Volume 11, Issue 18                                                                                                    July 25, 2003


Vegetable Insects - Joanne Whalen, Extension  IPM Specialist;   jwhalen@udel.edu



We continue to find low levels of aphids in seedling stage cucumbers. A treatment should be applied for aphids if 10 to 20 percent of the plants are infested with aphids. Actara, Fulfill, Thiodan or Lannate will provide aphid control. A penetrating surfactant (e.g. LI-700 or AD-100) should be used with Fulfill.


Lima Beans.

Heavy leafhopper populations can also be found  on seedling stage lima beans. If nymphs are easily detected and you can find plant damage a treatment may be needed. As soon as pin pods are present, scout fields for lygus bugs and stinkbugs. Treatment should be considered if you find 15 adults and/or nymphs per 50 sweeps. Lannate, Capture or Warrior can be used if both species are present. A higher rate of Capture (4 oz/A), Mustang (4.3 oz/A) or Warrior (3.84 oz) will be needed if stinkbugs are the predominant insect present. Although our overwintering corn earworm population has been low to moderate, reports from Virginia indicate that pheromone trap catches are higher than normal. So, this could mean that we will see a heavy migratory population. As soon as pin pods are present, you should also begin sampling fields for corn earworm.



Continue to scout all melons for aphids, cucumber beetles, and spider mites. Spider mite population levels continue to increase and multiple sprays may be needed.  A treatment will be needed for spider mites if you find 20-30% of the plants infested with 1-2 mites per leaf. If populations of mites have exploded and adult mites are the predominant life stage, Capture or Danitol should be used. If the population is a mixture of eggs, immature mites and lower levels of adult mites, Agri-Mek should be used at 8 oz/acre. A second miticide application may be needed in 3-7 days depending on the population level at treatment time. We are also starting to find a few melon aphids. The treatment threshold for aphids is 20% of the plants infested with at least 5 aphids per leaf. Fulfill, Lannate and Thiodan are labeled on melons and will provide melon aphid control. A penetrating surfactant (e.g. LI-700 or AD-100) should be used with Fulfill. Be sure to watch for bees foraging in the area and avoid insecticide applications on blooming crops. Be sure to follow all label restrictions regarding insecticide applications during bloom.



At the present time, all peppers that have fruit ˝ inch in size or larger should be sprayed on a 7-day schedule for corn borer and pepper maggot control. A spray will also be needed for CEW as soon as trap catches begin to increase. Remember Orthene or Address will not provide satisfactory earworm control. A pyrethroid or Lannate will be needed for earworm control. A continuous pyrethroid program should not be used to avoid aphid explosions.


Snap Beans.

Seedling beans should still be watched carefully for leafhopper activity. The leafhopper threshold is 5 per sweep. Since corn borer catches are starting to increase, corn borer sprays should be applied at the bud and pin stages on processing snap beans. After the pin spray, sprays will be needed on a 5-day schedule until harvest. Since this can change quickly, be sure to check our website for the most recent trap catches and information on how to use this information to make a treatment decisions in processing snap beans  (http://www.udel.edu/IPM/traps/latestblt.html and our link to http://www.udel.edu/IPM/thresh/snapbeanecbthresh.html).  As soon as pin pods are present, fresh market beans should be sprayed on a 7-day schedule. Lannate, Capture,  Mustang or Warrior should be used.


Sweet Corn.

Fresh market silking sweet corn should be sprayed on a 3-4 day schedule throughout the state.   Be sure to check the IPM website for the most recent BLT catches in your area (http://www.udel.edu/IPM/traps/latestblt.html). We continue to find low levels of fall armyworm larvae in the latest planted corn. No controls will be needed until 15% of the plants are infested. Since fall armyworm feed deep in the whorls, sprays should be directed into the whorls and multiple applications are often needed to achieve control.




