Volume 12, Issue 1
March 12, 2003
The Weekly Schedule Begins –
This
newsletter is designed to provide subscribers with the latest information on
disease and insect problems, weed control information, crop progress reports,
and other timely topics related to agronomic and vegetable crop production in
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Email Address Changes
Please
forward email address changes. If your
email address has changed in the last 6 months, please forward the new address
to me at wootten@udel.edu. Thanks!

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Avian Influenza Update –
Field
application of poultry litter and complete cleanouts allowed March 11
Today, Michael Scuse, Delaware Secretary of Agriculture, lifted restrictions
on the spreading of poultry litter, and on the complete cleanouts of poultry
houses in
The rescission of regulation 1.0, which refers to the movement, transportation,
or field application of poultry litter, and regulation 2.0, which refers to
poultry house cleanouts, means normal poultry litter removal, storage, and
land application using a nutrient management plan can occur beginning 12:00 AM,
March 11, 2004. The regulations being rescinded were adopted on an
emergency basis on
The rescission is being ordered in cooperation with the Maryland Department of
Agriculture, the Virginia Department of Agriculture and Consumer Services, the
Delmarva Poultry Industry, Inc., and the Delmarva Poultry Industry Emergency
Disease Task Force.
The regulation concerning the transportation of live poultry intrastate or in
or out of
Secretary Scuse said, “Rescinding these regulations is not a call for ‘business
as usual’. The recent and unfortunate avian influenza cases will forever be a
wakeup call for Delmarva’s poultry industry, all poultry industry personnel and
suppliers, and all poultry growers, whether they are commercial growers, back
yard growers, or hobbyists. We must be more vigilant and more careful in
practicing good biosecurity to protect our poultry flocks. I encourage
producers and everyone traveling in the area south of U.S. Rt. 50 to practice
the same strict biosecurity precautions that we have had in effect since
February 6. We don't want to re-infect Delaware flocks nor create more problems
for our neighboring states that have cooperated with us in every way as we have
fought to contain and eradicate avian influenza in Delaware.”
“In addition, I want to thank the agri-business community for their cooperation
in canceling auctions and meetings in the past 5 weeks. At this time, auctions
and meetings not involving live birds can resume. Any person associated
with the poultry industry who must attend these auctions and meetings should
practice strict biosecurity and change clothing and shoes worn in poultry
operations before participating.”

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Vegetables
Vegetable Insects -
Seed Corn Maggot (SCM)
in Spring Planted Vegetables.
Although
soil conditions are drier and warmer compared to this same time last year, seed
corn maggot can still be a potential problem in all early planted fields. Seed
corn maggot flies lay eggs in recently plowed and/or manured
fields. Cool wet conditions at planting, the use of manure and/or plowing under
of green cover crops close to planting all favor maggot problems.
(a) Peas and Beans: In recent years,
the use of a hopper box treatment of diazinon 50W has provided excellent SCM
control in peas and early planted beans. At the present time, this is the only
diazinon formulation registered for use on peas and snap beans. It should be
applied at a rate of ½ oz per bushel of seed and graphite added to prevent
bridging in the planter. Unfortunately, we will only have this product
available until July 2004 or at the latest November 2005. Lorsban-SL, only
available as a commercial seed applied treatment, has also provided very good
control. Cruiser 5F (thiamethoxam),
another seed applied material, was labeled in the fall of 2003. It is labeled
for succulent shelled and edible podded beans including lima beans, blackeyed
peas, cowpeas, southern peas, snap beans, and wax beans. The label states early
season seed corn maggot protection at a rate of 0.765 – 1.28 fl oz/100 lbs. of
seed. It is also highly recommended that Cruiser be used with compatible and
registered seed treatment fungicides.
(b) Spinach: The only available SCM control option is a
broadcast application of 2- 3 qts/A of diazinon AG500 applied right before
planting and immediately incorporated 2-3 inches deep. In order to achieve
effective control, diazinon should not be incorporated too deeply and the
ground should only be worked once after application.
