Volume 8, Issue 24 September 1, 2000
Vegetables
Vegetable Insects - Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu
*** CORN
EARWORM ALERT***
Soybeans and Late planted vegetables – Since last Friday, we have experienced a major increase in
corn earworm MOTH FLIGHTS in a number of Kent County Blacklight Traps as well
as the Greenwood trap. The following are the nightly catches between Aug 28 and
Aug 30: Dover – 257, Frederica – 208, Greenwood – 48, Harrington – 118, Little
Creek – 25, Milford – 416, Rising Sun - 78, and Wyoming – 240. These catches
are as high or higher than catches in 1999 but the peak is occurring later.
THIS SHARP increase means that it will be critical to check double crop
soybeans and late planted vegetables carefully for earworms during the next 2 -
3 week period. Although we continue to observe earworms laying eggs in
soybeans, we have not yet seen a significant increase in larval populations.
The predicted warmer weather could result in quick egg hatch. Long term weather
forecasts have predicted a warmer and drier September. However, you should
still watch for diseased and parasitized worms as well as pod feeding before
making a treatment decision. The treatment threshold is 3 per 25 sweeps (narrow
rows), 5 per 25 sweeps (wide rows) or one per foot of row.
Peppers.
In areas where corn earworm catches are above 20 per night (all of Kent County, Greenwood and Seaford), sprays are needed on a 4-5 day schedule. In all other areas, sprays can be applied on a 5-7-day schedule.
Lima Beans.
With the significant increase in corn earworm moth flights, we are starting to see a significant increase in corn earworm egg laying, larval counts and pod damage. When possible, fields should be scouted twice a week to effectively time insecticide applications. Controls are needed if you find one larva per 6 foot of row. In many cases, multiple applications (2-4 sprays) may be needed to control newly hatched larvae. If you are using Lannate, the rate will depend on the larval size at the time of treatment. If worms are small, 1.5 to 2 pts. per acre will be adequate. However, if the worm size is mixed at the time of treatment, 3 pts./acre will be needed.
Snap Beans.
Corn borer and corn earworm moths can easily be found laying eggs in snap bean fields. Be sure to watch for corn borer larvae boring into the petioles and stems on small plants. If you notice an abundance of corn borer moths laying eggs in fields before the bud stage, be sure to check plants for flagged leaves and infested petioles. If ECB moth activity is abundant or catches are above 10 per night (Dover, Harrington, Milford, Frederica, and Wyoming), a spray will be needed before the bud spray to prevent larvae from tunneling into stems. Processing snap beans should be sprayed at the bud stage for corn borer control and at the pin stage for corn earworm and corn borer control. In the Dover, Frederica, Greenwood, Harrington, Little Creek, Milford, Rising Sun, and Wyoming areas, sprays are needed on a 3-day schedule from the pin stage until harvest. In all other areas, sprays are needed on a 4-day schedule from the pin spray until harvest.
Spinach.
Continue to watch for webworms and beet armyworm in spinach fields throughout the state. The first webworms have been detected on small plants. Spintor, Confirm, a Bt-insecticide, Ambush or Pounce can be used when spinach is less than 3 inches in diameter. Controls for webworms should be applied before significant webbing has occurred. If the beet armyworm is the predominant species, Spintor or Confirm should be used.
Sweet Corn.
All fresh market silking sweet corn should be sprayed on a 2-3 day for corn earworm, corn borer and fall armyworm control.
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Crop Profiles For Potatoes, Squash & Peaches
Posted for Comments – Susan
Whitney, Extension Specialist - Pesticides; swhitney@udel.edu
The Crop Profile for potatoes in Delaware has been posted on
the web at:
http://www.udel.edu/pesticide/potatoprofile.html
. USDA and EPA will be using this Crop Profile when making pesticide
registration decisions under FQPA. Comments on this document are
encouraged. Please send suggestions for revision to swhitney@udel.edu. If you would like
a hardcopy, please contact Whitney at 302-831-8886.
The Crop Profile for squash in Delaware has been posted on
the web at:
http://www.udel.edu/pesticide/squashprofile.html
. USDA and EPA will be using this Crop Profile when making pesticide
registration decisions
under FQPA. Comments on this document are encouraged. Please send
suggestions for revision to swhitney@udel.edu.
If you would like a hardcopy, please contact Whitney at 302-831-8886.
The Crop Profile for peaches in Delaware has been posted on
the web at:
http://www.udel.edu/pesticide/peach.html
. USDA and EPA will be using this Crop Profile when making pesticide
registration decisions under FQPA. Comments on this document are
encouraged. Please send suggestions for revision to swhitney@udel.edu. If you would like
a hardcopy, please contact Whitney at 302-831-8886.
