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Agronomy notes
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Permanent Link: http://ufdc.ufl.edu/UF00066352/00099
 Material Information
Title: Agronomy notes
Uniform Title: Agronomy notes (Gainesville, Fl.)
Physical Description: v. : ill. ; 28 cm.
Language: English
Creator: Florida Cooperative Extension Service
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida.
Place of Publication: Gainesville
Creation Date: May 2008
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 )
serial   ( sobekcm )
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.
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Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000956365
notis - AER9014
System ID: UF00066352:00099


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IFAS Extension



Dr. Kenneth Cassman visits UF
Feature on Page 6

Volume 32:4 April 2008

Special Feature: UFDepartments bring
Renown Agronomist to UF ................................. Page 6


Follow-up on Forage Potential of Edible Peanut ......... Page 2
Forages and Sulfur Fertilization....................................... Page 2
Hay, Forage, and Weather Updates for Florida ......... Page 3
Planting Forages and Minimizing Risks ........................... Page 2

Soybean Maturity Group and Planting Date ..................Page 5
Increased Soybean Acreage ...............................................Page 7
Seeding Rates for Narrow and Wide Row Soybeans...Page 8
Weed Control
Slender-leaf Goldenrod Control in Pastures ..................Page 8
Does Your Pesticide Storage Facility
M measure Up? ............. ......... .............................Page 9
Late Season Burndown in Cotton .......................................Page 10
Calendar Dates .......... ........................Page 5
Cover Crops ... ....................................................................Page 7
Sulfur Fertilization of Crops................................................Page 7
Volunteers Needed to Read on Florida Ag
Literacy Day ........................................................ Page 10

Upcoming Field Days
Everglades REC, Belle Glade, FL, Tues., April 8
For more information: http://erec.ifas.ufl.edu or call (561) 993-4702

n our March issue of Agronomy Notes, we discussed the forage potential of edible peanuts. It is
important to remind producers that many of the herbicides commonly used for edible peanut
production (Cadre, Valor, Prowl, etc), or fungicides, restrict grazing or haying the peanut vines.
We realized that some people do bale peanut vines but this is an illegal practice if they have used
pesticides that restrict feeding. Some of the newer cultivars do have levels of leaf spot and rust
resistance that would permit the successful use of peanut vine for grazing or haying without the use of
fungicide, however, weed control applications may still be required.

Dr. Yoana Newman, Dr. Jason Ferrell
Extension Forage Specialist Extension Weed Specialist
vcnew(@iufl.edu iferrell(@iufl.edu

As mentioned in the Spring weather outlook, April and May are usually too dry in Florida.
These month are not ideal for establishing pastures as they are risky for planting if in rain-
fed conditions. This year because of the predicted drier than normal conditions due to La
Nina, the risk of establishment failure seems to increase unless you have irrigation. Instead
of planting, use this dry period to prepare the field using the dry conditions to your advantage. Make
sure you do your lime application if your soil test calls for it, and do it ahead of time before starting the
land preparation. Do the planning now for summer planting; contact your seed provider, plan for
conditioning of the seed if planting vegetative material, and make arrangements toward that so you can
be ready when the summer rains start. Our somewhat unique conditions in Florida make it ideal for
summer planting (remember summer time is hurricane season, and even in dry years, it is in summer
when we receive most of the rainfall in the majority of Florida). Planting in summer time will
minimize your risk when establishing pastures if you have prepared your seed bed well and have a
weed free planting area. As much as possible plant into a moist or humid seedbed.
Dr. Yoana Newman

When planting pastures, adequate sulfur supply to the forage plant in the top soil (top 6
inches) is important because these new areas, particularly in sandy soils, are low in
organic matter and the newly established forage plant is in the process of developing a
root system and may not be able to uptake sulfur available at lower depth. Sulfur is a
secondary nutrient together with calcium and magnesium; 'secondary' meaning that these are nutrients
required in lesser amounts than the primary nutrients nitrogen, phosphorus, and potassium. Sulfur is
essential in proteins and is important for nitrogen fixation in legumes. Sulfur is mobile and in sandy
soils it tends to leach more compared to soils that have more content of clay. The suggested
recommendations for forage crops in sulfur deficient areas is to apply 5 lb per expected ton of dry
matter. If anticipating a yield of 5 tons of dry matter, the rate of sulfur to use should be about 20 to 25
lb per acre.

Dr. Yoana Newman
Extension Forage Specialist, ycnew@ufl.edu Agronomy Notes Pa

Hay, Forage, and Weather Updates for Florida

March 24, 2008
Following is an update on hay and forage production as well as weather conditions for Florida. This
update provides a perspective of where we are in pasture and hay production. There is also the
Spring weather update for strategic and critical decision making.