(c) Sweet Corn: In addition to the
permethrin (Kernel Guard Supreme and KickStart VP) and the diazinon/lindane(Kernel
Guard, Agrox Premiere and KickStart) hopper box treatments, we now have two new
hopper box treatments available in 2004: Concur
and Latitude. These hopper box treatments should be applied at a rate of
1.5 oz/42 lbs of seed. The insecticide component in both products is
imidacloprid (same active ingredient as Gaucho). In addition to hopper box
treatments, a number of seed applied treatments including Lorsban SL, Gaucho,
Poncho and Cruiser are available for sweet corn. Soil insecticides including
Force, Lorsban, Fortress, Furadan and Counter are also labeled for SCM control
in sweet corn.
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Back to Basics:Vegetable Crop Fertility I – Ed Kee, Extension Vegetable Crops Specialist; kee@udel.edu
Vegetable
crop fertilization questions seem to be springing up more frequently than in
recent years. I think this is a result
of higher fertilizer prices, new fertilizer products, and a new generation of
farm decision-makers who are facing these choices for the first time. Therefore, I will be addressing these
questions weekly, as well as other timely topics related to general vegetable
production.
Understanding
the acidity of the soil and how liming soils works is the foundation of any
soil fertility program. Many farmers and
others remember Leo Cotnoir, long-time soil fertility specialist with the
The
two main reasons for liming soils are to make soil plant nutrients available
and to prevent aluminum toxicity due to soil acidity. There you have it. A pH test measures the relative acidity or
alkalinity of the soil. On the scale,
seven is neutral; less than seven is acid, greater then seven is basic. In the humid regions with abundant rainfall,
our soils have a natural tendency to be acid.
Maintaining the soil pH at a level between 6.0 and 6.5 on most of our
soils does allow soil plant nutrients to be more abundant in forms that are
absorbed by plants and does reduce aluminum levels to non-toxic amounts
available to plants.
The
major implication here is that if the soil reaction as measured by soil pH is
between 6 and 6.5, more efficient use of fertilizers, manures, and green
manures is obtained. This is expressed
as better crop yield potential and real savings in fertilizer dollars. The lime requirement of a soil depends on
total acidity that must be neutralized to raise pH to the desired level. Most vegetable crops have a target pH of 6.2
or 6.5; only sweet potatoes or scab-susceptible white potato varieties have a
target pH of 5.2. In those cases, the
plant pathogens that cause diseases do not thrive in a low pH environment.
In
addition, lime is the cheapest and most readily available supply of calcium, a
plant nutrient critical for yield and quality for many vegetable crops. Calcium is a major component in the structure
of cells, including cells in the harvested fruit of many vegetable crops, such
as cantaloupes, watermelons, cole crops, cucumbers, and many more. Calcium is considered to be largely immobile
within the plant. That is, it does not
move from one part of a plant to another, but rather is taken up by the roots
and distributed to the developing tissues.
Having adequate amounts of soil calcium readily available is critical
for not only good yields, but good quality as well.
Soil
pH and soil calcium, as determined by soil test are only roughly related. In all cases, calcium increases as soil pH
increases. The amount of soil calcium at
a particular soil pH level, is a function of soil properties, especially soil
texture and cation exchange capacity.
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Vegetable Diseases -
Stewart’s
Wilt of Sweet Corn.
Stewart’s Wilt is still one of the most
important diseases of sweet corn on Delmarva. Control of this bacteria (Erwinia stewarti) is based on control of
the corn flea beetle which vectors this bacteria to corn and causes wilt on
susceptible hybrids. Planting resistant fresh market and processing hybrids is
the best control strategy. If susceptible hybrids are grown, control of flea
beetles is extremely important. The Winter Temperature Index is helpful
determining the risk of Stewart’s wilt based on flea beetle survival. As you
can see from the table, most years here are very favorable for flea beetles
surviving overwinter. Predicting severity of Stewart’s wilt based on predicting
populations of beetles carrying the bacteria in reality is very difficult.
However, the last several years have not been favorable for Stewart’s wilt and
it has not been much of a problem here. Sweet corn growers can protect
susceptible and moderately susceptible hybrids by using soil insecticides or
commercially applied seed treatments. Counter and Furadan are the only soil
insecticides labeled for sweet corn that provide effective flea beetle control.
