Volume 7, Issue 21                                                                                     August 20, 1999


Vegetables

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

Cabbage.

Economic levels of diamondback and cabbage loopers can be found in cabbage fields. Spintor or Bt insecticides will control both insects. Confirm is now labeled on cabbage and will provide good cabbage looper control at the 8 oz per acre rate. A treatment should be applied if 5% of the plants are infested with larvae. Spintor will provide excellent control of diamonback larvae at the 3-ounce rate. The higher rate, 4-6 oz per acre, is needed if cabbage loopers are also present.

Lima Beans.

Corn earworm, lygus and stinkbugs can all be found in the earliest planted fields. 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. If corn earworm vary in size at the time of treatment, 2-3 pt of Lannate LV will be needed and at least 3 ounces of Capture should be used.

Peppers.

Maintain a 7-10 day schedule for insect control. Lannate will be the best choice to control corn borer, corn earworm and aphids. Remember that Orthene does not provide effective earworm control.

Snap Beans.

Processing snap beans should be sprayed at the bud and pin stages with Orthene for corn borer control. Capture applied at these same timings has also provided corn borer and corn earworm control. If Orthene is used at the pin spray, Asana or Capture will also be needed for corn earworm control. At this time, 2 applications of Lannate or Capture on a 5 day schedule will be needed between the pin spray and harvest except in the Greenwood and Laurel areas where sprays will be needed on a 4 day schedule.

Spinach.

As soon as plants emerge, begin scouting small plants for webworms 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, a Bt insecticide and now Confirm (6-8 oz/acre) should be used. Confirm received a label this spring and in spinach trials has provided good beet armyworm and webworm control. Generally, at least 2 applications are needed to achieve control of webworms and beet armyworm.

Sweet Corn.

Fresh market silking sweet corn should be sprayed on a 3-day schedule throughout the state. If Ambush, Asana or Pounce are being used, you should combine the mid-range rate of these pyrethroids with Lannate or Larvin to control the complex of corn borers, corn earworms, and fall armyworm. If fall armyworm pressure is high in your area, you will need to alternate the high rate of Baythroid or Warrior with Lannate or Larvin at this time.


Lima Bean Downy Mildew - Ed Kee, Extension Vegetable Crops Specialist, kee@udel.edu

Dr. Tom Evans and his graduate student, Carley Davidson, are conducting research with Downy mildew on lima beans. If you see Downy mildew, please call Tracy Wootten or myself, and we will contact Carley to come collect samples. She and Dr. Evans are very interested in furthering our understanding of Downy mildew, the different races, and its control. Collecting samples from the field is critical to their research, so please call if you see Downy mildew on lima beans. Thank you.


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

Spinach.

Fall spinach plantings should be treated with Ridomil Gold to minimize damping off. Ridomil Gold 4E should be applied as a soil surface application after seeding. This application also will provide early season control of white rust. Several mid-Atlantic states (including Delaware and Maryland) applied to the EPA for Section 18 emergency registration for the use of Quadris for white rust of spinach. The EPA has denied this registration and Quadris cannot be used this fall.

 

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 11– August 18. Any questions please call Phil Shields at (410) 742-8788 or e-mail: ps136@umail.umd.edu

 

EFI Values for 1999

Location

8/11

8/12

8/13

8/14

8/15

8/16

8/17

8/18

U of M, LESREC
Salisbury,MD

2

5

4

2

5

2

5

3

Wootten Farms, Galestown,MD

0

4

4

2

5

1

4

2

Mark Collins,
Laurel, DE

2

4

4

3

5

0

4

3

Vincent Farms Laurel, DE

2

3

3

2

5

0

4

2

D C Farms,
Bridgeville, DE

0

4

4

2

5

1

4

2

Balvin Brinsfield,
Vienna, MD

1

2

2

1

5

0

4

1

Charles Wright,
Mardela Springs, MD

2

3

3

2

5

2

4

2

U of D, REC Georgetown, DE

0

3

4

2

5

3

5

1

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.


Laurel Farmer's Auction Market Report

August 12, 1999 – August 18, 1999

Quantity

Produce

Price

17,796

Cantaloupes

 
 

Athena

0.25-1.00

 

Super Star

0.45

Cordell

0.35

5985

Sugar Babies

0.30-1.10

115

Crenshaws

0.50

1239

Honeydews

0.25-1.05

150

Yellow Dolls

0.30-.35

474,723

Watermelons

 
 

Crimson Sweet

 
 

15 up

0.50-0.60

 

20 up

0.60-2.05

 

25 up

1.05

 

Sangria

 
 

12 up

.40

 

15 up

0.50-.75

20 up

0.60-2.50

 

25 up

.90-1.30

 

All Sweet

 
 

15 up

.50-.60

20 up

.65-2.25

25 up

1.20-1.95

 

Seedless

0.50-1.15

85

Peppers

 
 

Green

4.00-7.00

 

Red

7.00-7.50

 

Bell

3.00

 

Jalapeno

5.00-6.00

33

Eggplant

3.00-7.00

1353

Tomatoes

 
 

Red

4.00-9.50

 

Pink

4.00-10.00

92

Cucumbers

3.00-11.50

132

Squash

 
 

Yellow

3.00-10.00

 

Green

3.00-11.00

28

Potatoes

 
 

Red

3.50-8.00

12

Lima Beans

17.50-33.00


Field Crops

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

Soybeans.

Small corn earworms can now be found in soybean fields in the bloom to early pod-set stages in Sussex County. No controls should be needed until 1/3 of the worms are ˝ inches in size and the first signs of pod feeding are detected. The treatment thresholds are 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.


