Volume 12, Issue 5
April 23, 2004
Volume 12, Issue 5
April 23, 2004
Vegetables
Planting Progress
and Transplanting Hints for Melons –
Pea
planting has reached the 60-70% level at this time. Warm, sunny weather has promoted growth after
the week of cool, wet weather.
Sweet
corn planting began in late March with plastic covered rows; conventional
plantings began in early April.
Processing sweet corn plantings began last week and have moved along
well.
Potato
planting is nearing completion in most cases.
After
the extended period of rain last spring, we all feel fortunate for the decent
planting season we’ve experienced to date.
Soon
watermelon and cantaloupe transplants will be set out (there are some out there
now) in full force. No doubt some of the
plantings will experience stress from one factor or another, or some
combination of factors. Hardening off
the transplants before transplanting will help the plants withstand some of the
stress, especially weather-related stress.
Reducing the amount of water used, lowering temperatures, and limiting
fertilizers will cause a “check” in growth, known as hardening. When hardening the vine crops, do not lower
the temperature more than 5oF below the recommended minimum
temperatures for growth, which is 65oF. Lower temperatures causes chilling that can
injure plants and delay re-growth after transplanting.
Many
times we pull transplants out of the greenhouse and put them on a wagon. It may be important some nights to pull the
wagon in the barn or shed to avoid excessively low temperatures.
The
quicker the transplants “grab hold” and grow, the better chances for an earlier
maturing, high yielding crop.
Vegetable Crop Insects - Joanne Whalen, Extension IPM
Specialist; jwhalen@udel.edu
Asparagus.
Asparagus beetle adults are now active, so be sure to watch for egg
laying as spears emerge. A treatment is recommended if 2% of the spears are
infested with eggs. Since adults will also feed on the spears, a treatment is
recommended if 5% of the plants are infested with adults. Sevin, Lannate,
Ambush, or Pounce will provide control.
Cabbage.
Continue to sample for imported cabbageworm and diamondback larvae in
cole crops. A treatment is recommended if you find 5% of the plants infested.
If both species are present, Avaunt, the
Bt insecticides, Proclaim and Spintor will provide control.
Melons.
Seed corn maggot flies can be found laying eggs in fields, especially
where chicken manure or green manures have been recently plowed under. A seed corn
maggot control should be considered if
you are planting into fields with these conditions. A broadcast application of
diazinon before planting has provided control, if the application is applied
close to planting. The use of Admire or
Platinum through the drip or Furadan applied immediately before transplanting
may help to provide suppression of seed
corn maggot.
Peas.
As soon as fields start to bloom, it is important to sample fields on a
weekly basis for pea aphids. You should sample for pea aphids by taking 10
sweeps in 10 locations and counting the number of aphids per sweep. A treatment
is recommended if you find 50 or more aphids per sweep. Dimethoate or Lannate
will provide aphid control. Be sure to check the labels for application
restrictions during bloom.
Vegetable Diseases - Bob Mulrooney, Extension Plant
Pathologist, bobmul@udel.edu
Article on Phytophthora
Blight on Cucurbits.
There
is an excellent feature article this month on Phytophthora blight on cucurbits
at the American Phytopathological Societies’ website. It makes for good plant
pathology reading. http://www.apsnet.org/online/feature/cucurbit/
Field Crop Insects - Joanne
Whalen, Extension IPM Specialist;
jwhalen@udel.edu
Alfalfa.
If you have not checked your fields for alfalfa
weevil larvae, it will be important to sample during the next week (5-7 day period).
We can easily find second instar larvae in fields throughout the state. Using
http://maps.zedxinc.com/cgi-bin/site.cgi?location=2&user=testuni#
Once larvae are detected, the following thresholds
should be used: up to 11 inches tall - 0.7 per stem; 12 inches - 1.0 per stem;
13 - 15 inch - 1.5 per stem; 16 inches tall - 2.0 per stem and 17-18 inches
tall - 2.5 per stem. Numerous pyrethroids are now
labeled for alfalfa weevil including Ambush, Baythroid,
Mustang MAX, Pounce and Warrior. Furadan, Imidan, Lorsban, Lannate and Steward will also provide control.
Field
Corn.
Black cutworm traps catches are generally still low
( 2-3/trap/week) in most locations except in the Little Creek area where
catches have increase to 10 per week (see trap catch table on the last page or
look at our web-page at http://www.udel.edu/IPM/traps/currentbcwtrap.html).
Moth catches of 9 to 15 moths per 7-day period can indicate a moderate to high
potential for outbreaks. You can expect to see cutting activity around 300
degree-days, base of 50 degree F from peak moth activity.
