Volume 9, Issue 20 August 10, 2001
Vegetables
Vegetable Insects
- Joanne
Whalen, Extension IPM Specialist; jwhalen@udel.edu
Cabbage.
Economic levels of diamondback and cabbage looper larvae can both be found in fall cabbage. A treatment is recommended when 5% of the plants are infested with larvae. If both species are present, Avaunt (3.5 oz/acre), a Bt, Proclaim (3 oz/acre), or Spintor (4-5 oz per acre) will provide control. If cabbage looper is the predominant species, a pyrethroid or Confirm (8 oz/acre) will also provide control.
Cucurbits.
Striped cucumber beetle and squash bug populations continue to be found in cucurbits. Both can cause defoliation and damage to the rinds of fruit. A treatment should be applied for cucumber beetles if populations are increasing and before rind damage occurs. A treatment should be applied for squash bugs if you find just one egg mass per plant or when nymphs are first detected. Thiodan or a pyrethroid generally provide effective cucumber beetle control; however, multiple applications may be needed. Multiple applications of the highest labeled rate of a pyrethroid are generally needed for squash bug control.
Lima Beans.
Corn earworm larvae can now be found in the earliest planted lima beans. As soon as pin pods are present, you should sample for earworm, lygus and stinkbugs. 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 that have fruit ½ inch in size or larger should be sprayed on a 7-10 day schedule for corn borer and pepper maggot control. A continuous pyrethroid program should not be used to avoid aphid explosions.
Snap Beans.
All processing snap beans in the bud and pins stages should be treated with Orthene for corn borer control. A third treatment with Asana, Capture or Lannate will be needed within a week of harvest. If corn borer catches increase, multiple applications will be needed between the pin spray and harvest. In addition, when corn earworm catches increase to 10 per night, a pyrethroid should be combined with Orthene at the pin spray. As soon as pin pods are present, fresh market snap beans should be sprayed on a 7-day schedule with Lannate or Capture.
Sweet Corn.
All fresh market silking sweet corn should be sprayed on a 3-4 day schedule throughout the state.
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Lima Bean Irrigation- Ed Kee, Extension Vegetable Crops Specialist; kee@udel.edu
As lima beans begin to flower and set pods, remember they
can use 0.25 to 0.33 inches per day when temperatures are in the 90s. It has been demonstrated in research and in
commercial settings that keeping adequate soil moisture is important to
obtaining good yields, especially on earlier beans that may undergo more heat
stress.
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Daily Price Report for Laurel Auction Market
Prices for daily
sales at the Laurel Auction Market are available at the following website:
http://www.delmarvaproduce.com

At the mainpage,
click on Daily Price Report and select the date you wish to review. The following is an example of the price
listings:

Users can sort lots
by produce type for specific produce items. Size, weight, unit price quantity,
and lot price information are also included.
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Vegetable Diseases
- - Bob Mulrooney,
Extension Plant Pathologist; bobmul@udel.edu
Late Blight Update
|
Date |
Total DSV |
Spray Recommendation |
|
5/16 |
0 |
|
|
5/17 |
11 |
|
|
5/20 |
29 |
|
|
5/30 |
51 |
5-day, low rate |
|
6/3 |
57 |
5-day, low rate |
|
6/5 |
57 |
5-day, low rate |
|
6/7 |
57 |
7-day, low rate |
|
6/11 |
59 |
10-day, mid rate |
|
6/13 |
60 |
10-day, mid rate |
|
6/17 |
76 |
7-day mid rate |
|
6/20 |
76 |
7-day high rate |
|
6/24 |
88 |
7-day high rate |
|
6/27 |
88 |
7-day high rate |
|
7/1 |
89 |
10-day, high rate |
|
7/4 |
90 |
10-day, high rate |
|
7/8 |
92 |
10-day, high rate |
|
7/11 |
94 |
10-day, high rate |
|
7/15 |
94 |
10-day, high rate |
|
7/18 |
99 |
7-day, high rate |
|
7/22 |
102 |
7-day, high rate |
|
7/25 |
106 |
10-day, high rate |
|
7/30 |
116 |
5-day, mid rate |
|
8/1 |
117 |
5-day, mid rate |
|
8/6 |
120 |
7-day, high rate |
This will be the last regular late blight report for 2001. With this week’s 90°F + forecast late blight will not be an issue for Delaware growers. No one in the region reported late blight on potatoes again this season.
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Vegetable Diseases - Kate
Everts, Extension Vegetable Pathologist, University of Delaware and University
of Maryland; everts@udel.edu
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 |
8/1 |
8/2 |
8/3 |
8/4 |
8/5 |
8/6 |
8/7 |
8/8 |
|
Bridgeville, DE |
1 |
1 |
2 |
2 |
3 |
4 |
1 |
0 |
|
Laurel, DE (Collins Farms) |
1 |
1 |
3 |
4 |
4 |
7 |
2 |
3 |
|
Galestown, MD |
1 |
1 |
3 |
2 |
2 |
6 |
2 |
2 |
|
Georgetown, DE |
1 |
1 |
3 |
3 |
4 |
4 |
2 |
1 |
|
Hebron, MD |
1 |
2 |
3 |
2 |
3 |
7 |
3 |
3 |
|
Salisbury, MD |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Laurel, DE (Vincent Farms) |
1 |
1 |
2 |
2 |
2 |
3 |
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
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
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Field
Crops
Field Crop Insects - Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu
Soybeans.
Our survey of field corn for earworm infestations shows that resident populations are low compared to last year. In 2000, infestation levels ranged from 5 -80% infested plants. Current infestation levels range from 2 to 15% infested plants. This survey only gives an indication of the potential for earworm infestations in soybeans. Local weather conditions and weather systems from the south could result in high populations in a short period of time. As corn dries down, we will also see an increase in egg laying, especially in open canopy, blooming soybeans. 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 at least 1/3 of the worms are at least 3/8-inch long. A pyrethroid or Larvin will provide control. Continue to watch for grasshoppers and other defoliators including green cloverworm in double-cropped beans. The treatment threshold is 30% prebloom and 15% at bloom.
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Clipping Pastures - Richard W. Taylor, Extension Agronomist; rtaylor@udel.edu
For ruminant animal producers, now is an ideal time to consider clipping your pastures if you are not in an intensive grazing system. If you do practive intensive grazing, you will have already clipped all your pastures at least once and probably several times. For all other grazing managers, clipping pastures is an ideal way to help with weed control as well as stimulate new nutritious forage for your animals to use for growth. For consultants, if you do not already advise your clients that graze animals on the value of clipping their pastures periodically, now is an excellent time to discuss the benefits of this practice with clients.
Why clip now? If you go out into your pastures, you’ll see that many broadleaf weeds (pigweed, lambsquarter, smartweeds, and others) and the annual summer grasses like giant foxtail are beginning to produce flowers. Other things such as curly dock have already seeded so we’re a bit late to control them. Another early concern is in pastures with tall fescue especially if any of the fescue plants are infected with the endophyte fungus that causes animal performance problems. To slow the increase in the incidence of the fungus in pastures containing tall fescue, it’s a good idea to always mow whenever you begin to see seedheads appearing on fescue plants. The endophyte bestows a competitive advantage in fescue plants and this helps them produce seed even under poor growing conditions as well as helps the new seedlings survive and establish. Mowing fescue that is going to seed will help slow the increase in infected plants.
Mowing, therefore, will help reduce the amount of weed seed added to the soil’s weed seed bank and when combined with other good management practices will reduce the amount of weed competition in your pastures. Another reason to clip now, is to remove old growth and stimulate the release of crown and axillary buds in legumes and grasses so new, high quality forage will be produced. For those producers located in areas that have not been as lucky in receiving rainfall this season, mowing will reduce (although it will be a marginal reduction) the forage mass that will be transpiring water and provide material to cover bare soil spots to reduce evaporation.
I’ve already covered some of the benefits of mowing but it might be worth listing some of them. First, mowing will remove old or mature growth that is both low in quality and low in palatability. Second, mowing will stimulate new growth that is highly nutritious and much more palatable to grazing animals. Third, mowing can help control weed competition and keep additions to the weed seed bank at low levels. Fourth, the mowed material will reenter the recycling system in the pasture and help recycle nutrients and add organic matter to the soil. Fifth, mowing may at least marginally reduce moisture loss from the soil and plant canopy.
After mowing and if soil moisture is available, consider adding your second application of potassium as well as a little boron (0.5 to l lb B/A) if the pasture contains legumes. Also, there’s still time for more growth before the fall so another nitrogen application can help stimulate regrowth. This is also the ideal time with tall fescue pastures and to some degree orchardgrass pastures to begin setting aside acreage for fall-accumulation of these grasses for late fall and early winter grazing. More on that topic next week.
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Grain Marketing Highlights - Carl
German, Extension Crops Marketing Specialist; clgerman@udel.edu
Commodity Markets Await August Crop Report
USDA will release the August supply and demand estimates at 7:30 a.m. (8:30
a.m. ET) on Friday, August 10th. With pre report private forecasts all over the
water front in terms of projected crop size, commodity traders have elected
this week to wait and see what USDA's report says. Traders will be most
interested in the ending stocks estimates for corn and soybeans. Once the
report is issued, it will become necessary to determine whether deteriorating
crop conditions that have occurred this week across the U.S. are accurately
reflected in the production estimates. It is very likely that we will have a
lag between the crop size that is projected in tomorrow's report and the
obvious deterioration in the U.S. crop that has occurred again this week.
Nevertheless, the market is currently awaiting the direction it needs that the
August report should entail. Further new crop corn and soybean sales should be
placed on hold.
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UPCOMING MEETINGS:
Crop Diagnostic Field Day
August 15, 2001
8:00 a.m. – 11:30 a.m.
U of D Research & Education Center,
Georgetown, DE

