Group Title: Agronomy Notes
Title: Agronomy notes
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 Material Information
Title: Agronomy notes
Uniform Title: Agronomy notes (Gainesville, Fl.)
Physical Description: v. : ill. ; 28 cm.
Language: English
Creator: Agronomy Department
Florida Cooperative Extension Service
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida.
Place of Publication: Gainesville
Publication Date: August 2009
Subject: Crops and soils -- Florida   ( lcsh )
Crop yields -- Florida   ( lcsh )
Agriculture -- Florida   ( lcsh )
Agronomy -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
periodical   ( marcgt )
Statement of Responsibility: Florida Cooperative Extension Service, University of Florida, Institute of Food and Agricultural Sciences.
General Note: Description based on: January 1971; title from caption.
 Record Information
Bibliographic ID: UF00066352
Volume ID: VID00115
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: alephbibnum - 000956365
notis - AER9014


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IFAS Extension

Igronom y Notes

Volume 33:8


Stinkbug Damage to Corn ............................................... Page 2

Reserving Forage for Winter Feed: Stockpiling ............ Page 2

Watch out For Asian Soybean Rust ....................................... Page 3

Weed Control
Pasture Herbicide Roundup .......................... .................... Page 5
Web-Based Pesticide Labeling Under Consideration.........Page 6

Rotating Peanut d Cotton with Bahiagrass........................... Page 4
Calendar d Field Days ............. ...........................................Page 3

August 2009

"Agronomy Notes" is prepared by: J.M. Bennett, Chairman and Yoana Newman, Extension Forage
Specialist ( i, c .i, i!1 c.,l .I B. Sellers, Extension Agronomist (; J. Ferrell, Extension
Weed Specialist (; F.M. Fishel, Pesticide Coordinator (; J.
Marois Extension Specialist ( and D. Wright, Extension Agronomist
( Designed by Cynthia Hight ( The use of trade names does not
constitute a guarantee or warrant of products named and does not signify approval to the exclusion of
similar products.


Stinkbug Damage to Corn

b irow tn.. .l an go eIa. rt a e cn la Many of the popular varieties of corn have Roundup
Seosed to w h tolerance and a Bt gene to prevent larvae feeding
S from certain insects. However, one of the most
damaging insects to corn can be stinkbug which is
.not controlled by the Bt gene.

Stinkbug damage often happens when a crop nearby
is drying down as corn begins to silk and tassel.
Stinkbugs move to the developing ear of corn and
Swill stink through the shuck. The point at which it
stinks causes the cob to stop development on that
.. .... '. . ..,i . t e.i. side of the ear while the back side of the ear
continues to grow resulting in a banana shaped ear.
o Shuck development may also stop, or the ear curves
enough that it is exposed as shown the in pictures
below. Stinkbugs can be hard to detect but the
damage is easy to see. In the pictures, note both the
brown and green stinkbug on ears. This damage can lead to poor grain quality since it leaves grain
exposed to weather and other insects as it continues to mature and dry down. The characteristic damage is
a banana shaped ear.
Dr. David Wright, Extension Agronomist
North Florida REC, Quincy,

Stockpiling is one method of utilizing forage grown during peak periods for use during periods of deficit.
In Florida, this practice will leave a standing hay crop in the fall for use later when there is not much
grass growth. Stockpiling is common in central and south Florida because of the milder winters that
provides an opportunity to reduce the winter hay-feeding costs.

Stockpiling grass should be done by late summer. Letting the grass grow too early in the summer (June,
July, or early August) is not recommended because the grass will become too mature and by November,
cattle will likely refuse to eat it. Allowing grass accumulation too early in the season will also encourage
the buildup of thatch which is ideal for spittlebug proliferation resulting in damage to the grass. The area
to be stockpiling should have animals removed by mid August, and the area fertilized in September or
October. The resulting quality of the stockpiled grass will depend on the management practices and
climate conditions. Most grasses used for stockpiling like limpograss (Hemarthria spp) or Pangola
(Digitaria spp) will maintain a relatively high digestibility with increasing maturity. However, the
decline in nutritive value does not stop, therefore, the stockpiled grass should be fed before hay or other
feed sources are used.