As
soon as corn emerges, watch for early signs of cutworm leaf feeding which could
appear as small pinholes when larvae are small. This damage often provides an
indication of where you will see cut plants in the next week. No treatment will be needed until you find 10
% leaf feeding or 3% cut plants on 1-2 leaf stage corn. On 3-4 leaf stage corn,
the treatment threshold is 5% cut plants. A pyrethroid or Lorsban will provide
cost-effective control. Since cutworms are nocturnal, applications applied
later in the day or in the evening will provide the best control.
As
corn emerges, you should also watch for bird damage. You can distinguish bird
damage from cutworm damage by the pattern in the field: generally longer strips
of damaged plants, plants pulled out of the ground, and/or plants cut high that
are compressed at the base of the stems. Although birds can cut plants off at
the soil surface, they tend to pull plants out of the ground. In addition, if
you look closely you will see " bird prints" near the missing plants
or holes were birds have pulled plants out of the ground so do not confuse it
with cutworm damage.
Small
Grains.
We
are starting to find low levels of cereal leaf beetle eggs in wheat and barley
in
If
cereal leaf beetle is the predominant pest, Furadan, Lannate or Malathion can
be used on barley. Furadan can not be applied once the heads emerge. In
addition to the previous products, Mustang and Warrior can also be used on
wheat for cereal leaf beetle control. If armyworm is the predominant species,
Sevin, Lannate and Penncap-M can be used on barley. Sevin and Penncap-M should be used on smaller
larvae. In wheat, all the previous products as well as Mustang and Warrior can
be used for armyworm control. If sawflies are the predominant pest, your only
option is Lannate in barley. In wheat, you can use Lannate, Mustang or Warrior
for grass sawfly. In barley, your only control option if all 3 insect pests are
present is Lannate. In wheat, your
options for control of all 3 insect pests include Lannate, Mustang or Warrior. Remember,
all uses of ethyl parathion ended on October 31, 2003
Field Crops Diseases - Bob Mulrooney, Extension Plant
Pathologist, bobmul@udel.edu
Wheat.
The
stunted wheat that was submitted several weeks ago for a diagnosis turned out
to be a combination of wheat soilborne
mosaic virus and wheat spindle
streak mosaic virus. Barley yellow dwarf was not detected. The wheat is
already growing out of the symptoms. Once warmer weather arrives this is what
usually occurs.
Both
viruses need wet soil in the fall for transmission of the virus by the fungus Polymixa graminis. The leaves were
mottled, some had a reddish purple coloration, most were chlorotic and stunted.
Should You Leave Princep Out With
Later No-Till Corn Planting? - Mark
VanGessel, Extension Weed Specialist; mjv@udel.edu
In the past, it was recommended to use Princep when
the cornfields were sprayed early, then switch to Bladex after mid-April. I have been asked whether it is worth it to
include Princep as a component of no-till spray mixes since Bladex is no longer
available. Princep will not control
emerged grasses, but it will provide residual control. But be sure to include paraquat or glyphosate
to control the grasses that have already emerged, then Princep will be there to
control late emerging grasses. In fields
with a history of crabgrass and fall panicum problems, it is a good idea to
include Princep even with later plantings.
Effectiveness is the
First Consideration for Weed Control
- Mark VanGessel, Extension Weed Specialist; mjv@udel.edu
When deciding which weed control option to use, the
first question should not be what does it cost.
What is your approach to weed management in the field? Is it achieving excellent weed control
because rotational crops have limited herbicide selection, or is it achieving
the level of weed control that will not reduce yield or something in
between. Either way, selecting the
herbicide program based on effectiveness is more critical than selecting it on
cost. An in-expensive option that does
not control key weed species is going to be more costly in the end.
In planning your weed management for a given field,
consider what happened last year in that field.
A number of fields throughout the state had excessive rain last year and
the soil-applied herbicides could not handle all the weeds. Those fields that had a large number of weeds
go to seed last year, so plan accordingly.
Remember, many of our hard to control weeds require a postemergence
herbicide for effective control. Knowing
that you are going to be spraying a postemergence herbicide may allow you to
lower your soil-applied herbicide rates.
The result can be less money in a preemergence program knowing you will
need a postemergence spray. For assistance
in selecting the most effective herbicides, refer to the 2004 Weed Management
Guides for Delaware. There is one for
corn and one for soybeans available free from the county offices, on the
internet at www.rec.udel.edu (under
publications) or calling 302/856-7303 and asking for
Grain Marketing Highlights - Carl German, Extension Crops Marketing Specialist; clgerman@udel.edu
Theories Abound on Where
Commodity Prices are Headed?