The commercial applied seed treatments, Gaucho, Poncho and Cruiser, will also
provide flea beetle control. Recent
research in
Winter Temperature
Index For Predicting Stewart’s
Wilt in
Average monthly
temperatures in oF at
|
|
2003- 04 |
2002-03 |
2001- 02 |
2000-01 |
1999-00 |
1998-99 |
1997-98 |
1996-97 |
1995-96 |
1994-95 |
|
December |
38.6 |
36.7 |
43.2 |
31.2 |
40.3 |
41.3 |
39.3 |
42.0 |
33.5 |
43.0 |
|
January |
29.5 |
28.9 |
40.0 |
33.8 |
33.9 |
39.5 |
42.6 |
35.0 |
33.5 |
39.0 |
|
February |
35.2 |
33.8 |
39.9 |
38.8 |
39.7 |
38.7 |
40.6 |
41.5 |
34.7 |
33.8 |
|
INDEX |
103.3 |
99.4 |
123.1 |
103.8 |
113.9 |
119.5 |
122.5 |
118.5 |
101.7 |
115.8 |
Average monthly
tempertures in oF at
|
|
2003- 04 |
2002-03 |
2001- 02 |
2000-01 |
1999-00 |
1998-99 |
1997-98 |
1996-97 |
1995-96 |
1994-95 |
|
December |
34.0 |
33.5 |
43.3 |
31.1 |
39.1 |
41.0 |
38.4 |
40.9 |
32.1 |
41.8 |
|
January |
26.4 |
27.1 |
39.6 |
31.5 |
32.6 |
34.8 |
40.9 |
33.2 |
30.9 |
37.6 |
|
February |
33.1 |
29.5 |
40.1 |
38.4 |
37.8 |
38.0 |
40.6 |
40.3 |
34.7 |
31.7 |
|
INDEX |
93.5 |
90.1 |
123.0 |
101.0 |
109.5 |
113.8 |
119.9 |
114.2 |
97.7 |
111.1 |
Severity
Index: < 90, usually
absent; 90-100, intermediate; >100, usually
severe.
Used
to predict overwintering flea beetle populations that vector Stewart’s wilt.
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Vegetable Diseases -
Potatoes.
Just
a reminder, as growers begin to treat seed potatoes for planting, that late
blight was not a big problem in seed areas last year, but there was some
around. Hopefully, your seed is free from late blight, but there is more reason
this year to use a seed treater with mancozeb or maneb for late blight control.
These include the combination seed treaters Maxim MZ, Tops MZ and Tops MZ
Gaucho, Evolve, MonCoat MZ, and the mancozeb alone products including Polyram.
Note: For a great
article on physiological aging of seed potatoes, check out the article written
by Alexander Pavlista, Extension Potato Specialist in
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Vegetable Diseases – Kate
Everts,
Fungicide Update.
Recently
several new fungicides have been registered for use on vegetables. In addition,
some formulation changes have occurred since the 2003 field season. The following is a short, non-comprehensive
list of some of the changes:
Endura 70 WG is labeled on
beans, bulb vegetables, carrots, peppers, eggplant, potatoes, tomatoes, and
onions. It has activity against white
mold, Botrytis diseases, rust, Purple blotch on onion, and Alternaria diseases
such as early blight. In our 2003 trial
on lima bean in
Pristine 38 WG is labeled for
use on bulb vegetables, carrots and cucurbits.
It has activity against Alternaria, anthracnose, Cercospora, gummy stem
blight (GSB), downy and powdery mildew.
In our trial in 2003, Pristine used in alternation with Bravo did not
provide superior control to Bravo used alone.
Trials in
Amistar 80 WP has the same
active ingredient, and is a formulation change of, Quadris. It is labeled on the same crops. Expect it to be effective on the same
diseases that Quadris managed.
Tanos 50 WDG is labeled on
lettuce, peppers, tomatoes, potatoes and cucurbits. Tanos has activity against Alternaria
diseases, anthracnose, and downy mildew.
Tanos is not registered for gummy stem blight (GSB) management, although
in our trial it had some efficacy on GSB.
In other words, don’t use it for GSB, however if you are using it for
anthracnose or Alternaria, there should be some suppression of GSB. Tanos also has activity against Phytophthora
diseases: late blight, Phytophthora blight of peppers (foliar and fruit phase,
only), and buckeye rot (suppression only).
For
more specific information on rates and efficacy, see The Commercial
Vegetable Production Recommendations and the individual fungicide
labels.
Resistance
management guidelines have also changed.