Drought Monitor
March 18, 2008
http://drought unl.edu/dmn


DO Abnomialy Dry
Di Olmighl Mcdarctte
U D2 Ormighl S-CE!Ir4

DA ODA I hrnijgl
DA Ornlgh, F-IT.Ophonal

North Florida

Current forage production in the North West area
is good although set back due to frost in the last
week of March. The Florida Panhandle is
gradually recovering its moisture. In this quarter
some areas have received 17 inches of rainfall.
Ponds are filled, soil moisture is replenished.
Within this context, winter forage production is
good despite the warm temperatures and the slow
start due to the dry soil conditions on which these
forages were planted. Hay prices for bahiagrass
are $40-50/round bale.
In the North East, the hay supply is good. There is
plenty of hay in the barn. Many areas in this part
of the state do not have much winter pasture
grown because the rains needed at planting were
not there. Pastures are in 'overgrazed' condition
with presence of many winter annual weeds. At
present many producers are feeding hay until
bahiagrass comes out. Hay prices for bahiagrass
in the northeast are $45-55/round bale; high

quality nay is $, 5-ou/round Dale; sc
range from $ 5.5 to 7.5/bale.

Central Florida

Central Florida winter weather has been favorable with intermittent but well distribute
allowing for adequate ryegrass production. The water table is close to ideal conditions
areas. Price of round bales in Central East Florida is $45-50 for bahiagrass, and up to $
bermudagrass hay; square bales are approx. $ 8/bale.

South Florida

South Florida remains under the influence of severe drought conditions but there seem
release with spotty rainfall events. The local hay supply has been used but there is a fa
hay brought from neighboring states. Hay prices for bahiagrass round bales in south F
-45 and $48-52 for bermudagrass.

SAgronom) *

uare Dales

d rainfall
in some
;70 for

s to be some
iir supply of
lorida are $40

/Notes Pac

Current Weather Conditions

Moderate La Nifia (colder than normal ocean temperatures along the equator in tt
Pacific Ocean) conditions that developed during this fall and winter has likely rec
and will continue at least through the month of April. La Nifia is well known to t
conditions and warmer weather to the Southeast in the colder months (November
While the threat of a dry winter did not fully materialize in the northern parts oft
counties in south Florida remain under severe (most of the southwest including C
Charlotte, Desoto, and Sarasota) or extreme (Glades, parts of Highlands) drough

Spring Weather


Spring in Florida is generally dry
due to the weakness of two
important mechanisms by which
rainfall reaches the state. The polar
jet stream rarely passes into the
Deep South causing frontal rainfall
to become less frequent than during
the winter. The other reason is that
the stable air flowing from high
pressure systems over the Atlantic 'L ~
Ocean continues during the spring
and reduces convectional and .
convergent rainfall, our main source TEMPERATURE PROBRBILITY
of summer rain. VRLrD RMJ 2008
rMADE 20 RMR 2008
Looking at historical rainfall
measurements from past La Nifia Temperature outlookforApril-May-June .,i. i,,
episodes, April generally brings a above normal temperature across most of the south
weak tendency for drier than normal
conditions over the Florida peninsula. The most recent released drought outlook
www.cpc.ncep.noaa.gov/products/expertassessment/seasondrought.gif) calls f(
persist in the southwest region of the state during the next three months. Warmer
also expected to persist through June across Florida.

Keep this forecast in mind when planning the 'planting of your pastures' and for
cultural practices on those that are already established. (For more information ch(
about 'Pasture Establishment and Minimizing Risk').

Dr. Yoana Newman Dr. Clyde Fraisse
Extension Climate Specialist Extension Forage Specialist
ycnew@ufl.edu cfraisse@ufl.edu


ie eastern and central
iched its peak intensity
typically bring drier
through March).
he state, several
ollier, Hendry, Lee,
t conditions.

i. higher chances for
hern U.S.A.

or drought conditions to
than normal weather is

implementation of
eck article on page 10

Igronomy Notes Pac

Soybean Maturity Group and Planting Date

Several years of research with group V-VIII soybean shows that the opt
soybean is early May through the second week of June. Earlier planting
result in lower soybean yield. The long juvenile soybean that was dev(
allow higher yields at early and later planting. However, even these va
yields planted during the recommended planting date of May 10 to June 15. Pla
earlier is normally better than planting a week or two later than the recommend
are more group V, VI, and VII soybean on the market than there are group VIII
were developed for the deep south and the acreage has been low in these states
many cases, group V and VI soybean will do better under rainfed conditions th
because they mature earlier and need good soil moisture during the months of
September. Group VII and VIII soybean will need good soil moisture through
October. Group V soybean will normally be ready to harvest by about October
soybean will be ready to harvest around November 7-10. The other groups will
10 days apart.

