Volume 7, Issue 15                                                                                            July 9, 1999


Vegetables

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

Peppers.

Maintain a 10-day schedule on all peppers with fruit that is inch in size or larger. Orthene will provide corn borer and pepper maggot control. Lannate or a pyrethroid plus dimethoate will control the same insect complex.

Potatoes.

Economic populations of green peach aphids can be found in a few fields throughout the state. The treatment threshold is 4 aphids per leaf until 2 weeks from harvest when this threshold increases to 10 aphids per leaf. Since the green peach is the predominant species being found, Provado or Monitor are the materials of choice.

Snap Beans.

At this time processing snap beans should be sprayed with an application of Orthene at the bud and pin stages in the Bridgeville, Dover, Greenwood, Rising Sun and Seaford areas. Fresh market snap beans in those same areas should be sprayed on a 7-day schedule with Lannate.

Sweet Corn.

Fresh market silking sweet corn should be sprayed on a 3-4 day schedule in Sussex County and on a 4-5 day schedule in Kent and New Castle Counties.

Melons.

Mites remain active in many fields with an increase in egg laying activity as a result of the hot weather. If you plan to use Agri-Mek for spider mite control, it should not be used with an adjuvant like Plex, which may inhibit its movement into the leaves. Although it worked well last year, new information indicates that this would not be the best adjuvant to use. Materials like LI-700, AD-100, Silwet or Silken have worked well with Agri-Mek. In addition, Novartis suggests that it should not be used with fungicides with pinolene stickers. Recent applications of dimethoate or Kelthane plus an organosilicone by air have provided effective control of mites. These materials should not be used more than twice in a row to prevent the development of resistance. Melon aphid populations have also started to increase in spots throughout fields. Populations can explode quickly so be sure to check fields carefully, especially later planted fields. The treatment threshold is 20% infested plants with 5 or more aphids per leaf or runner. Lannate or Thiodan will provide melon aphid control but coverage is important, especially if leaves have begun to curl. v


Vegetable Diseases - Bob Mulrooney, Extension Plant Patholgist ; bobmul@udel.edu

LATE BLIGHT REPORT

DSV accumulations as of July 7, 1999 are as follows:

Location/

Emergence Date

DSV’s

July

5

DSV’s

July

7

Recommendation

P-Day

Value for Early Blight Prediction*

Baldwin – 4/19

85

85

10-day, mid rate

563/568

Jackewicz – 4/30

77

77

10-day, mid rate

512/515

Art Wicks – 4/26

76

76

10-day, mid rate

531/538

Ken/Chris Wicks – 5/3

71

71

10-day, mid rate

495/501

*bold is current value/ regular is previous report value.

The recent hot weather is favoring bacterial vine decay as mentioned in the last report. The

bacteria may be Erwinia,, Pseudomonas or Xanthomonas. Unfortunately there is no remedy

for this problem. A return to cooler temperatures would help. v


Vegetable Diseases - Kate Everts, Extension Vegetable Pathologist, University of Delaware and University of Maryland; everts@udel.edu and Phil Shields University of Maryland; ps136@umail.umd.edu

MELCAST for Fungicide Application on Watermelons.

Do not use MELCAST if there is a disease outbreak in your field, it is a preventative program. Below are the EFI values from weather stations located on the Eastern Shore June 30 - July 7. Any questions please call Phil Shields at (410) 742-8788 or e-mail: ps136@umail.umd.edu

EFI Values for 1999

Location

6/30

7/1

7/2

7/3

7/4

7/5

7/6

7/7

U of M, LESREC
Salisbury,MD

5

6

0

1

1

1

2

0

Wootten Farms, Galestown,MD

6

6

0

1

1

1

2

1

Mark Collins,
Laurel, DE

6

7

0

3

5

2

3

1

Vincent Farms Laurel, DE

5

5

0

0

0

0

1

0

D C Farms,
Bridgeville, DE

5

3

0

1

4

1

2

1

Balvin Brinsfield,
Vienna, MD

5

5

0

1

0

1

2

1

Charles Wright,
Mardela Springs, MD

5

4

0

0

1

0

2

1

U of D, REC Georgetown, DE

3

2

0

1

0

0

0

0

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. v


Field Crops

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

Alfalfa

Continue to scout fields for potato leafhopper adults and nymphs. If fields have already turned yellow, it is generally best to cut the field and spray when re-growth is one to two inches tall. Although the rain last week may have slowed down populations, we are starting to see a rapid increase in adult and nymphal activity due to the warm temperatures. If plants are stressed, Baythroid or Warrior will provide the best control.