Commodity
futures contracts have a tendency to retrace themselves over the life of the
contract. This may be the 'saving grace' for anyone that chose not to forward
price any of their new crop corn, wheat, and/or soybean crops as recent
opportunities were presented, prior to April 15th. April 15th marked the first
time that the 50 cent limit was achieved in soybean futures, giving rise to
alarm in the minds of many as new crop soybean prices fell 50 cents per bushel
that day. That 50 cent drop in soybean futures amounted to $20.00 per acre
assuming a 40 bushel per acre yield.
New
crop plantings are off to a record start in the corn belt while weather
continues to be somewhat of a mixed bag. Early planted U.S. corn crops have the
potential of producing very large to record yields, with average or better
weather conditions. We will all ponder the question, "Will commodity
futures make a comeback?" "Will they retrace themselves prior to contract
expiration?" In the case of new crop soybeans and corn we have until the
months of November and December to find out. It all boils down to the weather,
less than ideal growing conditions will see these markets retracing the life of
contract highs achieved the spring of '04 for new crop corn and soybeans.
During March for corn and March and April for soybeans, Dec '04 corn futures
hit $3.42 per bushel, and Nov '04 soybean futures reached $7.99 per bushel. The
only certainty in these markets at the present time is that weather conditions
in the corn belt will play a large role in determining whether we get back to
those recent highs established in March and April? For the moment, we have to
assume that we will.
Delaware Agri-tourism
Association
invites you to attend the
1st Annual
Delaware Agri-tourism
Membership Meeting!
WHO: Open to all people interested or involved with
on-farm entertainment activities
Where: Delaware Department of Agriculture,
WHEN:
April 27,
2004 6:30 pm—9 pm
AGENGA: Dinner, Special Guest
Speakers, DDA & Extension Updates
COST: $8.00 per person for
Dinner and Program
RVSP
by April 23, 2004 to Amanda
Brown at 302 698-4523 or by email: amanda.brown@state.de.us
2004 Wye Research Center’s
Spring Strawberry Twilight Meeting
What: The 2004 Wye Research Center’s
Spring Strawberry Twilight
Meeting
Where:
Wye Research and Education Center Queenstown MD
When: Thursday, May 20, 2004
6:00 PM
Who: University and USDA Small Fruit
Specialist
What will I see?
1)
2003/04
Annual plasticulture system: evaluation of Fall deployment date of floating row
covers, planting date and varieties.
2)
High
tunnel production for Fall and Spring harvest
3)
Greenhouse
production system for early Spring harvest, utilizing, dormant, multi-crowned
plants.
Pre-registration
not required.
For
more information and directions:
Contact:
Debby Dant at 410-827-8056, ddant@umd.edu or
Michael Newell at
410-827-7388,
mnewell@umd.edu
Date
Change for
University of Maryland
Wye
Research & Education Center Spring Crops Tour
May
19, 2004
6:30
p.m.
The Wye Research and Education Center's Spring Crops Twilight
tour, originally scheduled for May 20, has been rescheduled to May 19th at
6:30. Topics of interest will be small
grain varieties, current weed, disease or insect issues and any topic of
immediate agronomic concern.
Refreshments will be supplied.
Event will be held rain or shine.
Call Mark Sultenfuss at 410-827-7388 with any questions or topic
suggestions.
Week of April
15 to April 22, 2004
|
|
Rainfall: |
|
0.18
inches: April 15 |
|
Readings
taken for the previous 24 hours at 8 a.m. |
|
Air Temperature: |
|
Highs
Ranged from 86°F on April 18 to 60°F on April 15. |
|
Lows
Ranged from 65°F on April 19 to 34°F on April 16. |
|
Soil
Temperature: |
|
62°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:
Sussex County Extension
Agent – Horticulture
University of Delaware
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 June 30, 1914. Delaware Cooperative
Extension, University of Delaware. It is the policy of the Delaware Cooperative
Extension System that no person shall be subjected to discrimination on the
grounds of race, color, sex, disability, age or national origin.
2004 Black Cutworm Pheromone Trap
Counts Trapping date: April 13 – April
19, 2004 |
||||
|
Bridgeville |
2 |
Little
Creek |
10 |
|
|
Delmar |
3 |
Magnolia |
1 |
|
|
Ellendale |
0 |
Milford |
0 |
|
|
Felton |
1 |
Millsboro |
0 |
|
|
Frederica |
2 |
Milton |
0 |
|
|
Georgetown
(UD REC) |
3 |
Sandtown |
1 |
|
|
Greenwood |
1 |
Seaford |
0 |
|
|
Harrington |
0 |
Selbyville |
0 |
|
|
Kenton |
1 |
Smyrna |
2 |
|
|
Laurel |
2 |
Wyoming |
1 |
|
|
Leipsic |
0 |
|
|
|
|
Lewes |
4 |
|
|
|
|
Lincoln |
0 |
|
|
|
|
|
|
|
|
|