Dr. David Wri
North Florida REC

Upcoming Field Days

April 8 Everglades REC, Belle Glade, FL
For more information: http://erec.ifas.ufl.edu or c

April 11 Goat Field Day, FAMU Research & Extension
Quincy, FL For information, www.famu.edu/herds

Professional Society Meetings

May 12-14 Southern Peanut and Forage Crops Improvem
Knoxville, TN

June 1-4 Florida State Horticultural Society and Crop
Society of Florida Meeting, Marriott North, Ft.

June 17 19 2008 Florida Cattleman's Association Convenl
Marco Island, FL

July 13-17 Caribbean Food Crops Society Meeting
Miami, FL Hosted by UF/IFAS

July 13-15 Southern Peanut Growers Conference
Edgewater Beach Resort, Panama City Beach, FI

imum planting date for
g or later planting will
loped by Dr. Hinson will
rieties will have higher
nting a week or two
ed planting period. There
. The later group beans
in the last 10-15 years. In
an later group soybean
August and early
September and early
7-10 while group VIII
fall in between about 7 -

ght, Extension Agronomist
, Quincy, wright@ufl.edu

all (561) 993-4702


lent Conference

Lauderdale, FL


Agronomy Notes Pag


UF Departments bring Renown Agronomist to UF
Lecture available on-line at https://swsde.ifas.ufl edu/


were pleased to host a visit to the UF campus by Dr.
Kenneth Cassman on March 5-6. Dr. Cassman is
Professor and Director of the Nebraska Center for
Energy Sciences Research and former Head of the Department
ofAgronomy and Horticulture at the University ofNebraska.

Dr Cassman is an international leader in
agronomy and soil science, and his recent work
on the use of crops as sources of bioenergy has
gained broad attention.

During his two-day visit to campus, Dr. Cassman presented a
lecture entitled Biofuels, Global Food Security, Land-Use
Change and Greenhouse Gas Emissions and this lecture is
available on-line at the link above. Once the page is accessed,
there's no need to log on. Scroll about halfway down the page
and click on "Ken Cassman," and the video will load.

During his visit, Dr. Cassman also addressed the Graduate
Agronomy Seminar class on the topic of Trends in Crop Yield
Potential and Ecological Intensification ofAgriculture. In
addition, Dr. Cassman discussed issues related to energy
Dr. Kenneth Cassman visits UF. production, especially the production of bioenergy crops, with
Courtesy Photo: University ofNebraska about 60 students in two other courses, and met with Agronomy
and Soil and Water Department faculty and graduate students, as
well as with members of the IFAS administration. Dr. Cassman
shared considerable scientific expertise, enthusiasm, and excitement for the work he has been doing
and certainly stimulated our scientific thinking on issues associated with the rapidly expanding use of
crops for energy production.

Jerry M. Bennett, Chair and Professor
Agronomy Department
University of Florida

Agronomy Notes Pa

"Agronomy Notes" is prepared by: J.M. Bennett, Chairman and Yoana Newman, Extension
Forage Specialist ( tic ,, !1 ci...ll i J.A. Ferrell, Extension Agronomist (jaferrell@ifas.ufl.edu);
F.M. Fishel, Pesticide Coordinator (weeddr@ifas.ufl.edu); Clyde Fraisse, Extension Forage
Specialist (cfraisse@ufl.edu), Brent Sellers, Extension Weed Scientist (bsellers@ufl.edu); and
D.L. Wright, Extension Agronomist (dlw@ifas.ufl.edu). Designed by Cynthia Hight
(chight@ufl.edu.) 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.

the current price and the price of fertilizer and inputs that other crops
Seed should be purchased early to make sure that you get better variety
for the Deep South can be found on the web at www.griffin.uga.edu/s
recommended soybean varieties are already taken and varieties will h,
maturity group without a lot of information on them (Maturity Group
more to residual fertility than to direct fertilization but can respond to
testing low or very low. There are several good Roundup Ready varie
growing soybean much easier than using conventional varieties from
should be planted in rows 30"-36" apart with subsoiling in the row. M
inoculated with the proper inoculant (Rhizobium japonicum) at plantii
soybean plants can fix their own nitrogen for good plant growth and y
high yield and should not be grown in the same field more than once i