Dr. Yoana Newman, Extension Forage Specialist

Agronomy Nofes Pae

Watch Out For Asian Soybean Rust

Asian Soybean Rust has been found earlier on soybean this year than in
other years. Much of the reason for this is the frequent rain fall. High
temperatures on a few occasions have slowed the spread but early
indications are for more rust than in past years.

There are sentinel plots across north Florida. The disease may be hard
to detect early in the season if you are not familiar with it. Look for
small pustules on the underside of the leaf; these lesions will not
usually have a yellow halo around them until an advanced stage
(shown in the picture left.) Many other leaf spots will have a yellow
halo around the spot.

It is advisable to consider a fungicide application at early bloom if
infected kudzu or soybeans are found near your fields. If there are other soybeans in the area that have
been planted earlier, late planted soybeans may be at a higher risk to have a severe outbreak. Later
planted soybean has a higher chance of being infected and causing yield loss than early planted soybeans.

Dr. David Wright, Extension Agronomist James Marois, Extension Agronomist
North Florida REC, Quincy, North Florida REC, Quincy,

August 1-2 Florida Small Farms & Alternative Enterprises Conference
Kissimmee (Registration discount if received by June 1.)

August 4, 11:00am UF Historical Marker Unveiling, UF McCarty Hall A
(northside of building) commemorating 100th Anniversairy of Florida 4-H

September 15-17 Annual Georgia Peanut Tour, Douglas, Fitzgerald, and Tifton, GA

September 15-18 International Citrus and Beverage Conference, Clearwater Beach

September 22-24 Southeast Herbicide Applicator Conference, Panama City Beach

October 20-22 Sunbelt Ag. Expo, Moultrie, GA

October 28th 2009 Florida Ag Expo
Gulf Coast REC, Balm

November 1-5 ASA, CSSA, SSSA annual meeting, Pittsburgh, PA.

November 14 Florida 4-H Centennial Gala, Jacksonville

November 15-17 Energy Conference, Orlando

Agronomy Notes Pag

Impacts of sod based rotations on crops Our research has shown the value of rotating peanut and
cotton with bahiagrass. Growers know that rotations work. However, there are rotations that can add
extra benefits to the whole farming system.

Our research over the last 8 years has shown that peanut yields without irrigation when following
bahiagrass are similar or higher than irrigated peanut following two years of cotton. Likewise, we have
been building organic matter by 0.1% per year. The impacts of the two systems on cotton are shown in
the picture below. Even though cotton is grown the second year after bahiagrass (following peanuts),
tremendous differences in growth and yield have been observed. The differences between these two
systems have been getting larger in terms of yield and quality of both the summer and oat/rye cover
crops. The bahiagrass system had been compared to the best conservation technology farming methods
that we have available.

Dr. David Wright, Extension Agronomist James Marois, Extension Agronomist
North Florida REC, Quincy, North Florida REC, Quincy,

0 N 60 Ibs N/A

60 Ibs N/A

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Employment Opportunity-
Affirmative Action Employer authorized to provide research educational information and other
services only to individuals and institutions that function without regard to race, color, sex, age,
handicap or national origin. For information on obtaining other extension publications, contact your
county Cooperative Extension Office. Florida Cooperative Extension Service/Institute of Food and
Agricultural Sciences/University of Florida/Larry Arrington, Dean.

For many years there were few herbicides entering the pasture market. All the emphasis at the corporate
level was for new corn and soybean products in the mid-west while pastures were a mere afterthought.
However, this trend has changed and new products are now flooding into this market. Below are some
recent additions to our weed control toolbox.

Cleanwave is a co-mix product containing both fluroxypyr and trace
amounts of aminopyralid. Though originally developed for weed
control in wheat in the plains states (hence the name, Clean-wave), it
has shown great promise for pasture weed control in Florida. Fluroxypyr is the active ingredient in Vista
and one of the components of PastureGard. It has been determined, after extensive testing, that
fluroxypyr is highly effective on dogfennel and many other weeds. Experiments conducted by the
University of Florida IFAS have found that 16 oz of Cleanwave + 32 oz of 2,4-D is highly effective
on dogfennel that is up to 36" tall. It has also proved to be effective on prickly pear when applied in the
fall at a rate of 50 oz/A. At approximately $65 per gallon, Cleanwave will control a number of weeds at
a relatively low cost.