Vegetable Crop Diseases Bob Mulrooney Extension Plant Pathologist; bobmul@udel.edu


Be on the lookout for anthracnose on watermelons. Several samples have been diagnosed with anthracnose this week. The wet weather and favorable temperatures have been conducive for infection. Look for angular spots that can be limited by the veins on the leaves, but not always. Tan elliptical lesions can be found on the stems of wilting plants. Fruit symptoms are numerous, shallow depressions on the fruit with salmon colored spore masses on the lesions. See accompanying photos. Fungicide applications of 3 ptsA of Bravo plus 0.5 lb./A of Topsin are recommended on a 7-day schedule. Good coverage is very important especially to protect the fruit from infection.



Anthracnose lesions on watermelon leaf




Anthracnose lesions on watermelon stem.





Pickle and Lima Bean Situation Reports

Ed Kee, Extension Vegetable Specialist; kee@udel.edu

Pickling Cucumbers – Situation Report

The USDA reports that U.S. processors have contracted 32% more than a year ago, with all states posting an increase, with the exception of Wisconsin.  Cucumber contract tonnage is at an all time high in 2003, totaling 53,600 tons.  In the chart below, Delaware and Maryland are included in “other states.”  Estimated acreage in our two states is approximately 7,500 to 8,000 acres.


Cucumbers for Pickles

Contracted Acreage



2003 Contract

2002 Contract

% Change









North Carolina








South Carolina












Other States1




Total U.S.





12002 includes AL, CA, DE, FL, GA, MD, MA, MO, and WA

     2003 includes AL, CA, DE, FL, GA, MD, MA, AND MO



Fordhook Lima Beans – Situation Report

The national pack of Fordhook lima beans is expected to be lower this year, due to poor germination of California plantings and the closure of a California plant.  Over 90% of Fordhook production is in California.  As a result of the lower pack, prices for frozen product are expected to increase.  Current prices of 12/16 oz. cases of fordhook limas are around $13.75 per case.


The development of the ‘Sussex’ variety of Fordhook lima beans has shown promise for use in Delaware.  Research plots and several limited commercial trials have indicated it has the potential to yield competitively and produce high quality beans under Delaware conditions.  This year, two processors have nearly 375 acres planted, and if successful, they plan for more acreage in the future.




Field Crops


Field Crop Insects - Joanne Whalen, Extension  IPM Specialist;   jwhalen@udel.edu



Heavy potato leafhopper populations can still be found in many fields. Remember, once yellowing occurs damage has already been done and additional damage will affect the longevity of the stand. The treatment thresholds are 20 per 100 sweeps on alfalfa 3 inches or less in height, 50 per 100 sweeps in 4-6 inch tall alfalfa and 100 per 100 sweeps in 7-11 inch tall alfalfa.


Field Corn.

Continue to watch for Japanese beetles and corn rootworm adult beetles feeding on silking corn. The decision to treat should be based on the number of beetles per silk as well as how far you are in the pollination period. A treatment is recommended on silking corn if you can find 4-5 rootworm beetles per plant or 3 or more Japanese beetles per plant and they are clipping silks to less than ˝ inch long before 50% pollination. Once brown silk is present, silk clipping will not affect ear fill.



Heavy potato leafhopper populations and "hopper burn" can be found in seedling stage soybeans throughout the state. As a general guideline, a spray may be needed if you find 4 per sweep in stressed beans and 8 per sweep in non-stressed fields. There are no thresholds for numbers per leaf however, if leafhoppers are easily detected and you can see symptoms of plant damage, a treatment may be needed.  A pyrethroid or dimethoate will provide control.


Continue to watch fields carefully for soybean aphids. We have detected low levels of soybean aphids in New Castle County and Sussex Counties. If economic populations develop, timing of the insecticide application will be very critical. As a general guideline, treatment at flowering would be recommended if aphids are abundant on most plants, Current guidelines from the Midwest say treat if you find 25 or more aphids per leaflet. The following products are registered and have provided effective control:  Asana, Furadan, Lorsban, Mustang MAX , Penncap-M, Pounce and Warrior.