For more information, to register or for directions, contact Lisa Dorey
at 302-856-7303 (ph), 302-856-1845 (fax) or dorey@udel.edu.
University of Maryland Wye Field Day
August 16, 2001
U of MD Wye Research and Education Center
Queenstown, MD
Concurrent Tours 8:30-10:30 a.m.
1-Field Crops and Soils
·
Variable Rate Technology Advances in Production Agriculture
·
Hard (HRWW) and Soft Red Winter Wheat (SRWW) – Do they both
have a future in the Mid-Atlantic Region?
·
Irrigation Principles and Current Research
·
Key Aspects of Establishing a Riparian Buffer

2- Horticultural Crops
·
Containerized Nursey Crop Production/Nutrient Management
Facility
·
Environmental Modifications in Strawberries Using Local
Weather Forecasting Services
·
Double Crop Cut Flower Production
·
Strawberry Breeding Program

3-Animal Science
·
Determining the Role of Cattle in the Epidemiology of
Cryptosporidiosis
·
Breeding Highlights and Herd Tour
·
Grassland Management Can Benefit Birds of Prey

Gardening/Lawn Care 9:15 a.m.-12 noon
Seminar – “What does co-permitting mean to me” 10-11:30 a.m.
4-H Programs
·
Beef Cattle Judging
·
Natural Resources – Kid Style!
·
4-H Shooting Sports Trailer
Exhibits
Displays
BBQ 11:30-1:00 p.m.
Formal Garden Tour 1:15 p.m.
For More Information, contact Dr. Russel Brinsfield, 410-827-6202, or rb50@umail.umd.edu or http://www.agnr.umd.edu/maes/wrec/
Delmarva Breeder, Hatchery and Grow-out Conference
September 12, 2001
7 a.m. – 5 p.m.
Delmarva Conference Center, Delmar, MD
Sponsored by the University of Delaware and the University of Maryland in cooperation with the Delmarva Poultry Industry, Inc.
General session:
Grow-out
session:
Hatchery
session:
Aspergillus and mold
Cost: $40/person
Registration Deadline: August 24, 2001

Make checks payable to ‘Delmarva Poultry Industry, Inc.’ and mail to:
Bud Malone
University of Delaware
16483 County Seat Highway,
Georgetown, DE 19947
For More Information, contact Bud Malone, Extension Poultry Specialist at 302-856-7303 (ph), 302-856-1845 (fax) or email: malone@udel.edu.
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Weather Summary
Week of August 2
to August 8, 2001
|
|
Rainfall: None. |
|
Readings
taken for the previous 24 hours at 8 a.m. |
|
Air Temperature: |
|
Highs
Ranged from 94°F on August 8 to 83°F on August 4. |
|
Lows
Ranged from 75°F on August 8 to 58°F on August 2. |
|
Soil Temperature: |
|
81.4°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:
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.