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: December 2010
Subjects / Keywords: 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 )
Additional Physical Form: Also available to subscribers via the World Wide Web.
Additional Physical Form: Electronic reproduction of copy from George A. Smathers Libraries, University of Florida also available.
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: VID00130
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

Full Text

IFAS Extension



G. Cattle on Row Crop Land.................. Page 2
Decisions for 2011 Planting............................... Page 2
Camelina an Oil Seed Crop............................... Page 3

G. of WinterAnnual Forages.....................Page 4
FreeZe, Sorghum and Prussic A d .....................Page 4

Florida Granted 24C Labelfor Wick -Bar Appi cautions

New Core Manual for Pestiide Applicators ...... Page 6
New Drift Management Guide ..... .................. Page 6
C alendar ......................... ........................Pag e 7
r,' o

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/

"Agronomy Notes" is prepared by: Maria Gallo, Interim Chair and Y. Newman, Extension Forage Specialist -i II. J. Ferrell, Extension
Weed Specialist |i. .I. i.i I. .1.., Fred Fishel I .l.h.i .-I-. J. Marois, Plant Pathologist i- 1... iii. .1..I D. Wright, Extension Agronomist
i i. 11. .1.1 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.



Dr. David Wright, Extension Agronomist

North Florida REC, Quing

Dr. Jim Marois, Plant Pathologist

Grazing Cattle on Row
Crop Land

Row crop growers would benefit from
establishing working relationships with
cattle producers for winter grazing. Soil
sampling taken over the past two years on
crop land that had cattle grazed vs. just
cover crops in the same field had as much
as $120 worth of nutrients that were kept in
the top foot of the soil profile as compared
to just growing cover crops. Most of this
value in nutrients was in N and K but also
in other nutrients. Cotton grown after the
cattle vs. no cattle has averaged about 200
lbs. more lint per acre than where cattle
were not grazed. There was slightly more
soil compaction in the top 6 inches of the
soil profile. However, overall cattle added
benefit to cotton and would be expected to
add benefit to corn but had no impact on
peanut. Wright & Marois.

Decisions for 2011

Due to the favorable prices for row crops at
the present time, growers who make variety
selection decisions early will be able to get
the best varieties. In many cases there is
some discount for seed purchases made by
the end of the year for the coming year. The
favorable prices will make it easier for
growers to do a better job of rotating crops.
Seldom do all of the row crops have good
prices and best rotations are not followed
due to crop price. 2011 will be a good year
for peanut or soybean growers to rotate to
cotton since the prices are very favorable for
making a profit. Rotation is one of the best
practices to maintain yield of all crops in a
rotation and reduce pesticide costs.

Winter grazing and exclusion cages

Winter grazing prior to planting row crops with grazed and nongrazed areas
Photo by David Wright.

Rotations are keyto low pest pressure and high yields

Cotton, corn, peanuts, and forages rotated to maintain high yields while lower-
ing pest pressure.
Photo by David Wright.

