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.  Another area too often overlooked is planning ahead by developing both a marketing strategy and marketing contacts.  Many of the successful organic growers actually produce between ten and twenty different crops plus employ a number as green manure crops to build soil organic matter.  Finding markets for that many crops is indeed a challenge, but when properly met it can lead to a profitable business.

 

As with any new enterprise, before making the move, you will need to learn as much about the potential pitfalls, marketing opportunities, advantages, and disadvantages as possible.  These days there is at least a small base of knowledge available to help you so ask around and take advantage of that expertise.

 

 


Late Summer/Early Fall Legume and Grass Hay Field Management - Richard W. Taylor, Extension Agronomist; rtaylor@udel.edu

 

An important management consideration is when to take the last late-summer/early-fall harvest on legumes such as alfalfa and red clover.  Legumes do best if they have a 6- to 8-week rest period prior to the first killing frost in the fall.  This period allows the crop to accumulate energy reserves for winter survival.  A killing frost is not the only consideration either.  As fall progresses, the number of hours of sunlight becomes less until the combination of short days and cool/cold temperatures shuts down a crop.  Before the shutdown occurs, legumes must store enough sugars and carbohydrates to stay alive over the winter months.

 

Backing up from the average date of the first fall frost, the cut off date that we use is between Sept. 10 to Sept. 20.  When possible, the last harvest is ideally taken in the last week of August or the first week of September to provide that little bit of cushion in case of an early killing frost.  In a year such as this one when drought or heavy rains (depending on which end of the state you farm in) has disrupted harvest schedules or reduced yields to the point that a late-summer/early-fall harvest is needed, observing the cutoff date is important.

 

Finally, the other management tool available for preparing the crop for the winter is the application of potassium, phosphorus, and boron following the August harvest.  Apply the second split of fertilizer to legume crops following an early- to mid-August cut (first preference) or following the last harvest before the September cutoff date if the previous harvest was taken in July.  Fall fertilization (after the September deadline for cutting) does not benefit the crop to any extent since the shorter days and cooler temperatures have slowed root growth and nutrient uptake.  As with a fertility program for any crop, be sure to have an up-to-date soil test result on which to base your fertilizer applications.  Help is available from many sources now for creating your own nutrient management plans, so take advantage of the opportunity and make the most of your fertilizer dollars.

 

Another management option, if available for the particular forage crop you grow, is eliminating or reducing weed pressure so the forage will obtain the maximum benefit from the available sunlight, soil moisture, and soil nutrients.  In fields with combinations of grasses and legumes, selective herbicides are not available but using best management practices for fertility programs, harvest management, pest management, and crop renovation will help minimize negative weed impacts.

 

 


Grain Marketing Highlights - Carl German, Extension Crops Marketing Specialist; clgerman@udel.edu

 

Weekly Crop Condition Ratings Reduced Again
Weekly crop ratings were reduced a second week in a row for the 2001 U.S. corn and soybean crops, as reported Monday, August 20th. The nation's corn crop is now rated as 54% good to excellent, as compared to 57% last week and 69% last year. One of the largest declines in the corn crop rating, for the past week, was noted in Illinois (generally the second largest corn producing state in the nation, just behind Iowa, and just ahead of Indiana), with a 10% decline reported. Crop condition ratings for the U.S. soybean crop were placed at 52% in the good to excellent category, compared to 54% last week and 62% last year.

General Comments
The decline in crop condition ratings was reported to have caught commodity traders by surprise, although many market analysts have been anticipating the decline due to the extreme weather conditions that have been experienced across the U.S. over the past several weeks. Many analysts are currently realizing that USDA's August 10th supply and demand estimates for the 2001 corn and soybean crops were likely to be too high, with some forecasters beginning to estimate the nation's corn crop size to be more near 8.9 to 9 billion bushels, with a soybean crop size of near 2.8 billion bushels.

Commodity prices are expected to improve in the near term from current levels. The market is currently supply driven and is expected to remain that way until just before, during, or just after harvest. This means that a market that is 'purely' a supply driven bull market is likely to set highs during this time period (short crops have long tails). The exact period for when to expect the price to peak depends upon how the weather effects the remainder of the development of the crop, and how well past weather events have already been accounted for in the crop size estimates released thus far. However, other factors are likely to have a positive effect upon 2001 commodity prices as we approach harvest. Crop size predictors are beginning to indicate more strongly that frost occurring even on a normal date in the northern tier of the corn belt (namely Michigan, generally the fifth largest corn producing state) is likely to have a negative impact on yield, due to the late maturity of the crop. The second factor has to do with the declining value of the dollar, which has been declining noticeably since the first of July. A weaker dollar makes U.S. commodities a good buy for foreign currencies, which strongly suggests that once we complete the current supply driven market that traders will then be bidding commodity prices based upon a demand driven bull market. The bottom line is to wait a while longer before advancing 2001 corn and soybean sales.

 

 


Yellow Soybeans with Roundup-Ready Soybeans - Mark VanGessel, Extension Weed Specialist;  mjv@udel.edu

 

It is not uncommon to get slight yellowing in the growing points of soybeans shortly after spraying glyphosate on Roundup-Ready soybeans.  This year it seems to be more dramatic and more widespread than in past years particularly for late planted or double-cropped beans that were sprayed a week or two prior to the big rains.  It seems to be worse with the new formulation of Roundup Ultra Max than the other forms of glyphosate.  It also is worse where there were overlaps or in the turn rows.  The beans will grow out of the symptoms fairly quickly.  The yellowing does not affect the height of the beans or vigor.

 

 


                       Weather Summary

Week of August 16 to August 21, 2001

Rainfall:

 

1.09 inches: August 18

 

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

Air Temperature:

Highs Ranged from 86°F on August 17 to 81°F on August 21.

Lows Ranged from 70°F on August 17 to 61°F on August 16.

Soil Temperature:

81°F average for the week.

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

 

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

http://www.rec.udel.edu

 


Compiled and Edited By:

Tracy Wootten

Extension Associate - Vegetable Crops

 


Cooperative Extension Education in Agriculture and Home Economics, University of Delaware, Delaware State University and the United States Department of Agriculture cooperating, John C. Nye, Dean and 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.