We now recommend that QoI class fungicides (Quadris, Amistar, Cabrio,
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Field Crop Insects - Joanne
Whalen, Extension IPM Specialist;
jwhalen@udel.edu
Field Corn Soil
Insect Management.
In addition to the diazinon-lindane and permethrin hopper box
treatments, two new hopperbox insecticide seed treatments are now labeled for
field corn. They are Concur and Latitude. Both contain imidacloprid (the same
material in Gaucho and Prescribe) and are labeled at a use rate of 1.5 oz/42
lbs of seed. In addition, Poncho and Cruiser, commercial seed applied
treatments are also available for field corn. It is my understanding that
Gaucho and Prescribe will not be offered in 2004, except on pre-existing seed
stocks. In addition, we now have a number of pyrethroids labeled for in-furrow
use. The following is a brief summary of
available materials and insects appearing on the label:
I. Corn Rootworm
(Larval Control) - In addition to soil insecticides and Bt rootworm technology,
the following commercial seed applied treatments are labeled for control of rootworm
larvae:
(a) Cruiser 5FS
(thiamethoxam): Commercially applied to corn seed at 5.1 to 9.0 fl oz / 100
lbs of seed. The label states corn rootworm protection only for light to
moderate infestations. Do not apply less than 1.125 mg / kernel and do not exceed
1.4 mg / kernel.
(b)
Poncho 1250 (clothianidin): Commercially applied to corn seed at 1.25 mg
ai/seed.
II.
Wireworms: High soil organic
matter, sod covers, and heavy grass weed pressure the previous season all favor
wireworm populations. Fields having a combination of high organic matter and
heavy grass weed pressure are the most susceptible to damage. Wireworm larvae
spend multiple years in the larval stage and the larvae move up and down in the
soil profile following moisture gradients. Therefore, good control is often
difficult to achieve. Soil insecticides including Regent, Force, Fortress, Furadan, Lorsban and Counter are
labeled for wireworm control. All materials must be placed in-furrow to get
effective control and applied at the higher end of the labeled rate. In furrow
applications of Warrior and Baythroid are also labeled for wireworm control.
The use of a hopper box seed treatment that includes imidacloprid, lindane
or permethrin will provide protection against seed injury by wireworms.
Commercially applied seed treatments including Cruiser (thiamethoxam)
and Poncho (clothianidin) have provided good wireworm control. NOTE
– Labels state seed and seedling protection.
III. Grubs: In
general, grubs are favored by a number of factors including planting into
double crop soybean stubble, old sod, hay, pasture or
set-aside acreage. The most accurate way to measure the potential for a grub
problem is to sample fields for grubs before planting, but it should be done
before a field is tilled. The most accurate results will be obtained when the
soil temperatures at 6-inches deep are at least 45 degrees F. At each site,
sample one square foot of soil dug six inches deep. One to two samples should
be taken for every 10 acres with no less than 10 samples per field. A treatment
is recommended if you find 1-2 grubs per foot in heavy soils or 0.5 – 1 grubs
per foot in sandy soils. Soil insecticides need to be placed in-furrow to get
effective grub control. Counter, Force, Fortress and Regent are labeled for
grub control. In furrow applications of reduced rates of Baythroid and Warrior
only provide grub suppression. (Remember, at planting insecticides are only designed to provide
control of grubs present at planting time. You should not expect control of
larvae present in August and September that resulted from eggs laid in early
July). In addition to the standard soil insecticides, the hopper
box seed treatments Concur and Latitude are labeled against white grubs and the
commercially applied seed treatments including Cruiser (thiamethoxam)
and Poncho (clothianidin) are also labeled against white grubs. NOTE
– Labels state seed and seedling protection.
IV. Seedcorn
Maggots: Cool
wet conditions at planting, the use of manure and/or plowing under of green
cover crops close to planting all favor maggot problems. Depending on spring
weather conditions, most early planted conventional corn and all no-till
plantings will be susceptible to seed corn maggot attack. In addition to soil
insecticides and in-furrow pyrethroids, seed treatments have provided effective
control. Hopper-box treatments containing diazinon,
imidacloprid or permethrin as well as seed
commercially treated with clothianidin (Poncho) or thiamethoxam (Cruiser) will provide seed corn maggot control.
V.
Black Cutworm.
