Volume 6, Issue 21 August 14, 1998

 

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

Cabbage.

Economic levels of diamondback and cabbage looper can be found in cabbage. Spintor or Bt insecticides will control both insects. A treatment should be applied if 5% of the plants are infested with larvae. Spintor continues to provide excellent control of diamondback larvae at the 2.5 – 3 ounce rate. The higher rate, 3-6 oz per acre, is needed if cabbage loopers are also present.

Lima Beans.

Corn earworm larvae can now be found in lima bean fields. When possible, fields should be scouted twice a week for earworm larvae since populations can increase quickly. No treatment will be needed until you find one corn earworm larvae per 6 foot of row. Lannate is the only labeled insecticide available for earworm control in lima beans. Rate selection will depend on the size of larvae at treatment time. If larvae are small, 1.5 to 2 pts/acre of Lannate LV will provide control. The 3-pt/acre rate should be used if larvae are large. Tarnished plant bug and stink bugs are also active in fields. Once fields reach the pin stage, they should be checked for both adult and immature stages of both insects. Controls are needed if you find 15 tarnished plant bugs and/or stink bugs per 50 sweeps. Lannate should be used if both species are present.

 

Snap Beans.

Processing snap beans should be sprayed at the bud and pin stages with Orthene for corn borer control. In areas where corn borer sprays are in the 2-6 per night range, a third spray with Lannate will be needed 5-7 days from harvest. In the Greenwood area, sprays should be applied on a 5-day schedule from the pin spray until 5 days from harvest. In the Bridgeville area, sprays are needed on a 4-day schedule from the pin spray until harvest. Fresh market snap beans should be sprayed on a 7-day schedule from the pin stage until harvest.

Peppers.

Maintain a 7-10 day schedule for corn borer control, except in the Bridgeville area where sprays are needed on a 5-7 day schedule. Aphids remain active, especially in fields where only a pyrethoid has been used. If aphid populations are starting to increase, Lannate or Orthene should be used.

Sweet Corn.

Fresh market silking sweet corn should be sprayed on a 3-4 day schedule throughout the state. Fall armyworm moth activity is still high (> 200 moths per week in some locations). Be sure to check whorl stage corn for larvae feeding in the whorl. A treatment with Larvin or Warrior should be applied if 15% of the whorls are infested with fall armyworm larvae. Generally, 2 whorl applications will be needed. If Ambush, Pounce or Baythroid is being used as a silk spray, they should be alternated with Lannate or Larvin for fall armyworm control. If Warrior is used, you should increase the rate to 3.84 oz/acre. v

Vegetable Diseases - Kate Everts, Extension Plant Pathologist, University of Maryland and University of Delaware ; everts@udel.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 August 5-12. Any questions please call Phil Shields at (410) 742-8788 or e-mail: ps136@umail.umd.edu

EFI Values

Location

8/5/98

8/6/98

8/7/98

8/8/98

8/9/98

8/10/98

8/11/98

8/12/98

U of M, LESREC
Salisbury,MD
 

2

2

4

4

5

6

5

Wootten Farms, Galestown,MD  

0

4

4

4

5

5

4

Mark Collins, Laurel, DE  

0

4

4

4

5

6

5

U of D, REC Georgetown, DE            

0

2

Vincent Farms Laurel, DE  

0

4

4

5

4

6

4

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

 

Laurel Farmer's Auction Market Report

August 6 -12, 1998

Quantity Produce Price
44,685 Cantaloupes  
 

Athena

0.25-1.45
 

Super Star

0.25-1.05
 

Hales

0.25
 

Passport

0.35-1.45
2252 Honeydews 0.35-1.35
234 Crenshaws 0.50-1.60
7758 Sugar Babies 0.30-1.55
 

Seedless

1.10-1.75
468,924 Watermelons  
 

Crimson Sweet

 
 

12 up

0.30-0.75
 

15 up

0.50-1.25
 

20 up

0.75-1.80
 

25 up

1.25-2.55
 

30 up

2.25
 

Sangria

 
 

12 up

0.50-0.70
 

15up

0.50-1.55
 

20 up

1.00-1.85
 

25 up

1.25-3.00
 

All Sweet

 
 

15 up

0.60-1.25
 

20 up

1.35-1.65
 

25 up

1.50-2.45
 

Royal Majesty

 
 