Crops Dr. David Wright, Extension Agronomist
North Florida REC, Quing

Camelina an Oil Seed Crop

There has been much discussion about camelina as a winter
crop for Florida farmers. Camelina [Camelina sativa (L)] is a
semi-arid, old world crop used primarily for oil that has had
very little improvements done from breeding efforts. It is a
member of the Brassicaceae family which is related to canola
and cole crops. Oil content of the seed is 29-40% and is high in
omega-3 fatty acids which have been cited as having health
benefits. The meal can be fed to livestock producing eggs and
meat that is higher in omega-3 fatty acids. The interest in
camelina is not only due to omega-3 fatty acids but as a as a
renewable source of energy for high quality jet fuel. It has a
wide range of adaptation. Camelina has a fit in many different
cropping systems due to its short period of growth (70-90 days).
Camelina seedlings can survive intense cold (into the teens) and
can be planted before or after main cash crops in southern
latitudes in either the spring or fall. Even though the crop has
been grown for thousands of years, research related to
production is limited and will develop as its value increases as a -
renewable energy crop. Data from Colorado has shown that u a
water use efficiency was higher for camelina than either canola
or sunflowers. Many of the production practices being used are
taken from related crops (mainly canola). In dry climates,
camelina can replace fallow between crops to produce income
and serve as a renewable energy and rotation crop. Top: Young stands of camelina. Bottom: Camelina at
Since breeding efforts have been limited on camelina, only a harvest with a standard grain combine and grain table.
few varieties are available. It can be established with no-till Photo by David Wright
drills in firm seedbeds. Recommended seeding rate is 3-10 lbs/
A at a depth of 1 1 inch deep. A cultipacker seeder may be the best implement for establishing stands for
new growers on prepared seedbeds as they experiment with establishment. Getting a stand is a critical
component of production. At the present no herbicides are labeled for camelina. Likewise, little is known about
impacts of residual herbicides from other crops on its establishment. Currently, most university researchers
working on camelina suggest that the same restrictions on residual herbicides on canola be followed for
camelina. It is also suggested that camelina not be planted more than once every 3 years in the same field.
However, it is a very short season crop and these restrictions may be altered after field testing in Florida. Yields
of 1000-1500 lbs/A or more have been made with N application rates of 60-90 lbs/A in other parts of the
country. Soil tests should be followed for other nutrients. Direct harvesting can be done with a combine when
pods turn yellow. Like canola, reel speed is critical to keep from shattering seed during the harvest operation.
Recommended moisture for storage is 8% to keep from damage and spoilage. We do not have good
experimental information on best planting dates or nitrogen rates at the current time in Florida but trials are
under way for N rates, planting dates and planting after the major row crops (peanut, corn, cotton, and soybean)
to determine residual herbicide impacts on canola establishment and yield. In Florida at the present time, little is
known about camelina. However, camelina has been grown in south Florida and the oil has been tested as a
"drop-in" fuel for military jets with good results. Little breeding work for yield or oil content has been done but
it offers potential as a short season biofuels crop that could fit into many different cropping systems in Florida.
No data are available on the impact of residual herbicides on camelina grown after harvest of peanut, cotton, or
other row crops. Information will be provided as we learn more about production management and markets.

Forages Dr. Yoana Newman, Extension Forage Specialist

Grazing of Winter Annual Forages
Target the stubble height to start
grazing of winter annuals not
earlier than 6 to 8 inches tall.

Winter annuals that are grazed too
early, at 4 inches, will fail to
persist or provide adequate
forage. The grazing or utilization
of winter annuals should start
when plants have reach 6 to 8
inch and livestock should be
removed when plants have 3 to 4
inches of growth remaining.

Leaving a stubble height of 3 to 4
inches will maintain enough leaf
area to generate the new leaf If winter annual is barely reaching the grazing height growth, do a light grazing and remove ani-
g growth and recover from grazing mals when at 3 to 4 inches. Photo by Yoana Newman
If grazed too early, the subsequent growth is not abundant and forage yield will be substantially reduced.

Freeze, Sorghum and Prussic Acid
In sorghums there is the potential for
prussicc acid' poisoning to cattle for a
short period of time after frosts. Prusic
acid or hydrocyanic acid is a toxic
compound that is released in plants in the
sorghum family when the plant is
affected mainly by freeze or drought.

Plants are more likely to produce prussic
acid in soil that is high in nitrogen but
poor in phosphorus and potassium.

Hay maybe unsafe if cut under drought or
after a freeze. BUT, in time, the toxic
compounds gradually volatilize, and
danger may only occur if hay is not cured

Because the prussic acid volatilizes, Sorghum field with signs of freeze damage. Photo by Yoana Newman
allow 7 to 10 days to pass before grazing
after a light frost. Do not graze plants that are wilted or plants with young regrowth. If ensiling material that
has been frosted, allow fermentation to occur for six to eight weeks before feeding.

to eight weeks before feeding.