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Vegetable Diseases - Bob Mulrooney, Extension Vegetable Pathologist, University of Delaware; bobmul@udel.edu
Downy mildew continues to be found in cucurbit and lima bean fields. Continue to scout fields regularly. See Issues 23 & 21 of Weekly Crop Update
for further information about this disease.
White mold is still being found in lima bean fields. Continue to scout fields regularly. Refer to Issues 22 & 20 of Weekly Crop
Update for more information about this disease in lima beans.
Field Crops.- Bob Mulrooney, Extension Vegetable Pathologist, University of Delaware; bobmul@udel.edu
Soybeans. White mold caused by Sclerotinia sclerotiorum has been
diagnosed in soybeans this week. The first symptoms that are often seen are
scattered pockets of plants with dead tops or plants in low areas with dead
tops. Leaves often have a gray-green appearance before turning brown. Leaves
often stay attached to the stems. Infection often occurs at the stem nodes and
the stem lesions often girdle the plant and stop the flow of water and
nutrients. Cottony mycelium (fungus threads) is often seen on infected plant
parts. The best diagnostic feature is the presence of the hard, black round to
irregularly shaped sclerotia (hard overwintering structures of the fungus) that
look like rat droppings. These are often found on the stems or hidden in the
white cottony fungus growth. Often the sclerotia can also be found in the stem
pith, if the stems are split open. Seed can often be contaminated with
sclerotia during harvest and can increase seed decay during storage if moisture
is present. Sclerotia are also spread within the field and from field to field
during combining. Peas, lima beans, and snap beans are all hosts to this
fungus. This disease has certainly been favored by the cooler than normal
temperatures and abundant rainfall. Try to break the cropping sequence and
avoid planting these susceptible crops if possible. Deep plowing before
planting can bury sclerotia to prevent spore production during the summer.
Flowering of soybeans during periods of cool temperatures and plenty of
moisture favors infection. Unfortunately most of the agronomic practices that
favor rapid canopy closure which helps to optimize yields and provide good weed
control favor white mold development. On the plus side, white mold is only a
problem during these unusually cool, wet seasons.
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 Phil Shields at (410) 742-8788 or e-mail: ps136@umail.umd.edu
|
Location |
8/23 |
8/24 |
8/25 |
8/26 |
8/27 |
8/28 |
8/29 |
8/30 |
|
Bridgeville, DE |
1 |
2 |
4 |
3 |
3 |
4 |
0 |
0 |
|
Laurel, DE (Collins Farms) |
1 |
4 |
3 |
3 |
4 |
6 |
1 |
0 |
|
Galestown, MD |
0 |
3 |
4 |
2 |
3 |
6 |
0 |
1 |
|
Georgetown, DE |
1 |
2 |
2 |
2 |
2 |
3 |
1 |
0 |
|
Hebron, MD |
0 |
4 |
4 |
4 |
3 |
6 |
2 |
1 |
|
Salisbury, MD |
|
1 |
2 |
4 |
1 |
3 |
2 |
1 |
|
Vienna, MD |
0 |
3 |
3 |
2 |
3 |
5 |
0 |
0 |
|
Laurel, DE (Vincent Farms) |
1 |
4 |
3 |
4 |
4 |
6 |
1 |
1 |
The first fungicide spray should be applied when the watermelon vines meet within the row. Additional sprays
should be applied using MELCAST. Accumulate EFI (environmental favorability index) values beginning the
day after your first fungicide spray. Apply a fungicide spray when 30 EFI values have 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 0 and start over. The first and last day listed above can be partial days so use the larger EFI value
of this report and other reports for any specific day.
If, for some reason, a serious disease outbreak occurs in your field, return to a weekly spray schedule.
More detailed information concerning MELCAST and sample data sheets are available on the web at http://www.agnr.umd.edu/users/vegdisease/vegdisease.htm or http://www.udel.edu/IPM/ v
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Field Crops
Field Crop Insects - Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu
*** CORN
EARWORM ALERT***
Soybeans and Late planted vegetables – Since last Friday, we have experienced a major increase in
corn earworm MOTH FLIGHTS in a number of Kent County Blacklight Traps as well
as the Greenwood trap. The following are the nightly catches between Aug 28 and
Aug 30: Dover – 257, Frederica – 208, Greenwood – 48, Harrington – 118, Little
Creek – 25, Milford – 416, Rising Sun - 78, and Wyoming – 240. These catches
are as high or higher than catches in 1999 but the peak is occurring later.
THIS SHARP increase means that it will be critical to check double crop
soybeans and late planted vegetables carefully for earworms during the next 2 -
3 week period. Although we continue to observe earworms laying eggs in
soybeans, we have not yet seen a significant increase in larval populations.