This insect is
favored by late planting, broadleaf weed growth (especially chickweed) present
before planting, poorly drained field conditions and reduced tillage. Rescue
treatments can be applied for this soil insect if you are able to scout fields
twice a week once leaf feeding is detected. If you are unable to scout and you
have conditions favoring cutworms, a pyrethroid
(Ambush, Asana, Pounce, Mustang or Warrior) or Lorsban tank mixed with an herbicide and applied close to planting has provided
effective control. Asana, Mustang and Warrior are also labeled as a liquid
t-band application at planting for cutworm control. The granular insecticides
Force, Lorsban and Fortress are labeled for cutworm
control, but must be applied as a T-band to be effective. Pheromone traps
placed in the field by mid-March can be used to determine when to look for cut
plants as well as areas of the state most likely to experience economic levels.
Look for pheromone trap counts in future reports.
The seed
treatments, Cruiser and Poncho, also list cutworm on the labels. Since these
products are systemic, larvae must feed to be affected. The Cruiser label only
states cutworm suppression, not control. The Poncho 250 label states that
larvae up to ½ inch long are affected. The Poncho 1250 label states that larvae
up to 1-inch long are affected. In the Delaware/Maryland area, we are mainly
dealing with populations that lay eggs early on weeds or in some cases an
overwintering populations so we generally find larger larvae (1/2 inch and
greater) present in fields at planting time.
Therefore, we feel that Poncho 250 will probably not provide economic
cutworm control. Poncho 1250 may provide better control; however, fields should
still need to be scouted carefully.
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Small Grain Weed Control -
Ryegrass control is limited to Hoelon this time of
year. There are areas of
Hoelon-resistant ryegrass, and these biotypes will not be controlled with
Hoelon. Hoelon should be applied to
ryegrass before it is 5 inches tall or more than 2 tillers.
It is time to consider your weed control for the
small grain crop. Fields that were
no-tilled or chickweed emerged shortly after planting in the fall are fields to
check first for spring treatment. If you
have wild garlic or Canada thistle the time of application should be delayed
since you need to spray these weeds when they have fully emerged. Coverage is important for these species. If weed pressure from winter annuals is
great, it may not be possible to get control of the winter annuals and
perennials with one application. In that
case, two applications maybe required.
You can mix your Harmony Extra with nitrogen. If spraying Harmony Extra with nitrogen be
sure to pre-mix it in water first. If
using nitrogen as your carrier, no need for a surfactant unless wild garlic is
over 8 inches tall. Applying Harmony
Extra in nitrogen diluted with water, use a non-ionic surfactant at ½ to 1
pint/100 gallons of solution. If
applying it in water, use non-ionic surfactant at 1 qt/100 gallons.
Have you considered resistance management with your
small grains? Most of the small grains
get treated only with Harmony Extra, which contains two ALS-inhibiting
herbicides (some type of herbicides as Pursuit, Accent, Classic, etc). Many weeds have developed resistance to
herbicides that have this mode of action.
Consider how often a field is planted to small grains and how often it
gets treated with Harmony Extra. If this
rotation is short, 3 years or less, consider tankmixing another herbicide with
Harmony Extra to minimize the risk of developing herbicide resistant weeds.
Finally, the following are the timing limitations
for small grain herbicides. The timing
restrictions are based on crop safety.
2,4-D - up to jointing stage (pre-jointing)
Banvel/Clarity - up to jointing stage
(pre-jointing)
Buctril - up to boot stage
Harmony Extra or Harmony GT - up to flag stage
(pre-flag leaf)
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Control the Horseweed (or marestail)
in No-Till Soybeans When it’s Small -
The presence of glyphosate-resistant horseweed has
made no-till soybean burndown programs more challenging. (Glyphosate is the active ingredient in
Roundup and Touchdown). This species is
not a problem in tilled fields (because it emerges before the tillage is completed,
so tillage kills it) or in corn (because atrazine is pretty effective on
it). Rather the problem has only been
showing up in no-till soybean fields where glyphosate alone has been used for
burndown control prior to planting. The
presence of glyphosate-resistant horseweed is so wide-spread and it moves so
easily with the wind, you have to assume that the horseweed plants in your
field are resistant and not rely on glyphosate to control them.
What to use??