Soybeans.

Sample fields carefully for spider mites. We are starting to see an increase in populations as a result of the recent hot weather. In general, populations can be found throughout fields and are not confined to field edges. A treatment will be needed when you find 20-30 mites per leaflet and/or 10% of the plants exhibiting mite damage (light stippling not severe damage). If you plan to use dimethoate by ground, the best results in recent years have been obtained with the use of an acidifier/penetrant like LI-700 or AD-100. These adjuvants should be added to the tank before the dimethoate. Parathion can still be applied by air but will only provide contact control. We have received our Section 18 for the use of Danitol 2.4EC for spider mite control on soybeans. It should be used at a rate of 16 oz per acre in a minimum of 10 gallons of water per acre. A maximum of 2 applications per acre may be applied and there is a 30-day pre-harvest interval.

v


Grain Marketing HighlightsCarl German, Extension Crops Marketing Specialist: clgerman@udel.edu

Commodity Prices Continue Posting New Lows
December 1999 corn futures bidding at $2.05 per bushel (not a new low) is 86 cents below the life of the contract high and just 5 cents above the life of the contract low. December wheat futures bidding at $2.66 per bushel, also not a new low, is within 5 cents of the life of the contract low. November soybeans bidding at $4.22 per bushel are just 6 cents off of the life of the contract low as of July 8, 1999. The current commodity price qoutes are bidding spot prices in many areas of the country that are at their lowest levels in 24 to 27 years, depending upon which commodity is being considered.

Use Caution When Considering Speculative Positions
Many farmers are beginning to think in terms of buying back some previously sold grain in the form of futures contracts or call options. Several things have to happen before that strategy can be safely
employed. First, commodity prices must stop their downward spiral. Second, check to see if a sustained rally is expected. Using wheat as a case in point, some market analysts believe wheat prices to be at or near their bottom, yet are not prepared to forecast a sustained rally. Third, confer with both fundamental and technical market analysts before making any decision to buy paper. Taking the LDP and investing the money from sold grain in an interest bearing transaction or account may prove to be the best strategy, at least for the time being.

Update FSA Recording Requirements
The deadline to report planted acres of corn, soybeans and any other spring planted crop is August 5, 1999. Reports made after that date require FSA to impose a fee and to visit the farm and verify late-filed reports. Crop reports are required for farms that are in the AMTA program and they are required to be eligible for LDP's. Contact the county FSA office to address specific questions v


Touchdown Injury on Roundup Ready Soybeans Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

In some of my test plots I have observed soybean leaf injury from Touchdown applications. The injury is brown, dead spots on the leaves. Only the young leaves at time of application are affected. New growth shows no symptoms. The plots were treated under hot, humid conditions without a surfactant. Less than 10% leaf injury was observed.

 

Crop Diagnostic Field Day

Crop Diagnostic Field Day will be held at UD Research and Education Center on July 29 starting at 8:15 a.m.. Three Continuing Education Unit Credits will be awarded for Certified Crop Advisors. The field day is designed to improve diagnostic skills and will focus on commercial vegetables and fruit. Pre-registration is required along with a $25 registration fee. For more information contact Mabel Hough at 302/856-7303. v


Upcoming Meetings…

Crop Diagnostic Field Day

July 29, 1999

8:15 a.m.

U of D Research and Education Center

For more information: contact Mabel Hough at (302) 856-7303.

 

University of Delaware Farm and Home Field Day

August 11, 1999

8:30 a.m. – 1:30 p.m.

For more information: contact

Mark Isaacs or Jay Windsor at

(302) 856-7303.


                   Weather Summary

Week of July 1-July 8

Rainfall:
0.05 inches:July 1,1999
0.03 inches:July 3,1999
Readings taken for the previous 24 hours at 8 a.m.
Air Temperature:
Highs Ranged from 100F on July 6 to 87F on July 1.
Lows Ranged from 79F on July 5 to 71F on July 1 and 8.
Soil Temperature:
83F 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 College 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. 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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