Weed Science Dr. Jason Ferrell, Extension Weed Specialist

Florida Granted 240 Label for Wick-Bar Applications of Gramoxone Inteon

Palmer amaranth populations that are resistant to Cadre herbicide (imazapic) have become more common and problematic in Florida.
Without Cadre, the only postemergence herbicide option for Palmer amaranth control is Cobra or Ultra Blazer both of which only work
effectively if weeds are 3" tall or less. But late-
season Palmer amaranth escapes can reach heights of
over 6', drop millions of seed, and greatly complicate
peanut harvest. Hand-removal crews have been
frequently used in these situations since no herbicide
options were available. But recent research has
shown that Gramoxone Inteon (50% solution) can
effectively control these large plants when applied
through a selective-wiper system. Based on these
data, a petition was sent to the Florida Department of
Agriculture to approve a 24C label (Special Local
Needs) and the request was granted on November 8,

Wiper-type applicators are notoriously difficult to
adjust. Either the system is too loose and the
herbicide drips onto the crop causing considerable
injury, or they are too tight and not enough herbicide Figure 1: Rope-wick
is transferred onto the weeds. Due to this dilemma,
rope-wick (or gravity flow, Figure 1) applicators action printable&fid=67&tid=57644
generally are less effective and have been shown to
provide approximately 60% control of Palmer
amaranth. This is because it is difficult to transfer
sufficient herbicide solution to the weeds without
having leaks in the system. This can be partially
overcome by wiping the weeds in two directions (two
passes through the field) and driving less than 5
MPH. A more effective solution to this problem is to
use a rotating wiper which has been shown to provide
over 90% control (Figure 2). Since the application -
surface is constantly rotating, more herbicide solution .-
can be applied before dripping occurs. The wetter the
surface, the more herbicide is transferred to the weeds
and greater control is observed. But regardless of
which system is chosen, it is essential to spend
considerable time adjusting the flow on your wiper in
order for this system to work properly without
dripping. It is also important to remember that dense
weed patches can quickly dry out either wiper system.
In dense patches, you will need to either increase the
herbicide flow on the wiper, slow down, or both.
Figure 2: Rotating wiper. lhtip
This 24C label is a great addition for management of hlup %% Wild radish at bolt, reduces herbicide
Cadre-resistant Palmer amaranth. However, wipers control by 50%.
should NOT be relied upon as part of your overall *The use orFluo images is not an endorsement ofa single product, but rather an example
weed management program. For these wipers to be of two ditthrent utt1% ofapplication technology. Many manufactures and many diftferent
effective, the weeds need to be considerably taller
than the crop. As this occurs, considerable yield loss
will be expected. A full weed control program should be employed to manage Palmer amaranth every season in order to maximize yield,
but we now have the means of "rescue" a field if the need arises.


Pesticides Dr. Fred Fishel, Pesticide Information Director

New Core Manual for -_ M
Pesticide Applicators Now E._.......

Practically all applicators of restricted use pesticides
must successfully pass the Core exam in order to
become certified prior to being issued a license by .m
FDACS. The 50-question Core exam is based upon
the contents of the study manual SM 1, "Applying
Pesticides Correctly." The recently-released 7th edition
is formatted into 9 chapters along with an appendix
containing useful information for handlers of
pesticides. The 180-page manual is illustrated with full
-color photographs and costs $20. It may be obtained
through the UF/IFAS Extension Bookstore by calling
(352) 392-1764, toll-free (800) 226-1764, or online at

Dr. Fred Fishel, Pesticide Information Director
Dr. Jason Ferrell, Extension Weed Specialist

New Drift Management Guide

A 17-page illustrated guide by F. M. Fishel and J. A. Ferrell, -
provides common-sense solutions for minimizing potential
drift problems and was recently published by the UF
Department of Agronomy. The guide presents an overview of
the problem, describes types of pesticide drift, and the factors
that influence it understanding droplet size and how
equipment setup affects it, are a major point of discussion.
"Managing Pesticide Drift," UF/IFAS EDIS Document PI232, may be accessed at

it, are a major point of discussion.
"Managing Pesticide Drift," UF/IFAS EDIS Document P1232, may be accessed at


To follow the link, press "Ctrl" and put cursor over link, and "click."

Dec. 16-17
Jan. 8-10

Jan. 20
Feb. 6-8

Drip Irrigation School, Live Oak (North Florida REC)
Ag Connect Expo. Atlanta, Georgia. For more information, please check
UF/IFAS Cattlemen's Institute and Allied Trade Show, Kissimmee
American Society of Agronomy (ASA) Southern branch meeting,
Corpus Christi, TX.



New Year Wishes ...
... from the Agronomy Department...

9Happiness and Joy, and the (Best of Everything...
... That 'You So Wel(Deserved?!

Happy holidayss!


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