GrazonNext is not a new herbicide, just a new name. GrazonNext is
the exact same herbicide as Forefront (aminopyralid + 2,4-D), but was
developed to be sold in the western US where Grazon P+D (picloram
+ 2,4-D) was heavily used. Grazon P+D is highly effective on a number of species and relatively
inexpensive. But, the picloram component has environmental quality concerns that has led Dow
Agrosciences to reduce the emphasis on this herbicide. To do this, GrazonNext was introduced into
these "P+D" markets at a greatly reduced price relative to Forefront. Currently, Forefront is
approximately $60 per acre while GrazonNext is between $35 and$40. Although Florida is not a P+D
state, the decision was made to sell GrazonNext here and pass the savings along to the rancher. At
approximately $9 per quart and a 0 day grazing restriction, GrazonNext becomes a very attractive option
for thistle, pigweed (carelessweed), tropical soda apple, and many other species.

Controlling sedges in hay fields is a constant struggle. Most
herbicides possess no activity on this species, or you choose to use a
product that is highly injurious to the forage grass. But this dilemma
may be over. Monsanto has recently began to sell Outrider (sulfosulfuron) for sedge control in pastures.
This herbicide is labeled for use in established bermudagrass and bahiagrass. Application of 1.33 oz/A
is effective on a wide variety of sedge species while causing little or no forage grass damage. Outrider
will cost approximately $20 per acre. Outrider is not a broad-spectrum pasture herbicide, but the
effectiveness on nutsedge is remarkable.

Distinct is a relatively new herbicide from BASF Corporation that
combines dicamba and diflufenzopyr. Though little testing with this
herbicide has been done, it is expected to add significant activity
when used with herbicides such as 2,4-D and Weedmaster. The addition of 2 or 4 oz/A of Distinct will
add approximately $5-10/A and will likely assist in controlling species that are difficult to manage with
2,4-D alone.

Dr. Brent Sellers, Extension Weed Specialist
Range Cattle REC, Ona, FL,

Dr. Jason Ferrell, Extension Weed Specialist;

Agronomy Notes Pc


Web-Based Pesticide Labeling Under Consideration

Since 2007, EPA has been considering a web-based approach of distributing pesticide product labels to
end users. If this will happen, traditional paper-made product labels will be replaced. What is EPA
trying tofix? EPA's hope is that this approach will simplify information and provide the latest in
product label amendments to the user. Ultimately, the system will provide greater protection of
environmental and public health.

What willpesticide handlers have to do? Handlers would have to contact the
official EPA web address or a toll-free telephone number listed on the product label
to obtain use directions. This contact information would replace the product's use
:- directions, advisory statements, and other selected information.

What will remain unchanged on the product container? On containers that are
S distributed, the product ingredients, a reference for use directions, the product's
classification, such as restricted, storage and disposal directions, registration and
establishment numbers, warning statements, and first aid statements will remain.

How does a pesticide handler 1 i th, ut web access obtain label information? Those
without access to the web site can call the toll-free telephone number, make a
request, and EPA will send the label information, either by fax or the U.S. Postal

Obviously, there are concerns and unanswered questions of such a system:
Whether or not the web will become mandatory as the only means for obtaining
Label changes may occur within hours following product purchase, possibly
resulting in a subsequent use violation. Who would be liable in such an event?
Who is responsible for ensuring proper label information is obtained the
product retailer, or the user?
What is the true definition of a label the actual paper itself, the image on a
computer monitor or cell phone?
The U.S.D.A. recently estimated that only 55 percent of rural farms have web access, and of those,
47 percent are still using a slow and unreliable dial-up connection.
In the event that a product is stored for an extended period of time, such as until the next growing
season, it may become unusable as its label may change. This poses a disposal issue.
Currently, purchasers can feel confident that the paper label with the product they have purchased is up
-to-date and legitimate. Under a web-based system, how will the user know the time period of label
validity? EPA is looking at a few options. One is that a production date is placed on the container and
requires that the user obtain the label in effect on or after that date. Another is that the web-based label
would have a defined lifespan. Following the expiration date, the user would need to obtain a new

These are likely only a few of the unanswered questions that such a system would present. If and
when this goes through the EPA process, there will certainly be more issues evolve with such a

Dr. Fred Fishel
Pesticide Information Director Agronomy Notes

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