Continue to scout for grasshoppers and spider mites in seedling stage beans. Grasshopper populations remain high, especially in soybeans planted after barley and wheat. Grasshoppers can be controlled with Asana, Baythroid,  Dimethoate, Furadan, Lorsban or Warrior. We continue to find low levels of spider mites in an occasional field. Dimethoate, Lorsban or Parathion are the available products.




Grant Opportunities For Delaware Growers


Sustainable Agriculture Grants for Northeast Farmers


Farmers in the Northeast who are interested in conducting innovative production and marketing projects are encouraged to apply to the Sustainable Agriculture Research and Education (SARE) program for grant funds for projects starting in the spring.

Applications can address a broad range of agricultural issues such as pest management, soil and water conservation, aquaculture, marketing, grazing, bee health, no-till, pasture management, agroforestry, and other sustainable farming techniques. Northeast SARE defines sustainable agriculture as agriculture that is profitable, environmentally sound, and good for the community. In 2003, the average grant was about $5,200; grants are capped at $10,000.

Any full- or part-time farmer in the Northeast SARE region can apply. The region is made up of Connecticut, Delaware, Massachusetts, Maryland, Maine, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, West Virginia, and Washington, D.C. Applications and more information about the requirements of the Farmer/Grower Grant program are available on the Northeast SARE web site at www.uvm.edu/~nesare/. You can also call 802/656-0471 to request a printed application. The proposal deadline is December 8, 2003.


Delaware growers are encouraged to apply. 






Agronomic Crops Twilight Tailgate Session


When:    Wednesday, July 30, 2003

Where: UD Cooperative Extension Research and Demonstration Area (3/4-mile east of Armstrong Corner, on Marl Pit Rd. – Rd 429, Middletown)

Time:    6:00 PM

Bring:    A tailgate or a lawn chair


Join your fellow producers and the UD Extension team for a discussion of this year’s demonstration trials and current production issues in small grains, corn, and soybeans. We expect to have the 2002-2003 wheat and barley variety trial results for distribution and discussion. Brief updates will include nutrient management, risk management and grain marketing. We will wrap things up with the traditional ice cream treat!


We will apply for both DE Pesticide and Nutrient Management re-certification credit.


This meeting is free and everyone interested in attending is welcome. To register, for more information or special consideration in accessing this meeting, please call our office in advance, at (302) 831-2667.  


See you there!  Carl P. Davis, Extension Agent, Agriculture


Pesticide Container Recycling

Each container is closely inspected for cleanliness (they must be triple rinsed or equivalent), chipped and bagged for storage and transport. Container chips are combined with those collected in similar programs across the country and processed into pallets, park benches, new pesticide containers, or converted into fuel.

Containers are collected at the Sussex Conservation District, Maintenance Yard, Shortly Road, Georgetown, DE, and at the large commercial applicator sites. The Sussex Conservation District site is open 6 months out of the year and the dates and times for collections are:

  • August 21, 2003
  • September 18, 2003

Collection hours are from 9:30 a.m. – 1:30 p.m.





                 Weather Summary



Weeks of July 17 to July 24, 2003


0.01 inches: July 20

0.26 inches: July 22

0.07 inches: July 23

0.01 inches: July 24


Readings taken for the previous 24 hours at 8 a.m.

Air Temperature:

Highs Ranged from 90°F on July 21 to 80°F on July 23.

Lows Ranged from 76°F on July 22 to 62°F on July 18.

Soil Temperature:

78F average for the week.

(Soil temperature taken at a 2 inch depth, under sod)


Web Address for the U of D Research & Education Center:




Compiled and Edited By:

Tracy Wootten

Sussex County Extension Educator - Horticulture





Cooperative Extension Education in Agriculture and Home Economics, University of Delaware, Delaware State University and the United States Department of Agriculture cooperating, Robin Morgan, Director.  Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914.  It is the policy of the Delaware Cooperative Extension System that no person shall be subjected to discrimination on the grounds of race, sex, disability, age or national origin.

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