Volume 9, Issue 22                                                                       August 24, 2001

Vegetables

 

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

 

Asparagus.

Asparagus larvae can now be found feeding on the ferns. In order to help reduce problems for next season as well as reduce plant damage in season, a treatment should be applied if larvae are readily found feeding on ferns. Sevin, Ambush or Pounce will provide control. 

 

Cabbage.

Continue to scout for  diamondback and cabbage looper larvae. Although a mixture of larvae can be found, cabbage looper is the predominant species being found. A treatment should be applied if 5% of the plants are infested and before larvae move deep into the hearts of plants. If both insects are present, Avaunt, a Bt, Proclaim or Spintor will provide control. If cabbage looper is the predominant species, Confirm or a pyrethroid will also provide control.

 

 

Lima Beans.

As soon as pin pods are present, you should sample for earworm, lygus and stinkbugs. All three insects are present in lima beans throughout the state. A treatment should be applied if you find one corn earworm per 6 foot of row or 15 tarnished plant bugs and/or stinkbugs per 50 sweeps. Lannate or Capture can be used to control all 3 insects on lima beans.

 

 

Peppers.

At the present time, all peppers should be sprayed on a 7-day schedule for corn borer, corn earworm and pepper maggot control except in the Laurel area where a 5-day schedule is needed.

 

Snap Beans.

All processing snap beans in the bud and pins stages should be treated with Orthene for corn borer control. Asana or Capture will also be needed at the pin spray for earworm control.  At the present time, two sprays with Asana, Capture or Lannate will be needed between the pin spray and harvest for a combination of corn borer and corn earworm control. Be sure to check local trap catches, which are updated on the IPM website three times per week. (http://www.udel.edu/IPM/traps/latestblt.html).  All fresh market snap beans should be sprayed on a 7-day schedule with Lannate or Capture.

 

Spinach.

Fields should be scouted at emergence for webworm and beet armyworm larvae. Controls should be applied when worms are small and before they have moved deep into the hearts of the plants. Since Lannate cannot be applied before plants are 3-inches in diameter, Ambush, Pounce, Confirm (6-8 oz/acre) or Spintor (4-8 oz/acre) should be used. Generally, at least 2 applications are needed to achieve control of webworms and beet armyworm.

 

Sweet Corn.

All fresh market silking sweet corn should be sprayed on a 3-day schedule throughout the state. The first silk spray is often the most critical. This spray should be applied as soon as ear shanks are visible.

 

 

Vegetable Diseases -  Kate Everts, Extension Vegetable Pathologist, University of Delaware and University of Maryland;  everts@udel.edu

 

MELCAST for Watermelons

EFI Values (Environmental Favorability Index)

Do not use MELCAST if there is a disease outbreak in your field, it is a preventative program.  Any questions, please call David Armentrout at (410) 742-8788 or e-mail: da88@umail.umd.edu

 

Location

8/15

8/16

8/17

8/18

8/19

8/20

8/21

8/22

Bridgeville, DE

2

2

1

3

4

4

1

1

Laurel, DE

(Collins Farms)

5

3

3

4

4

3

3

2

Galestown, MD

6

2

2

3

5

3

2

2

Georgetown, DE

4

3

0

4

4

5

3

 

Hebron, MD

6

4

9

9

8

3

5

3

Salisbury, MD

0

0

0

4

4

4

2

4

Laurel, DE

(Vincent Farms)

3

3

3

2

5

3

3

2

Watermelon Fields should be sprayed with a fungicide when 30 EFI values have been accumulated by the weather station nearest your fields.  Add 2 points for every overhead irrigation.  After a fungicide spray, reset your counter to 0 and start over.  If a spray has NOT been applied in 14 days, apply a fungicide and reset the counter to zero.  The first and last day above can be partial days so use the larger EFI value of this report and other reports for any specific day

 

More detailed information concerning MELCAST and sample data sheets are available on the web at http://www.agnr.umd.edu/users/vegdisease/vegdisease.htm. .     v

 

 

Field Crops

 

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

Alfalfa.

We are starting to see an increase in defoliators in alfalfa, especially webworm activity. Early harvest and diseases can often reduce populations. As a general rule, a treatment may be needed if you find webbing on 25-30% of the terminals, and you are 2 or more weeks from harvest. Most insecticides labeled for leafhopper, except dimethoate, will provide webworm control.

                            

Soybeans.

Corn earworm larvae have been found in soybeans in Kent County and Sussex Counties. We have reports that fields are starting to be sprayed in Virginia. Migratory populations could still result in economic levels in our soybean fields so all fields should be scouted on a weekly basis as soon as pin pods are present. The treatment threshold is 3 per 25 sweeps in narrow fields and 5 per 25 sweeps in wide row fields. When possible, treatment should be delayed until 1/3 of the population is 3/8 inch in size.  A pyrethroid or Larvin will provide control.

 

 

Making the Switch to Organic Production - Richard W. Taylor, Extension Agronomist; rtaylor@udel.edu

 

Although still a small sector of agriculture, organic farming is attracting more and more producer interest.  For growers who are intrigued by the idea and would like background material on organic production in the humid East, I have available a series of video tapes on organic production.  “Organic Grain: Another Way” was developed by John Hall (University of Maryland Cooperative Extension) and the cooperative efforts of the Rodale Institute and the Northeast Sustainable Agriculture---.  The production consists of three VHS tapes entitled “Choosing Organic”, “The Transition to Organic”, and “Farm Decision Making: One Family’s Story”.  Please either contact me directly (email is listed above and my office phone number is 302.831.1383) or through your local county ag Extension agent if you would like to arrange to borrow them.  Running time is about 30 minutes on the first and last tape and 60 minutes on the second tape.

 

Another source of information is the newly formed Delaware Organic Food and Farming Association.  The President is Ron Yoder and the Association holds monthly meetings.

 

Two of the big challenges with switching to organic production are a three-year transition period and the challenge of weed control during the startup years.  Forage production with an aggressive crop and choosing fields that have minimal weed problems (especially with perennial weed species) can make the transition easier although obtaining the proper cultivation tools and learning the proper use of these tools along with their advantages and disadvantages is also important.