• Corn pests

• New corn insecticide coming

• Cucurbit pest update

• Mistake in the vegetable guide

• Late blight in surrounding states

• Phytophthora

Corn earworm
The number of CEW moths in pheromone traps remained at relatively low levels for this time of year all around the state.  Traps captured between 1.2 and 4 CEW moths/night in Shelton, Northford, Berlin, and at 2 farms in East Lyme leaving those locations on a 4-day spray schedule on fresh silking corn.  Traps in East Hartford and in Storrs at the Research Farm, captured just 1 moth/night putting those sites on a 5 day spray schedule.  In Falls Village they captured just 0.1 moth/night this week and are not spraying silking corn at this time.  There was also a second trap in Shelton that failed to capture any moths this week, but because the trap across town captured 2 moths/night, we left him on a 6 day schedule in that field.  These schedules can be safely stretched by 1 day if using Warrior.  Be sure to include a spreader sticker with your silk applications this week, as we seem to be in a pattern of daily afternoon showers.   

Here are the CEW thresholds: 

moths per night		recommended spray interval
0-0.2		No spray
0.2-0.5		6 day schedule
0.5-1		5 day schedule
1-13		4 day schedule
>13 moths		3 day schedule

Higher Fall armyworm infestations
Traps in Shelton and East Lyme captured 3 and 5 FAW moths this week, similar numbers to what they captured a week ago, while a second trap in Est Lyme, and traps in  Northford and East Hartford captured 0-1 moth again this week. 

FAW caterpillar infestations in pre-tassel stage corn reached 30% at one farm in East Lyme, while the other farm in the same town had no FAW in their pre-tassel or whorl stage corn.  Pre-tassel stage corn in East Hartford also required treatment this week as 12% of the plants were infested with FAW.  Infestations ranged from 14 to 16% in mid- to late whorl stage corn in East Lyme, East Hartford and in Shelton.  If you normally don=t scout for this insect in your pre-tassel stage corn, it may be a good idea to check this week, because high infestations seem to be common right now.  Remember this insect will migrate down to the ear as the tassel pops open, before there is silk on the plants, so a silk spray schedule will not keep the corn worm-free if you have over 10-15% of the plants infested at pre-tassel.  SpinTor, Avaunt, and Intrepid all work well on this pest.  Warrior works well most of the time.

European corn borer  
Trap counts for ECB went up slightly at most locations around the state this week.  Traps in Shelton, Berlin and Northford captured 7 to 28 moths and should be spraying peppers for borer this coming week.  A trap in East Lyme captured 6 moths, just under the threshold, but would probably be advised to make an application on peppers this week also.  So far, I have only found one corn borer larvae in whorl stage corn.  Definitely a light and late second generation. 

Here is a list of infestations found at different sites while scouting sweet corn this past week. *means that the planting is over threshold and should be sprayed. MW=mid-whorl, LW= late-whorl, PT=pre-tassel, S=silk. 

Town	% infested plants	Stage of planting	ECB  & FAW moths / week	CEW moths/N
Shelton	2% 4% 14%* FAW	PT LW MW	7 ECB, 5 FAW	2 = 4-day schedule 0 = 6-day*
Northford			28 ECB, 1 FAW	4 = 4-day schedule
East Lyme I	6% CEW 0%	PT LW	6 ECB, 1 FAW	2.2 = 4-day schedule
East Lyme II	30%* FAW 14% * FAW	PT LW	3 FAW	1.2 = 4-day schedule
Berlin	2% FAW	LW	7 ECB	1.2 = 4-day schedule
East Hartford	12%* FAW     16%* FAW	PT LW	3 ECB, 0 FAW	1 = 5-day schedule
Storrs				1 = 5-day schedule
Falls Village				0.1 = no spray

New corn insecticide coming
In the past, I have told you how they are having trouble with insecticide resistance for products such as Warrior and other synthetic pyrethroids out in the upper Mid-West. This week Bayer announced that they have a new national label for a product with some new chemistry.  The product is called Belt, which contains the active ingredient flubendiamide, which is in a new and separate chemical family.  It is registered to kill CEW, ECB, FAW, and even black cutworm on sweet corn and pop corn.  Belt controls these caterpillars by causing them to stop feeding when ingested.  It has a 12 hour reentry interval, a 1 day-to-harvest restriction and is applied at 2 to 3 ounces per acre, with a limit of 12 ounces per acre.  It is not yet registered in Connecticut but I=m sure it will be soon.  I haven=t yet seen any efficacy data on this product, but when I do I'll be sure and share it with you.    

