Volume 11, Issue 3
April 11, 2003
Volume 11, Issue 3
April 11, 2003
Fruit
Fruit Insects
-
Section 18 Approved for Provado
on Stone Fruits.
Provado 1.6F has been approved for use on peaches,
nectarines, plums and apricots in
A maximum of 4 applications
at the rate of 5-6 fl. oz. of product/A (0.06-0.08 lbs. a.i./acre)
of Provado 1.6F may be made by ground equipment. No more that 24 ounces of the product (0.32
lbs a.i.) may be applied per acre per year.
Vegetables
Watermelon
Promotion –
The National Watermelon Promotion Board has received approval from the USDA for a new logo that emphasizes watermelon as the “lycopene leader in fresh produce.” Research has indicated that lycopene, a cartenoid, may help reduce the risk of prostrate cancer and heart disease. Another good reason for consumers to buy Delmarvalous watermelons.
Wet Conditions
and Potato Weed Control Decisions –
The continuing wet conditions have obviously delayed much of the potato planting progress. In some cases, the weather may have eliminated the opportunity for pre-emergence treatments of herbicides. However, there are excellent post-emergence materials available.
If no pre-emergence materials were applied, a Matrix (rimsulfuron) and Sencor (metribuzin) combination will control many grass and broadleaf weed species. While the Matrix rate is 1 ounce/acre, a reduced rate of Sencor (metribuzin) at 1/3 lb./acre should be used when mixed with Matrix. Use non-ionic surfactant at 1 quart per 100 gallons of spray. Always check the label for additional instructions and restrictions. This must be applied before the potatoes are 14 inches tall. Of course, the earlier the application, the better the weed control.
The post-emergence grass materials, Select or Poast, can also be used as separate applications to control escaped grasses.
Vegetable Diseases
–
Ozone injury on watermelon.
Bifacial necrosis of old watermelon leaves.
(Mid-August.)
Photo
taken from the USDA-ARS, North Carolina State University Air Quality Research
Unit at the following address:
http://www.ces.ncsu.edu/depts/pp/notes/Ozone/o3waterm.html
Ozone
Damage in Watermelons.
Ozone injury to
watermelons is common in
Grain Marketing Highlights -
Supply and Demand Report Viewed as
Uneventful
Commodity
analysts are reporting no big surprises from the April 10th Supply and Demand
report. The numbers most watched in this report were ending stocks for
Corn
ending stocks are now listed at 1.009 billion bushels vs. the average trade
guess of 999 million bushels. Ending stocks for corn were reported to be 5
million bushels less than last month's estimate.
Soybean
ending stocks are down to 145 million bushels, vs
trade guesses ranging from 125 to 150 million bushels. Soybean stock estimates
are down 15 million bushels from last month.
Wheat
stocks are down 20 million bushels from last month. The decrease in wheat
stocks, now placed at 445 million bushels is due primarily to a 25 million
bushel increase in domestic feed and residual use and a 5 million bushel
increase in imports on the supply side.
CBOT Launches Mini Agricultural Futures
Contracts
The
Chicago Board of Trade launched CBOT mini corn, wheat, and soybean futures
contracts on Monday, April 7. The trading hours for these 1,000 bushel
contracts will be from
Is It Too Late to Apply Nitrogen to Small Grains? - Richard W. Taylor, Extension Agronomist; rtaylor@udel.edu
;
The question being raised after the most recent period of
bad weather is if it still is worth while fertilizing small grains. An important component of the answer is the
determination of the stage of growth of the crop. Where you haven’t been able to apply
fertilizer yet, you should take the opportunity to scout a field for the crop’s
growth stage while you wait for it to dry.
Examine a number of plants across the field and determine growth stage
by looking closely at the primary tillers on each plant. Check tillers to see if you can feel a
swelling that indicates node development.
Another way is to pull back leaf sheaths to expose the growing point and
see if more than one or two internodes (the space between two nodes) are
present. Also, observe how far above the
soil surface the growing point is. The
jointing stage of growth begins when the first node appears above the soil
surface and jointing progresses as more and more nodes occur above the soil
surface until boot stage when the seed head can be felt within the leaf
sheaths.
Once the space between the nodes begins to lengthen and
pushes the growing point that ends in the seed head above the soil surface, the
likelihood of doing at least some damage to the crop by driving across a field
to spread fertilizer is great. After
several internodes are visible, the chance of having a large impact on yield by
applying nitrogen (N) diminishes.