12 up

0.50-0.55
 

15 up

0.50-1.25
 

Royal Sweet

 
 

15 up

0.50-0.65
 

20 up

1.00-1.35
 

25 up

2.05
 

Royal Star

 
 

15 up

0.55
 

20 up

1.00
 

Starbrite

 
 

20 up

1.50
 

25 up

1.25-1.40
 

Jubilee

 
 

25 up

1.30-1.95
 

30 up

1.70
 

Seedless

0.50-2.75
 

Yellow Dolls

0.35-1.50
57 Peppers  
 

Green

4.00-16.00
1612 Tomatoes  
 

Red

5.00-21.00
 

Pink

3.00-16.00
159 Sweet Corn Doz. 0.80-1.70
37 Lima Beans 4.00-20.00
68 Cucumbers 3.00-9.50
90 Squash  
 

Yellow

3.00-9.50
 

Green

4.00-9.00
18 Potatoes  
 

Red

5.50-6.00

v

 

 

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

Soybeans.

If spider mites are active and you plan to use dimethoate, the addition of an acidifying/penetrant like LI-700 has helped to improve activity on drought stressed fields. In addition, the use of 20 gallons of water has also improved control. If the Section 18 material Danitol is used, we have seen about 2 weeks worth of control with one application. A second application will be needed if numerous eggs were present at the time of the first application. All soybeans should be scouted for podworm activity. No controls will be needed until you find 3 earworms per 25 sweeps in narrow row beans or 5 per 25 sweeps in wide row beans. A pyrethroid or Larvin will provide the most cost-effective control. v

 

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

USDA's August Crop Report Contains Few Surprises

This month's USDA Crop Production Report is the first survey-based production estimate for U.S. corn and soybeans. Ending stocks for both old and new-crop corn are increased over last month's report. Ending stocks for old and new-crop soybeans are decreased slightly from the July report. Ending stocks for new-crop wheat were reduced 49 million bushels from last month.

U.S. corn production is forecast at 9.59 billion bushels, up 2 % from last year and 3 % from 1996. Based upon August 1, 1998 conditions, yields are expected to average 130.0 bushels per acre. If realized, this would be the second largest production and the third highest yield on record. Acreage for harvest is estimated at 73.8 million acres, nearly unchanged from 1997. Ending stocks for old-crop corn were placed at 1.449 billion bushels, while last month's estimate was 1.434 billion bushels. New-crop ending stocks were estimated at 1.851 billion bushels, with the July estimate at 1.844 billion bushels.

Soybean production is forecast at a record high 2.82 billion bushels, up 4 % from last year's record of 2.73 billion bushels. Yield is forecast at 39.5 bushels per acre. Acreage for harvest is estimated at a record 71.6 million acres, up 2 % from 1997. Ending stocks for old-crop soybeans were 210 million bushels, down 5 million bushels from last month's estimate. New-crop ending stocks were placed at 430 million bushels, also 5 million bushels less than last month's estimate.

All wheat production is placed at 2.55 billion bushels, up 1 % from 1997. The U.S. yield is placed at 43.0 bushels per acre, a record high. Ending stocks for old-crop wheat were placed at 723 million bushels, the same as last month. New-crop ending stocks estimated at 819 million bushels, were 49 million bushels less than last month's forecast.

CBT Traders React to Crop Report

While the drop in the bean carryout may be supportive, traders are expected to think that this crop will get larger, which is expected to offset any friendliness of the report. This report did not cover the phenomenally great weather that the corn belt has experienced in August. Virtually no supply problems exist. The U.S. is currently experiencing a demand problem. Corn and soybean prices are not expected to improve any time soon.

v

Are Deer Reducing Your Forage Yields? Richard W. Taylor, Extension Agronomist ; rtaylor@udel.edu

Recently, Dr. Marvin Hall and R. Stout from Penn State reported on a study to evaluate deer damage on forage crops. Deer damage on alfalfa can be substantial and can impact yield, stand survivability, and weed invasion. I can attest to this as every day when I go out for a run I see from two to ten deer grazing in a nearby alfalfa field. They tend to eat from the same corner of the field all the time and the stand there has been reduced greatly.