Cucurbit pests
In fields that had applied systemic products, such as Pristine or Procure, there was very little spread of powdery mildew this week.  In some fields there was some spread on lower vines, but very little on the upper or lower leaf surfaces.  

Plectosporium is becoming much easier to find in pumpkin fields across the state as the wet weather continues.  If it stays this wet for much longer, Plecto may become hard to control. 

No sign of downy mildew (DM) this week anywhere in Connecticut, although newsletters from neighboring states say that it is in counties right over the border in New York.  The stain of DM in the Northeast this year seems to be damaging only cucumbers and cantaloupe.  Be sure to scout your cucurbit crops again this week to detect this disease before it can defoliate your crop. 

On pumpkins, growers should be coming up on their second or third powdery mildew/Plecto/black rot spray.  Growers that used Pristine in their first spray should use Procure or Nova in their second spray, and vice-versa.  Be sure to use a protectant, such as Bravo, with the Procure or Nova as these materials only control PM, and you will need a broad-spectrum fungicide for all the other important diseases with all this wet weather.  If you have already applied both groups of systemics this season, and are coming up on your third spray, then you should switch to sulfur and Bravo.  Remember that the sulfur brand Microthiol Disperse dissolves nicely in the spray tank and does not clog nozzles.

Mistake in the vegetable guide
Quintec is listed for powdery mildew in the pumpkin and squash section and in the cucumber and melon section.  In fact, it is not registered for use on any cucurbit crop in Connecticut or New England.  New York has a special local needs label to use this product on melons, but Connecticut does not. This product is registered for powdery mildew control on grapes, cherries and hopes in all states, but that doesn't help us much in vegetable production, despite the fact that it is by far the most effective product on this disease.

Late blight in surrounding states
Late blight, the disease that caused the Irish potato famine, has been found in Pennsylvania, Maine, Vermont and Massachusetts.  I checked with the Connecticut Ag Experiment Station diagnostic lab, and they have not seen any cases of late blight in Connecticut.  This disease will usually kill all the foliage in a potato or tomato planting in a week or two under wet conditions, unless the fields are protected by a fungicide.  Most of the same fungicides that we have listed before for downy mildew control on pumpkins also control late blight on tomatoes and potatoes, since both of these diseases are water molds like Phytophthora.  In fact, late blight is another species of Phytophthora.  Note that both Bravo and Cabrio are listed as moderately effective products for late blight control in the New England Management Guide and in other publications.  Other effective materials include Tanos, Ranman, and Curzate.  See the New England Vegetable Management Guide for a more complete list for each crop.  Late blight often first appears as large half-dollar sized, dark green or brown spots on the leaves.  It is suggested to mix additional late blight fungicides with your early blight fungicides only if there is a confirmed case of late blight within a mile of your farm or if your crop becomes infected.  Severely infected plantings should be plowed under or destroyed to prevent spread of this disease on the wind.  It is also important to bury cull piles and destroy volunteer plants to help prevent the spread of this disease.

Phytophthora
As you might imagine with all this rain, there are many farms in the state that are struggling to control Phytophthora Blight.  One farm on the IPM program had numerous summer squash plants collapse this week from this disease.  This disease starts in low wet holes after flooding and then spreads uphill from plant to plant after subsequent heavy rainfall events, as secondary spores actually swim to the roots of adjacent plants.  Phytophthora blight does not travel on the wind the way late blight does.  It is very important to observe proper sanitation to avoid contaminating the soil on your farm with long-term resting spores.  That means do not compost rotting fruits and vegetables that you have purchased off-farm on your fields.  Also, this disease can be brought in on machines or tires that have been in infected soils, fields or farms when the soil is wet.  It can also spread down stream/river from infected sites and be pumped onto clean fields through irrigation systems.  The only effective control for Phytophthora is water management, but even that can fail when we get 17 inches of water in two weeks as one grower reported.  You can read more about how to prevent the spread of this disease through water management on the IPM web site or in the IPM pepper manual.