Another helpful indicator will be the intensity or greenness of the crop
or signs of N deficiency on the lower leaves.
The number of leaves per plant showing N deficiency symptoms relates to
the amount of N stress and that corresponds to loss of yield potential. When combined with plants at later stages of
development (late jointing or early boot), the damage caused by N stress
reaches the point where additions of N will no longer boost yields enough to be
profitable. The earlier you can apply N
the more yield response you are likely to see.
By boot stage, N will have little impact on yield potential although it
can still influence the grain N content.
Another question asked is whether wheat that recently came
up will yield? This question is harder
to answer because wheat requires a period of cold temperatures to change it
from vegetative state to a reproductive state.
Winter wheats require more cold weather than
spring wheats and southern varieties of winter wheat
can be switched to a reproductive state by fewer days of cold than varieties
developed further north. The problem
with deciding if a field will move to the development of grain (yield) is knowing when the crop germinated enough for the cold
temperatures to begin the process of vernalizing the
crop and switching it to a reproductive state.
With a microscope or a very good hand lens (and good eyesight), you
might be able to dissect plants and identify the developing panicle if it has
switched to the reproductive state. At
the growing point even when it is very tiny, you can identify the developing
panicle or seed head since it looks like a miniature wheat head. Even if you find that the crop has vernalized, the yield potential is an open question. Experience suggests wheat that emerges in
late February can produce 50 to 60 bu/A but we’ve not had experience with wheat emerging later
than that date.
Avoiding Leaf Burn from UAN on
Small Grains - Richard W. Taylor, Extension Agronomist;
rtaylor@udel.edu;
Several years ago Ron Mulford, the
farm manager for
If you have to apply UAN under warm conditions, you may want
to follow the guidelines below to possibly reduce the potential for leaf
burn. Since weather conditions may be
forcing many producers to apply N much later than they like, preventing even
the mildest of stress such as the temporary leaf burn UAN can cause can be
worth the extra effort.
|
Table 1. Approximate dilutions for UAN solutions
when topdressing small grain to reduce the potential for leaf burning under
warm conditions (60˚F and higher). |
|||
|
Gallons of UAN |
Gallons of Water |
N Application Rate |
Total solution
volume |
|
Lb N/a |
Gallons/acre |
||
|
28% UAN |
|||
|
13.4 |
None |
40 |
13.4 |
|
16.8 |
4.2 |
50 |
21 |
|
20.1 |
4.9 |
60 |
25 |
|
23.5 |
5.5 |
70 |
29 |
|
26.8 |
6.2 |
80 |
33 |
|
30% UAN |
|||
|
12.3 |
None |
40 |
12.3 |
|
15.4 |
4.6 |
50 |
20 |
|
18.5 |
5.5 |
60 |
24 |
|
21.6 |
6.4 |
70 |
28 |
|
24.6 |
7.4 |
80 |
32 |
|
32% UAN |
|||
|
11.3 |
None |
40 |
11.3 |
|
14.1 |
4.9 |
50 |
19 |
|
17.0 |
6.0 |
60 |
23 |
|
19.8 |
7.2 |
70 |
27 |
|
22.6 |
8.4 |
80 |
31 |
Preemergence Herbicide Rates In Corn
-
There have been
changes in formulation and ratios of products for many pre-packaged herbicides
over the past few years. As a result,
check the label for your product of choice since often the new formulations
recommend lower use rates than what as previously labeled. Below is a chart on rates of the most common
pre-packaged mixtures used in the area, and general use rate and what the
products they are providing:
|
Herbicide |
Rates |
atrazine |
chloroacetamide (grass herbicide) |
|
|
Bicep II Magnum |
1.6 qts |
1.24 qt |
1.0 pt Dual II Magnum |
|
|
Fultime |
2.7 qts |
1.1 qt |
2.0 qt Topnotch |
|
|
Guardsman Max |
1.5 qts |
1.25 qt |
14 oz Outlook |
|
|
Harness Xtra 5.6L |
1.7 qts |
1.1 qt |
0.76 qt Harness |
|
|
Lumax |
2.5 qts |
0.625 qt |
1.76 pt Dual II Magnum AND 5.4 oz Callisto ** |
|
**Callisto is not
a chloroacetamide
Conventional
Soybean Herbicides -
I have had a number
of questions about herbicides for non-Roundup Ready soybeans. There is interest in growing conventional
varieties for a number of reasons. Most
sound herbicide programs will require a broadleaf plus a grass herbicide at
planting. The Delaware/New Jersey
Soybean Weed Management Guide available free at the county offices or online at
http://www.rec.udel.edu/weed_sci/WeedPublicat.htm
will provide useful information for selecting herbicide programs for the
specific weed problems you need to handle.