The predicted warmer weather could result in quick egg hatch. Long term weather
forecasts have predicted a warmer and drier September. However, you should
still watch for diseased and parasitized worms as well as pod feeding before
making a treatment decision. The treatment threshold is 3 per 25 sweeps (narrow
rows), 5 per 25 sweeps (wide rows) or one per foot of row.
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Attention All
Kent County Farm Operators Pre-Harvest Planning Workshops - Gordon Johnson, Extension Agriculture Agent, Kent County, gcjohn@udel.edu
Sponsored
by the Farm Service Agency and University of Delaware Cooperative Extension
Office in Kent County
Topics Will Include:
Making the Best Use of Farm Programs in
Marketing
Review of the LDP program and
new eligibilities.
Marketing
Assistance Loans
Payment
limitations review
Loan repayments with Commodity
Certificates
Farm
Storage Facility Loans
Review of other available farm programs
Temporary grain storage and handling
Marketing strategies for harvest and the
coming year
You are welcome to attend this workshop in
one of 3 locations and times:
Workshop 1
Date: Wednesday, September 6, 2000
Time: 7-9 PM
Place: Lake Forest High School Vocational
Agriculture Classroom
Workshop 2
Date: Monday, September 11, 2000
Time: 8-10 AM
Place: UD Kent County
Extension Office, Rt. 113, Dover, next to DelDOT
Workshop 3
Date: Wednesday,
September 13, 2000
Time: 7-9 PM
Place: Snow Farms
Meeting Place, Whitehall
Crossroads, North of Leipsic
All Kent County grain producers and farm operators are encouraged to attend one of three pre-harvest workshops sponsored by the Farm Service Agency and UD Cooperative Extension Office in Kent County.
Personnel from the Farm Service Agency will be on hand to review LDP’s, marketing assistance loans, commodity certificates, and farm storage facility loans. Participants will work through examples involving LDP’s, payment limitations, storage, loans, and certificate use. The session will then be opened up to questions. Other farm programs will also be reviewed.
Extension personnel from UD will be on hand to talk about temporary grain storage and handling, provide designs, and discuss critical considerations for temporary storage. The UD Extension Marketing specialist will provide information on marketing considerations for the harvest season and the coming year.
Call the Extension Office at (302) 697-4000 or the FSA Office at (302) 697-2600 x 2 if you are planning to attend one of these sessions. Anyone interested is welcome to attend. For further information or special consideration in accessing these workshops contact Gordon Johnson at 697-4000 or Greg Hudson at 697-2600 in advance.
See you there.
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Blank Corn Ear Tips - Richard W. Taylor, Extension Agronomist; rtaylor@udel.edu
Incomplete kernel set can be caused by numerous factors most of which relate to water and drought conditions (See photo below, courtesy of Ted Haas and Eddie Johnson, University of Maryland). Drought can cause delayed silk emergence. Since silks emerge from the base of the ear out to the ear tip in a sequential pattern, delayed emergence can mean that the ear tip silks emerge after pollen shed is completed. Incomplete kernel set also can be caused by insect (Japanese beetles and Western and Northern corn rootworm beetles) feeding on silks and interfering with pollen fertilization of the ovules (potential kernel).
What’s causing poor tip fill this year when for the most part drought has not been a problem? One possible answer is that the unusually favorable conditions prior to pollination when kernel number and row number are determined allowed an unusually high number of potential kernels per row. According to Dr. Bob Nielsen, longer than normal potential ears often fail to silk completely before the pollen source runs out. The typical harvested ear size is 16 to 18 rows by 30 to 40 kernels long. Many ears this year show fifty or more potential kernels per ear.
One reason for incomplete kernel set could be the interaction of genetics (for specific hybrids) and the unusual growing environment they experienced this year. I also believe that this problem occurred because we have had inadequate sunlight to maximize yield potential so many of the potential kernels were aborted by the plant when the plant could not produce enough sugars to fill the potential kernels. Most of the state has experienced many more days of cloudy weather than is typical during the growing season. Another factor is that corn has not been without stress this year. The stresses range from too much water to too little available nutrients due to excessive leaching from all the rain.
Lastly, my thanks to Ted Haas and Eddie Johnson from the University of Maryland and Dr. R. L. Nielsen at Purdue University for their comments which are incorporated in this article.

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Grain Marketing Highlights - Carl
German, Extension Crops Marketing Specialist; clgerman@udel.edu
This past week has seen a marked improvement in new crop corn, soybean, and wheat prices. The recovery is due to three primary reasons: first, the European Union announced a curtailing of wheat exports due to possible crop production reductions in the coming year, further U.S. weekly crop rating condition reports have declined slightly over the past two weeks. The third and perhaps the most important reason, which relates directly to crop condition ratings, is the 'heat' that entered the corn belt which is rapidly maturing and drying the corn and soybean crop in large portions of the midsection of the corn belt. Commodity prices for corn and soybeans at the CBT currently remain under the loan rate at at $1.94 per bushel for corn and $4.99 per bushel for soybeans.