A program based on a plant-growth regulator herbicides (2,4-D or
dicamba). Glyphosate will not kill the
resistant biotypes. Paraquat often will
not effectively control all the plants, and it often requires two applications
for good control (and two applications is not a sound resistance-management
strategy). There is concern about
excessive use of ALS-inhibiting herbicides such as Amplify, FirstRate, Canopy,
or Canopy XL that could lead to additional resistance. That leaves 2,4-D or dicamba. Dicamba is the active ingredient in Banvel
and Clarity. The pint rate of 2,4-D
ester is only marginal on horseweed (particularly when the plants are 4 inches
or taller). A quart rate of 2,4-D ester
is needed to consistently control this species.
For most formulations, a quart rate (assuming 4 lb ai/gallon
formulation) requires a period of 30 days from time of application until
soybeans can be planted. There are a few
formulations available that require only 15 days between application and
planting soybeans. So, this treatment
should be made as early as possible due to controlling small weeds and allowing
the time interval prior to planting.
There are some differences between Banvel and Clarity labels. Banvel is labeled for 8 to 16 oz/A and
requires a 30-day interval between application and planting soybeans. Clarity use rates are 4 to 16 oz/A. The interval between Clarity application and
soybean planting is defined by a total accumulation of 1 inch of rain followed
by 14 days. Averaged over the past 20
year weather records, this is a 26 day period, but it can be longer.
There are a number of weed species not controlled
by 2,4-D or dicamba. These products
should be tankmixed with a non-selective herbicide such as paraquat or
glyphosate. (Paraquat is the active
ingredient in Gramoxone Max and formulations are available). Since most of the no-till soybeans will be
planted with Roundup Ready soybeans, paraquat would be a better choice from a
resistance management standpoint.
Additional flush of weeds is possible with this
early application, so a tankmixture with a residual herbicide (such as
Boundary, Sencor, Valor) may eliminate the need for an application of paraquat
at planting.
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New Weed Control Guides For Corn and
Soybeans Available - Free -
Available
from your county extension office are two weed management guides for assistance
in weed control in corn and soybeans. The
first half of each guide deals with soil-applied herbicides and the second half
is for postemergence herbicides. These
guides have pre-mixes and what is in the pre-mix, expanded weed control tables,
information on application timing, comments for each of the herbicides, and
much more. Contact your county extension
office or visit http://www.rec.udel.edu/weed_sci/WeedPublicat.htm for these free guides.
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Grain Marketing Highlights - Carl German, Extension Crops Marketing Specialist; clgerman@udel.edu
Soybean Analysis.
Price bidding in
the soybean market is continuing in a volatile fashion with some evidence of
old crop supply rationing taking place. Cancellations of old crop soybean
sales, already on the books, are becoming more of a factor each week, with net
export sales for old crop soybeans resulting in a reduction in those sales
again this week. New crop export bookings were up 4 percent from the previous
week, but down 6 percent from the 4-week average. The strength in soybean
prices this week is due primarily to the interest in new crop soybeans, due to
the anticipated reduction in Southern Hemisphere production.
According to one
long time market observer, "Anyone that has any remaining old crop
soybeans should go ahead and price them, making sure that any beans (tested for
germination) needed for planting should be kept back, because it is going to be
that tight."
Corn Analysis.
The
Wheat Analysis.
New crop July '04
wheat futures are currently bidding at $3.79 per bushel. The life of contract
high for new crop wheat futures was set at $4.02 per bushel in early January.
In mid-February, Jul '04 wheat futures were bid to the $4.00 per bushel mark
once again. It can be argued that this market can possibly retest the life of
contract highs between now and harvest.
Currently, there
isn't anything dramatic going on in the wheat market. Even though demand
continues to exceed USDA projections, and some of the
Marketing Strategy.

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Winter Cover Crops – Monitor
Your Soil Moisture Levels Closely - Richard W. Taylor, Extension
Agronomist; rtaylor@udel.edu
The
wet weather pattern of the past 16 months seems to have shifted to a drier
pattern in at least some areas of Delmarva.
Of course, this shift may only be temporary but growers and consultants
should closely monitor the current pattern in which we find ourselves. Although soil moisture levels are still quite
good in most areas as spring temperatures begin to rise and cover crops begin
to green up and grow rapidly, soil moisture use rates will accelerate. In fields where rye, wheat, or other crops
have been planted as cover crops, growers should carefully monitor both surface
soil moisture and subsoil moisture to ensure that the cover crops do not dry
out the soil too much. This will be
especially true towards the end of the month and the beginning of April when
the small grain cover crops will begin jointing and evapotranspiration rates
rise. Cover crops should be killed or
plowed under before they lower soil moisture levels to the point that the following
crop’s emergence and early growth are likely to be affected.