The Penn State researchers found that the forage crops studied, alfalfa, orchardgrass, timothy, and combinations of alfalfa and the two grasses, when protected from deer feeding averaged 1,660 lb/A more dry matter (DM) than their unprotected counterparts. Total yield reduction ranged from 435 lb/A for pure orchardgrass to 1,230 lb/A for pure timothy to 2,392 lb/A for pure alfalfa. Deer feeding resulted in an average economic loss of $80 per acre for pure alfalfa and $28 per acre for pure orchardgrass. Weed density increased more in the unprotected than in the protected plots of each species or combination of species. Weed density was greatest in the pure alfalfa and least in pure orchardgrass by the second year of the study.

In the study, the researchers planted three different mixture ratios of alfalfa and each grass. Deer grazed alfalfa selectively from alfalfa-grass mixtures and fed on plots containing timothy more than those containing orchardgrass. Averaged across all mixtures, alfalfa made up 35 percent of the total yield in the protected plots but only 19 percent in the unprotected plots. Alfalfa-orchardgrass mixtures had greater economic returns than pure alfalfa only when alfalfa was seeded at 50 percent or greater of the mixture.

Their recommendations were that the use of orchardgrass alone or in a mixture with alfalfa minimizes deer feeding and provides the greatest yields. They caution that when deer feeding occurs, net economic returns will be greater for alfalfa-orchardgrass mixtures because of improved quality compared to pure orchardgrass.

Manganese Deficiencies Still Visible on Soybeans - Richard W. Taylor, Extension Agronomist ; rtaylor@udel.edu

A quick survey of soybean fields this week showed that what appear to be manganese (Mn) deficiency symptoms are still visible in some soybean fields. The problem areas are usually around the headlands where past the lime application rate may be heavier than in the body of the field. These sites can be spot treated with techmangam to supply 1 to 2 lbs actual Mn/A. A few fields have more widespread symptoms or, in some cases, symptoms located in odd shaped patterns that may be related to soil texture. In all cases, confirm that the problem is Mn deficiency using either a tissue test or a soil test since soybean cyst nematodes can cause symptoms similar to those of Mn deficiency.

If soybeans are at the R5 or R6--pod-filling--growth stage, Mn applications may not help yield potential; but if they are still in the bloom (R1 or R2) or early pod set (R3 and R4) stage, soybean yields can be increased by a foliar Mn application. v

 

 

 

Attention Delaware Farmers

Irrigation Field Day

Managing Irrigation for Crop Performance and Efficient Water Usage

Date: Wednesday, August 26, 1998

Place: T.G. Adams & Sons farm, Road 583, between Greenwood and Bridgeville, DE

Time: 9:00 A.M. to noon

Meal: A barbecue pork and chicken picnic lunch will be provided

All Delaware farmers interested in irrigation are invited to aftend a field day on managing irrigation for crop performance and efficient water usage. This field day, sponsored by the University of Delaware Cooperative Extension, will be held on Wednesday, August 26,1998 at T.G. Adams & Sons farm, Road 583, between Greenwood and Bridgeville, DE from 9:00 A.M. to noon. A picnic style lunch will be provided at noon. This meeting will focus on large overhead irrigation systems (pivots, guns, laterals) and best management practices for irrigation. Topics will include:

Talks and demonstrations will be presented by University of Delaware researchers, specialists, and agents. We will also have Paul Bodenstine an irrigation consultant with Ag Systems Consulting, Norfolk, VA to talk about his experiences with irrigation management.

Please register in advance (so we know how many meals to provide) by calling the Kent County Cooperative Extension Office at (302) 697-4000. Anyone that is interested is welcome to aftend. For additional information or special assistance in accessing this meeting contact Gordon Johnson at the above number.

Hope to see you there.

Gordon Johnson - Extension Ag Agent, Kent County

Carl Davis - Extension Ag Agent, New Castle County

Derby Walker - Extension Ag Agent, Sussex County

 

Week of August 7 to August 13

Rainfall:
1.21 inches; August 10
0.02 inches; August 11
Readings taken for the previous 24 hours at 8 a.m.
Air Temperature:
Highs Ranged from 91 F on August 10 to 82 F on August 7.
Lows Ranged from 67 F on August 7 to 71 F on August 11.
Soil Temperature:
82.3 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 College and the United States Department of Agriculture cooperating, John C. Ne, 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.