As always, there is not one program available that will fit all
situations. Be sure to consider all
factors, including effectiveness, application timing, and rotational
restrictions. Contact your county agent
if you want to review your options.
Supplemental
Labeling of Roundup Products for Glyphosate-Resistant
Horseweed (Marestail) -
Monsanto has issued
supplemental labels for control of glyphosate-resistant
horseweed in all of DE, NJ, and eastern shore of MD. For all
Monsanto’s glyphosate products (Roundup Ultra, Roundup UltraMax, and Roundup WeatherMax),
they are requiring 1 pt of 2,4-D to be applied to
plants 6 inches or less. I have concerns
that the rate of 2,4-D will not control the glyphosate-resistant horseweed, and I would encourage the use
of 1 qt/A of 2,4-D (in areas where it is appropriate and where a 30 day
interval between application and planting is acceptable) for better and more
consistent control.
Do Not Overuse
Roundup Ready Crops -
Avoid the temptation
to use Roundup Ready corn in the same fields where you are planting Roundup
Ready soybeans. Relying on glyphosate (whether it is Roundup products, Touchdown, Glyphomax or others) every year for postemergence
weed control is not a sound, long-term weed management program. As a general rule, do not use Roundup Ready
crops more than once out of two years for a given field.
Delayed Burndowns For Corn -
Due to the spring
rains a number of fields for no-till corn have not been sprayed yet. As a result, what works when burndowns are applied in March may not work this year
because the weeds are likely to be larger than normal. Be sure to use a full rate of the
non-selective (burndown) herbicides. Gramoxone Max at
1.25 pts and full rate of glyphosate products should
be used since many of the winter annual weeds will be larger due to the later
application timing. Also, if considering
using 2,4-D, be aware there are restrictions on time from application to planting
(commonly 7 to 14 days) and it is not recommended on coarse-textured soils with
low organic matter (refer to label of the product you are using). Remember, if trying to combine nitrogen
applications with the burndown herbicides, Syngenta recommends increasing the rate of Touchdown by 0.5
to 1.0 pt/A while Monsanto does not recommend nitrogen
carriers where annual ryegrass, barnyardgrass, fall panicum, or broadleaf signalgrass
are present. Finally, if you typically
use Princep (simazine) when
burning down no-till fields early, you should still use it with the burndown mixture to help with residual control of crabgrass
or fall panicum.
Princep will not help with controlling those
plants already out of the ground, but will provide residual control.
Changes
in Pesticide Regulations as Related to Applying Pesticides When Using a Tractor
With An Enclosed Cab –
The
following information was taken from James Belote’s Accomack
Ag News, March 2003 Issue.
The American Society of Agricultural Engineers (ASAE)
is no longer certifying closed cabs as equivalent to the protection of a
respirator. As a result, when the label
requires a respirator, applicators must wear one, even if using a tractor with
an enclosed cab.
The problem has occurred because no tractor
manufacturer or government agency has declared in writing that the enclosed cab
of any tractor with its properly functioning ventilation system will provide
respiratory protection equivalent to or greater than the vapor-or gas-removing
respirator specified on a pesticide product.
As a result, growers using enclosed cab tractors and
applying products that require respirators are required to wear respirators when
in the cab.
|
http://www.rec.udel.edu/TopLevel/Weather.htm |
Weeks of April 3 to
|
|
Rainfall: |
|
0.58 inches: April 7 0.01 inches: April 8 0.94 inches: April 9 |
|
|
|
Air Temperature: |
|
Highs Ranged from 62°F on April
3 to 40°F on April 8. |
|
Lows Ranged from 44°F on April
3 to 38°F on April 8 & 9. |
|
Soil Temperature: |
|
48°F average for the week. |
|
(Soil temperature taken at
a 2 inch depth, under sod) |
Web Address for the U of D
Compiled and Edited
By:
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, Robin
Morgan, Director. Distributed
in furtherance of the Acts of Congress of May 8 and