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Nitrogen Management Under
Field Restrictions - Richard
W. Taylor, Extension Agronomist; rtaylor@udel.edu and
Whether
an individual field can not be accessed because of restrictions such as those
applied under the Avian Influenza (AI) emergency or because of wet soil
conditions, sometimes growers will have problems applying enough N to their
small grain crop. As part of contingency
planning in case the AI problem spread, we explored the options open to growers
to physically enter fields with ground equipment either because of restrictions
or wet field conditions. The option
likely remaining is to fly nitrogen (N) onto the small grain crop.
Manure
applications to small grains depend on a field or grower’s location with
respect to identified poultry farms with AI.
Be certain to check for and follow the latest restrictions on applying
manure and doing other field work before proceeding with small grain
fertilization.
Many
fields of small grains do not look very healthy at this time, and could use an
application of N to stimulate tillering and early spring growth. Aerial applications are limited because of
weight restrictions, but it should be possible to apply from 100 to 150 lbs of
ammonium nitrate per acre or 100 lbs urea per acre (the latter can be
considered as long as air temperatures remain below about 60˚ F and either
rain or irrigation water can be reasonably expected to occur in the next couple
of days following aerial application).
This initial application should be made before or as close to green-up
time as possible to stimulate small grain spring growth since many small grain
fields have been severely stressed due to our open winter. Keep in mind that this early N application is
too early for Warrior to be applied for insect management, but depending on the
growth stage and growth activity of the weeds, may work out for Harmony Extra
or Harmony GT application.
Additional
N fertilizer should be applied by ground rig if such activity is allowed in
your geographic area before jointing (Feeke’s growth stage 5 when the first
node is visible above the soil surface).
Although expensive, a second aerial application should be considered if
you can not get back into a field. Two
aerial applications can provide from 66 to 90 lbs N/A depending on fertilizer
source and application rate. You should
be able to achieve close to 90 percent of the maximum barley yield with around
50 to 60 lbs N/A. For wheat, you’ll need
80 lb N/A to achieve 90 percent of maximum level.

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You
may obtain copies of the Pest Management Recommendations for Field Crops 2004
from the Research & Education Center by mail, cost is $15.00 (includes
shipping and handling), or purchase a copy for $13.00 by stopping by the
Research & Education Center in Georgetown.
Please use the enclosed form and make checks payable to “
![]()
UPCOMING MEETINGS:
ATTENTION
BEEF CATTLE PRODUCERS!
![]()
![]()
YOU’RE INVITED!
All Cattlemen
on the
If
you have any questions contact Chris Breeding at (302) 363-1080 or Ron Wright
at (302) 398-3219.
Susan Truehart Garey, Extension Agent Animal
Science,
![]()
Beekeeping Short Course
Course Fee $25 (individual/family); Youth (18 or less) $10
Lunch included.
Topics to be covered:
¨
Honey Bee Biology
¨
Basic Beekeeping Equipment
¨
Honey Bee Diseases & Parasites
¨
In the Apiary
¨
Care & Feeding of Your New “livestock”
¨
Where Do We Go From Here??
¨
Time & Labor Saving Tips/Suggestions
Registration required.
For more Information on the Program Contact Dewey Caron,

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|
http://www.rec.udel.edu/TopLevel/Weather.htm |
Weeks of March
1 to
|
|
Rainfall: |
|
0.04
inches: March 2 0.42
inches: March 6 0.11
inches: March 8 0.05
inches: March 10 |
|
|
|
Air Temperature: |
|
Highs
Ranged from 76° F on March 5 to 42° F on March 10. |
|
Lows
Ranged from 52°F on March 2 to 30° F on March 9 & 10. |
|
Soil
Temperature: |
|
49°F
average. |
|
(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:

Cooperative
Extension Education in Agriculture and Home Economics, University of Delaware,
Delaware State University and the United States Department of Agriculture
cooperating. Distributed in furtherance
of the Acts of Congress of May 8 and
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