C over crops have value
in producing nitrogen
if it is a legume. All
grass and legume cover crops act as a reservoir for maintain
after they are killed. Cover crops help to increase water holding capac
up soil moisture for the crop that is to be planted behind it if it turns o
killed early enough. As the cover crop degrades it provides energy fo
carbon dioxide. Caution exchange capacity of the soil can be increase
by cover crops. It is important to kill the cover crop at least three and
advance of planting the crop. This practice helps to eliminate soil inse
drying. It is much easier to plant through dried cover crops than those(
coulters have to slice through the soil ahead of the subsoil shank.

that contain little or no sulfur. Most of the crops require 15-20 lbs/A
this amount of sulfur should be applied with nitrogen or as Potassium
magnesia or other sulfur containing fertilizers. Growers may use nitro
sulfur when applying split applications and when sidedressing the cro
sulfur from leaching along with nitrogen.

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

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

interest in soybean
this year than in the
past 10 years due to
require in greater amounts.
:ies. Soybean performance trials
wvt. However, most of the
ave to be grown for the proper
V-VII). Soybean responds
potassium applications on soils
ties on the market that make
10-12 years ago. Soybean
[ake sure the seeds are
ng to ensure that the young
ield. Good rotation is critical to
n three years.
Dr. David Wright

ning nutrients in the topsoil
ity of the soil but may also use
ut dry or if the cover crop is not
r microorganisms releasing
d and soil structure improved
preferably four or five weeks in
:cts and to keep soil from
that are wilted and tough when

Dr. David Wright

Sany of the
fertilizers that are
used today are high
analysis materials
of sulfur for best yields. At least
sulfate, sulfate of potash
gen materials that contain 3-5%
p. This practice will help keep

Agronomy Notes Pa


x, age,
ute of

Soybeans are usually grown in 36" rows by most producers and this comes from tradition of having to cultivate.
However, this is no longer the case with roundup Ready soybean. Herbicide resistant weeds are making it more
necessary to keep residual herbicides in the program. Seeding rates will be different for different row spacings.
Normally we suggest 7-9 seeds per foot of row in 36" rows which amounts to about 40-45 lbs of seed per acre de-
pending on seed size. With no-till drilled beans in 10" rows, 3-4 seeds per foot of row are required or about 65 lbs
of seed per acre. If a conventional drill is used with 7" spacing, about 2-3 seed are needed or about 75 lbs of seed
per acre. If conditions are optimal at planting a few less seed can be used but if conditions are harsh at planting
higher seeding rates are needed as well as for late plantings in July. Yields are normally highest planted in 30-36
inch rows when planting during the recommended dates of May 15-June 15 as compared to more narrow rows.
Very late plantings should have more narrow rows to take advantage of light, water, and nutrients from plants that
are smaller.
Dr. David Wright, Extension Agronomist
North Florida REC, Quincy,

Slender-leaf Goldenrod Control in Pastures

Slender-leaf goldenrod (Euthamia caroliniana), commonly called flat-top goldenrod, is found throughout
Florida. Its native range extends from Louisiana to Nova Scotia, with many different ecotypes
throughout. In Florida, this weed is found in 'older' pastures that have not been well managed and likely
have low soil pH. Many of us do not notice this weed until it begins to flower from August through
November; a point in time where an herbicide application is not beneficial.
~ Slender-leaf goldenrod is a perennial plant that spreads by both
seed as well as creeping rhizomes. Individual leaves are up to 8 cm
long and 3 to 5 mm wide with 1-5 visible veins. At maturity,
individual plants can reach heights of 3 to 4 feet. The flowers are
1 s yellow.

S'. l Control of slender-leaf goldenrod is not easy once plants have
become established in a pasture. Therefore, the first step is
prevention. Slender-leaf goldenrod prefers acidic soils; maintaining
the proper soil pH for optimum forage growth will limit infestations
of this weed. Once established, however, there are very few
herbicide options. If plants are 15 inches tall or greater, no
herbicide available for use in pasture will provide adequate control.
Slender-leaf goldenrod with yellow blooms. In fact, all the herbicides available for the pasture market did not
even injure slender-leaf goldenrod when applied at flowering. The
Photo: Brent Sellers only time control with herbicides has been successful is the early
spring when plants are beginning new growth. Apply 3 to 4 pints/
acre of WeedMaster (banvel + 2,4-D) to plants less than 15 inches tall (April to May). This application
rate should provide 80 to 95% control of this weed species.
Brent A. Sellers, Extension Weed Scientist
Range Cattle REC, Ona AgronomyNotes




Does Your Pesticide Storage Facility Measure Up?