Farm Marketing Strategy
We are entering a period in the marketing year that makes general information more difficult to base marketing decisions on. From here on out, most marketing decisions become an individual consideration, based upon individual options. Some of the decision making process depends on the alternatives individuals have for storing grain. To a lesser extent, as of this writing, is the concern of exceeding the payment limit for the loan deficiency program. Soybean prices, for example, are currently within 37 cents per bushel of the $5.36 local loan rate. The corn loan rate is $2.10 per bushel. For those who have chosen to keep most of their new crop soybeans and 40 to 50 percent of their new dry land corn crop unpriced up to this point in time, there is still no need to be in a hurry for making additional sales. The reason for this is by making sales below the loan rate, even if you think prices will drop during harvest pressure, the potential of forward selling for a cheap price and not getting a loan deficiency payment is there. For example, if one were to forward price soybeans for $4.69 per bushel now and ends up harvesting the beans at a harvest time cash price of $5.36 per bushel, taking the forward contract price now results in achieving a lower per bushel sales price on the contracted bushels due to the deficiency payment being eliminated. In other words, for those who have waited to advance new crop sales up to this point in time why sell now?
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Corn Stalk Rots and Root Rots – Derby Walker, Extension Agricultural Agent, Sussex County, derby@udel.edu
With the current weather we are experiencing, root and stalk rots may appear in field corn. To test for root rots, check the quality of the root system by pulling up some corn plants. Areas to check first would be where the corn "dried down " first. A very rapid dry down may have been unnatural, due to a weakened or dead root system. If plants pull up easily and only have a small root system, these plants may root lodge. It is very difficult to harvest root lodge plants because they either pull out of the ground and plug the header of the combine or are easily pushed over by wind.
To test for stalk rot, try crushing the stalk. If the stalk crushes easily, there is a stalk quality problem. If stalk rot or root rot are present, you will need to harvest the corn early to avoid severe yield losses. Wet weather and wind will cause lodging problems. Growers in 1999 lost up to 40 bushels per acre because of red root rot and stalk rots. Corn varieties vary in their resistance to root rot and stalk rot. Now is the time to make notes on which varieties had problems and which ones held up. These notes will aid you in your selections of corn hybrids for next year.
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Upcoming Events…
Date: September
5 & 6
Training: 8:15 a.m. to 4:00 p.m. DAY 1
8:15 a.m. – Noon DAY 2
Exam: 1:00 p.m. DAY 2
Location: Training for both dates will be held at the University of
Delaware Kent County Cooperative Extension Office
For More Information:
Contact Susan Whitney at 302-831-8886 or swhitney@udel.edu.
Success
with Small Grains Workshop
We
will go through critical decisions with small grain production during the year
from start to finish.
Date: Thursday, September 7, 2000
Time: 6:30-9:00 PM
Place: University of Delaware Extension Office, Rt. 113, Dover, Next to
DelDOT
Dinner: A light dinner will be provided
For More Information: Contact Gordon Johnson at
302-697-4000 or gcjohn@udel.edu
You are welcome to attend
this workshop in one of 3 locations and times:
Workshop 1
Date:
Wednesday, September 6, 2000
Workshop 2
Date: Monday, September 11, 2000
Workshop 3
Date: Wednesday, September 13, 2000
For Further Information: contact Gordon Johnson at
697-4000 or Greg Hudson at 697-2600 in advance
University of Delaware Corn
Hybrid Field Day
Date: Tuesday, September 12, 2000
Time: 9:00 AM - 1:00 PM
Place: Corn research plots on Scuse Farms, Smyrna-Leipsic Rd near the
crossing with Hurd Road.
Cooperator: Mike Scuse
Lunch: A lunch of hotdogs and hamburgers will be provided
For More Information: Contact Gordon Johnson at
302-697-4000 or gcjohn@udel.edu
Date: September 21, 2000
Time: 4:30 p.m. Plots available for viewing
5:30 p.m. Comments from the
Pumpkin Team
Location: University of Maryland’s
Wye Research & Education Center, Queenstown, Maryland
For More Information: Contact Bob Rouse at 410-827-8056 or rr36@umail.umd.edu
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Week of August 24 to August 30 |
|
Rainfall: |
|
0.32 on August 24 0.01 on August 25 0.05 on August 28 0.09 on August 29 0.15 on August 30 |
|
Readings taken for the previous 24 hours at 8 a.m. |
|
Air Temperature: |
|
Highs Ranged from 83°F on August 26 to 80° F on August 28 & 30. |
|
Lows Ranged from 71°F on August 29 &30 to 57° F on August 26. |
|
Soil Temperature: |
|
76°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.