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

Soybeans.

Several disease problems have been diagnosed during the past week. The dry weather has predisposed soybean plantings to infection by the charcoal rot fungus. This disease causes wilting of soybeans before flowering. The plants wilt and leaves remain attached to the plant. After flowering, plants wilt and a silvery to light gray discoloration of the lower stem is visible. At both times the small microsclerotia of the fungus can been seen in the bark and in the pith of the older plants if
split open. These fungus fruiting structures resemble fine powdered charcoal thus the name charcoal rot. I have seen small groups of plants infected and in double-cropped beans large areas that are wilted and dead. Control depends primarily on a three- year crop rotation with small grains, corn and/or sorghum, or vegetables other than snap or lima beans.

The other disease recently seen is stem canker. This fungus disease produces large brown to black sunken areas on the stem (cankers). Leaf symptoms develop that are characteristic of plants not receiving enough water, including marginal leaf burn and a wilting of the growing point (shepherd's crooking). Infected plants may occur in small groups or large areas. Infections can occur early in the season and remain dormant until later when symptoms appear. Normally late maturing varieties are less susceptible, but planting resistant varieties and crop rotation are the best control.

Soybeans that were planted late because of a lack of rain or after barley are now flowering and the soybean cyst nematode is very visible on the roots of susceptible plants. Yellow and white females can be seen easily especially in areas that received some rain. Check your plantings if you see stunted yellow plants, or areas with uneven growth. Low levels of SCN will not produce yellowing and stunting, but plants will be smaller and not fill the rows. Rotation with resistant varieties or non-hosts such as corn or sorghum is suggested.


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

Grain Markets Remain Choppy Going Into September Crop Report
Want to guess the size of the 1999 U.S. corn crop? Pick a number: 9.1, 9.2, 9.3, etc. billion bushels. The next crop report will tell it all in terms of the nation’s 1999 corn and soybean production. Since a chance remains that the production estimates for corn and soybeans can be lowered, then we have a chance for corn and soybeans to rally somewhat between now and shortly before or after the issuance of the September report. There are a few other reasons for this line of reasoning, first, most of the FSA loan corn and beans have worked their way out of the loan and probably sold. Second, we are not going to grow a 10 billion bushel corn crop, and it is not quite certain just where the final
production forecasts will come in. However, this particular year where we end up on the range in the current price range forecast depends on the numbers in the September crop report.

Midwest basis is wide and reminds us that we have a large supply (more than adequate) of corn and beans on hand. Corn belt farmers will be looking to store grains going into harvest with a wide basis. Local basis bids will hold a key in directing local farmers whether and when to be sellers of corn and beans this fall. Currently, Dec '99 corn futures are expected to range from $2.10 to $2.50 per bushel, depending upon crop development into September. November bean futures are expected to trade in a range from $4.73 to $5.50 per bushel.


Fall Fertilization of Forage Hay Crops - Richard W. Taylor, Extension Agronomist; rtaylor@udel.edu

Recent rains in many areas of the state mean that a late-summer harvest may be obtained off hay fields. To prepare these fields for the winter, the second application of potash fertilizer (potassium) should be applied after the late-summer harvest. Potassium is needed by the forage to protect itself from freezing injury during the winter. Think of it as the plant’ antifreeze. Just as you prepare your vehicle by checking and replacing the antifreeze, you should do the same for your hay and pasture fields.

The amount of fertilizer that will be needed will depend on your previous fertilization program and your soil test value. If you do not have a recent soil test to work from, consider taking a soil sample and getting it analyzed now so you can know for sure how much potash to apply to each field. Also look at the field’s pH and if lime is needed now may be a good time to apply it. Fields are generally firm and will support the weight of the lime truck at this time of year versus in the spring when soils often are wet and loosened from the effects of freezing and thawing during the winter. For legume fields (alfalfa, in particular), a second application of boron can be made with the late-summer potash fertilizer. For alfalfa, apply 1 to 1.5 pounds of actual boron per acre blended with the potash.


Stockpiling Forage for Late Fall/Early Winter Grazing - Richard W. Taylor, Extension Agronomist; rtaylor@udel.edu

To extend the number of days you can graze animals, consider stockpiling forage now for late fall and early winter grazing. In this system, the grass is not grazed after August 1 and is allowed and encouraged to make as much growth as possible before a killing frost. This forage essentially then is stockpiled in the field for use after other grazing is no longer available. Tall fescue is the species that holds its quality the best under this system. The leaves accumulate sugars and the accumulated forage can be quite high in quality. Another species grown in this area that can be used is orchardgrass. Orchardgrass that has been stockpiled does not maintain its value as well as tall fescue but can grow enough to justify its use in this system.


Upcoming Meetings…

Commercial Forage Production Field Day

Establishing and Maintaining Alfalfa and other Forage Crops

Date: Tuesday, August 24, 1999

Place: Thomas Farms, 896 Sandy Bend Road, Marydel, DE

Time: 9:30 A.M. to 11:30 A.M.

Please register in advance by calling Kent County, DE Cooperative Extension Office at (303) 697-4000 by August 23, 1999. Anyone that is interested is welcome to attend. For additional information or special assistance in accessing this meeting contact Gordon Johnson at (302) 697-4000.

(See Issue 19 for more details).


                    Weather Summary

Week of August 13 to August 18

Rainfall:

FINALLY!!!

2.30 inches: August 14, 1999

0.06 inches: August 15, 1999

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

Air Temperature:

Highs Ranged from 92°F on August 13 to 83° F on August 16.

Lows Ranged from 74°F on August 13 to 69°F on August 17.

Soil Temperature:

84 °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. 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.