It's one of those jobs that we say we'll get around to doing
on a rainy day cleaning up and evaluating the pesticide
storage facility. If you've ever seen a facility such as the
one shown on the left, then you know that a little effort can
save lots of future work and headaches. Anyone managing
an agricultural production firm that has had a FDACS
pesticide use inspection understands that the storage
component of the inspection is straightforward
Basically, inspectors will check for 3 items:

An example of improper storage ofpesticides. > Are restricted use pesticides stored in a
(Not at UF, of course!) secure manner? That is, are they kept under
Photos on this page: Fred Fishel lock and key with signage indicating their
presence as in the photo on the right?
: Are pesticides stored according to label directions? Are they labeled and
their containers capped?
4> Does the condition of the storage area appear not to injure or endanger

There are several simple things that can also be done to improve the logistics
of the facility. Some of these are relatively inexpensive; others cost nothing.

A facility designated as a "pesticide storage facility" should be just that only containers
holding pesticides. Paint, solvents, fuels, lubricants, PPE, tools, equipment, food, feed,
medicines, clothing, and all other such articles belong somewhere else.

Materials and cleaning supplies for the facility. Does the facility have a spill kit?
Accidents, large and small, don't keep calendars and clocks. They are a potential to
happen at any facility at any time. Spill kits are relatively simple, and contain such
items including a shovel, broom, dust pan, absorbent materials and a hazardous
materials-rated drum. Many of these items can be held in a 5-gallon drum as in the
photo on the left.
Post an Emergency Contact List. When and if an accident occurs, will you know
who to contact? An emergency contact list can be made and posted at the facility.

Materials used for keeping storage facility records. Ask yourself if you can
remember when the product arrived at the facility. If the arrival date is not
labeled on the container or package, often you will not know. A simple
notebook that lists the inventory by product and arrival date is a great and
easy way to track what comes in and out of the facility. In the photo, ours
is shown in notebook fashion attached to a shelf with the inventory. 4

If it's not a pesticide or one of those materials mentioned, then it belongs
somewhere else. You don't have to wait for the rainy day, or worse an
accident, to inspect and make any upgrades to the facility.

Dr. Fred Fishel, Pesticide Information Officer
weeddr@ifas.ufl.edu Agronomy NoesPa

The most critical time for weed control in any crop is during the first 6 to 8 weeks after emergence.
This demonstrates the importance of "starting clean" an effective preplant burndown program. The
most common weeds we encounter at this time are wild radish and cutleaf eveningprimrose. These
weeds can be easily controlled with 2,4-D, but the application must be made 30 days prior to planting
due to potential crop injury. Although 2,4-D is the least expensive option, the 30 day window is often
missed and other herbicides must be used. Below is a list of herbicides that can be used for preplant
burndown less than 30 days prior to planting.

Although these herbicides will be more expensive than 2,4-D, they can offer greater flexibility if a 2,4
-D application can not be made 30 days prior to planting

Herbicide Effectiveness on wild radish Planting delay
and cutleaf evening primrose
Clarity 8 oz/A Good to excellent on both 21 days and 1" of rainfall
Valor 1 to 2 oz Fair to good on primrose and Strip-tillage: 15 days and 1" rainfall for
good on wild radish 1 oz and 21 days for 2 oz.
Harmony Extra Fair on primrose, excellent on 14 days
0.5 oz wild radish

Dr. Jason Ferrell
Extension Weed Specialist

The Board of Directors and staff of the Florida Agriculture in the Classroom, Inc. (FAITC) invites
you to participate in Florida Agricultural Literacy Day. Florida agriculture industry volunteers are
asked to visit elementary school classrooms around the state and read a special book written for
the fifth anniversary of the event called These Florida Farms! and talk with K-5th grade students
about the importance of Florida agriculture.

These Florida Farms! by Gary Seamans of FDACS' Division of Marketing is a rhyming book in
which students learn about Florida agriculture by touring farms around the state with a safari
guide. It's readers' responsibility to schedule classroom visits. While volunteers are encouraged to
read on Ag Literacy Day (April 10) they may choose another day. However, readings should be
completed by the end of the school year, and classroom visits should be scheduled at least two
weeks in advance as some school districts may require volunteers register before they are allowed
on school grounds.

To register, either visit FAITC's website at www.agtag.org and fill out the form by Friday March
28. Once registration is received, FAITC will send a book, a lesson related to the book, classroom
sets of bookmarks and other materials.
Agronomy Notes