00 87 57

Rochester* 0.05 0.05 92 60

Syracuse* 1.54 1.54 93 60

Williamson 0.05 0.00 93 60

Weekly Weather Summary: 7/05 - 7/11

Location 2011 2010 2009

Albion 1060 1211 874

Appleton, North 813 1022 708

Buffalo 1106 1214 912

Elba 994 1204 726

Farmington 1073 1187 836

Geneva 1188 1414 927

Himrod 1139 1222 883

Lafayette 1127 1138 863

Lodi 1212 1344 ***

Lyndonville 1035 1215 861

Ransomville 1041 1203 846

Rochester 1139 1273 863

Syracuse 1346 1296 969

Williamson 1070 1250 836

Accumulated Growing Degree Days (AGDD) Base 50°F: Jan. 1 — July 11, 2011

Cooperative Extension Cornell Vegetable Program

Cornell University Serving Allegany, Cattaraugus,

Erie, Genesee, Monroe, Niagara,

Onondaga, Ontario, Orleans,

Seneca, Wayne and Yates Counties

Veg Edge Weekly is a seasonal weekly publication of the Cornell Vegetable Program providing information about crop development, pest activity and management, pesticide updates, local weather conditions, meetings and resources.

Veg Edge is published 28 times annually, monthly from October-May and weekly from May-September. If you have any questions about this publication, contact Julie Kikkert at 585-394-3977 x404 or jrk2@cornell.edu. Visit the Cornell Vegetable Program website at http://cvp.cce.cornell.edu/ for information on our research, upcoming events and enrolling in our program.

Cornell Cooperative Extension provides equal program and employment opportunities.

Robert Hadad 585-739-4065 Cell rgh26@cornell.edu

Christy Hoepting 585-721-6953 Cell cah59@cornell.edu

Julie Kikkert 585-313-8160 Cell jrk2@cornell.edu

Carol MacNeil 585-313-8796 Cell crm6@cornell.edu

Judson Reid 585-313-8912 Cell jer11@cornell.edu

Cornell Vegetable Program Extension Specialists

John Gibbons, 716-474-5238 Cell

Katie Klotzbach 585-732-2545 Cell

CVP Assistants

This publication contains pesticide recommendations. Changes in pesticide regulations occur constantly and human errors are possible. Some materials may no longer be available and some uses may no longer be legal. All pesticides distributed, sold or applied in New York State must be registered with the New York State Department of Environ-mental Conservation (DEC). Questions concerning the legality and/or registration status for pesticide usage in New York State should be directed to the appropriate Cornell

Cooperative Extension specialist or your regional DEC office.

Cornell Cooperative Extension and its employees assume no liability for the effectiveness or results of any chemicals for pesticide usage. No endorsement of products or com-panies is made or implied. READ THE LABEL BEFORE APPLYING ANY PESTICIDE.

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