8.  Vegetable Scouting Report for week of July 10-15-from Cornell University


Sweet Corn

Looking at many corn fields we are finding something that goes against what we usually find in the field.  European corn borer (ECB) adults normally fly between the end of May and the middle of June.  After the flight, because the adults find the most mature corn most attractive, larvae populations are usually highest in the most mature corn.  The percentage of ECB worms in later plantings decreases until the second flight begins in late July.  This summer, we are finding more ECB worms in the second and third plantings than the first plantings.  I think this is because of all the rain we had in May and June. We had an up and down flight where normally the flight peaks and then numbers go down after that.  This is a guess but in any case, we are seeing higher percentages of ECB in later corn plantings as we go along.

It is quick and easy to find out how much ECB you have in your fields.  Walk through the field and stop randomly at 5 locations.  Inspect 5 plants at each location for ECB feeding damage - holes, saw dust and windows in the leaves around the tassel.  Scouting is quick because you are only looking for the presence or absence of feeding damage.  If you see damage on a plant, keep a running count of that number.  When you've inspected 25 plants, multiply the number of plants with holes times four and this gives you a percentage of field infestation.  If you are over 15% than a control is called for.  

Scout your fields for tassel emergence.  With the warmer weather, the tassels are opening quickly and since the ECB larvae do not like the heat, they do not stick around very long.  After tassel, the larvae either drop down to the ear or they bore into the stem making them more difficult to eliminate.  When you see around 30-40% of the field with the tassel just starting to stick out, make your first application.  Since the field will be coming quickly, the time before your second application will be shorter, maybe 2-3 days.  Keep an eye on your fields that are about to come into tassel as sprays at tassel are the most effective at controlling the worms.  For organic growers, Entrust, the organic formulation of Spintor, works very well. 


As stated earlier, late blight has been found on Long Island.  It seems to rain about every other day.  When you have 18 plus hours of over 90% RH than conditions are perfect for late blight.  Now that we have late blight close to our region, it is very important to have protective fungicide sprays already on the plants. Late blight produces large black spots on the leaves.  Sometimes, on the stems, you will see black areas at a stem where a spore germinated.  If you find something you think is late blight, call  your local Cooperative Extension office and have someone come out to positively ID the disease or call me at 518-434-0016.

Leaf hopper is being found in very high numbers in most fields.  Go out and flop a plant into the row and shake it, than flop the plant to the other side of the row. Inspect the ground for leaf hoppers that have fallen off the plant onto the ground.  This is an easy way to see what is happening in the field.  We've already started to see some burning on susceptible varieties.  The edges of the leaves will turn dark brown.  Eventually the whole plant will turn brown and die.  It's important to pay attention to leaf hopper because they can seriously decrease yield without being very evident. For conventional growers, Phaser and Thionex are the insecticides least toxic to ladybird beetles  This is important for aphid suppression.  For organic growers, the options are limited.  Pyganic is the only product that is organic certified that will do the job. 

The only other thing being found in potato fields is bacterial black leg.  This is when water gets into a damaged stem and causes the stem to turn black and rot usually producing a strong smell.  You often see this problem worst in spray rows where the plants are damaged by tractor wheels.  Later in the season, if the heavy rains continue, you will see black leg as a result of European corn borer damage. 

Vine crops
We found the first powdery mildew (PM) on summer squash this week.  It will always be the first vine crop to develop this disease so it is a good idea to try to isolate it from your other vine crops especially cucumbers.  Otherwise the PM will jump from one crop and planting to another. Be on the lookout for Phytophthora crown rot because of all the rain.  Plants will wilt and the stems will decay at the soil line.  Phytophthora is a common problem in many grower's fields.  We usually see it later in the season when the fruit collapses.  This early, with all the rain, we can see the problem on young plants.  Not much to do but hope we get drier conditions. 

Cornell Recommends
The online version of the 2006 Integrated Crop and Pest Management Guidelines for Vegetables is now available at


9.  Take a look at this issue of New Ag Network-a newsletter for and by Upper Midwest organic farmers and educators

In this issue –July 12, 2006

[log in to unmask]">What’s causing my vegetables to wilt?


[log in to unmask]">Organic matter amendments and the development of disease suppressive soils


[log in to unmask]">Economics of organic field crops


[log in to unmask]">United States and regional supply of certified organic field crops and livestock


[log in to unmask]">Asian soybean rust update for organic producers


[log in to unmask]">Field day planned in Michigan: Enhancing pollination and biological control with native plants


10.  Soil Building and Organic Market Workshop


On August 23, 2006 Michigan State University and Morgan Compost Inc. will sponsor a workshop on soil building of organic and biological systems. We will also offer a time to visit buyers of organic produce and grains and discuss organic market opportunities.  The day will feature a speaker from MidWest Biosystems, Roger Kropf, presenting Building Soil Fertility with integration of compost, cover crop and soil amendments.”  The day will end with a tour of compost production and incorporation of soil amendments including cover crops and compost.

  For information on the agenda, registration and directions please visit the web site or call Vicki


Vicki Morrone

Organic Vegetable and Crop Outreach Specialist

Michigan State University

C.S. Mott Sustainable Food Systems

303 Natural Resources Bldg.

East Lansing, MI 48824


517-282-3557 (cell)

517-353-3834 (fax)



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