Agronomy notes
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00066352/00133
 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: March 2011
Subjects / Keywords: Crops and soils -- Florida   ( lcsh )
Crop yields -- Florida   ( lcsh )
Agriculture -- Florida   ( lcsh )
Agronomy -- Florida   ( lcsh )
Genre: serial   ( sobekcm )
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.
General Note: Description based on: January 1971; title from caption.
Statement of Responsibility: Florida Cooperative Extension Service, University of Florida, Institute of Food and Agricultural Sciences.
 Record Information
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000956365
notis - AER9014
System ID: UF00066352:00133


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IFAS Extension



Corn Fii,,n,, Date.......................................... Page 5
Starter Fertilizer Use in Corn.......................... Page 5
Using Conservation T '. with Weed
Resistance ......................... ....................... Page 5

Forage Weed Control and Fertilization
Tim ing ............................. ..........................Page 3
Ryegrass Removal and Bermudagrass Growth ...Page 3

Weeds and Pesticides:
First Bermudagrass Hay Cutting - It can be
weed free ..........................................................Page 2

Farm Chemical Theft in Florida......................Page 4

Calendar ............ .........................................Page 3

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/Millie Ferrer-Chancy, Interim Dean.

"Agronomy Notes" is prepared by: Maria Gallo, Interim Chair and Y. Newman, Extension Forage Specialist ..I .. II 1.. . ..J. Ferrell, Extension Weed
Specialist II . 1i. Il.i ,!I. .1. Fred Fishel ... t .1.1 I l . !I .1.,,. Brent Sellers, Extension Weed Specialist I. II. i I. ,,I . .1,,. D. Wright, Extension
Agronomist i hl.ii, l . I.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.

W eed Science Dr. Jason Ferrell, Extension Weed Specialist
Dr. Brent Sellers, Extension Weed Specialist

First Bermudagrass Hay Cutting - It can be weed free

It is generally accepted that the first hay cutting of the year will be of lower quality due to winter weeds. But since
most of these weeds will not regrow, we allow that first cutting to be "cow hay" and wait for the second and third
cutting to be our premium "horse hay". Although this production strategy is almost universally accepted, it
doesn't have to be this way. A single, well-timed herbicide application in early spring can eliminate many of these
weeds, resulting in premium quality hay from the first cutting.
The winter weed complex can be difficult to control, depending on which species are present and their size when
spraying. The most common are Carolina geranium, henbit, fireweed (stinging nettle), little barley, cutleaf
primrose, wild radish, Virginia pepperweed, and thistles. Although these weeds are common and somewhat
difficult, there are many herbicides that can be used for effective management.
Glyphosate or Paraquat. Glyphosate or paraquat (Gramoxone Inteon, Firestorm, others) can be applied when
bermudagrass is dormant. These herbicides can be used to effectively control chickweed, little barley (or other
grass weeds), and henbit. But they will both fail to control cutleaf primrose, wild radish and thistle. Glyphosate
can now be purchased for $15/gal or less, making it a cost effective choice. It is essential that the bermudagrass be
totally dormant when the application is made. If the bermudagrass is beginning to transition from dormancy, an
application of glyphosate can greatly delay early season growth. So, depending on weed spectrum and
bermudagrass dormancy, these two herbicides can be an effective and inexpensive choice. Paraquat is a restricted
use herbicide and a pesticide license is required for purchase.
2,4-D and/or Dicamba (Banvel, others). These herbicides, used separately or together (Weedmaster, Outlaw,
others), will provide good to excellent control cutleaf primrose, Carolina geranium, as well as wild radish and
thistle if no blooms are present. These herbicides can be safely applied to bermudagrass at any stage from
dormancy to full greenup. While generally cost-effective, these herbicides may struggle to control large wild
radish, henbit, or fireweed. 2,4-D and/or dicamba can be mixed with glyphosate and many other herbicides to
increase the weed control spectrum. If used alone, a careful inventory of the weeds present should be taken to
ensure that these herbicides are the appropriate choice.
Metsulfuron. Metsulfuron is sold alone (MSM 60, Valuron, and many others) as well as in combination with
many other herbicides. The reason for including metsulfuron in many herbicide combinations is for its broad-
specturm control of many winter weeds. Metsulfuron is highly effective on wild radish, henbit, red sorrel,
Carolina geranium and others. Applied alone, it will not control little barley and will likely struggle to control
thistle. If grassy weeds are problematic, mix with glyphosate. If thistles are present, mix with GrazonNext, or 2,4
-D. Metsulfuron is now available from numerous manufactures and can often be purchased for under $20 per
ounce. Considering that the application rate for most of these winter weeds is 0.1 to 0.3 oz/A, metsulfuron is an
economical and effective herbicide choice.
Aminopyralid. Aminopyralid is sold alone (Milestone) and in combination with 2,4-D (GrazonNext) or
metsulfuron (Chaparral). Aminopyralid has been shown to control fireweed, thistle of any size, and Carolina
geranium. Applied alone, it will not control wild radish or grassy weeds, and is only marginally effective on
henbit. But when mixed with metsulfuron, it becomes a very broad-spectrum combination. Chaparral will be a
more costly than metsulfuron alone, but may be well worth the price if large thistles are present.
Weeds in the first hay cutting should no longer be seen as a fact of life. There are highly effective herbicides
available, many of which can be purchased for $8/A or less. It can be difficult to determine the exact herbicide, or
herbicide combination, for maximum control of all the weeds present. For more information, consult Weed
Management in Pastures and Rangeland (edis.ifas.ufl.edu/wg006) or contact your local County Extension Office.

Forages Dr. Yoana Newman, Extension Forage Specialist

Forage Weed Control and Fertilization Timing-
Timely cultural practices are important in promoting vigorous growth for warm-season grasses. Use the weed
control program that best fits your weed problem and budget but control weeds first. Walk your pastures to
adequately identify your weeds, and the magnitude of your weed problem. Keep in mind the popular wisdom
"smaller weeds, smaller problems...bigger weeds, bigger problems". In most situations it is easier and more
economical to control weeds at a younger stage than when they are big and 'out of control'. Use the dry conditions
present during the early spring to till the soil in preparation for forage planting-Hold on the pasture fertilization
until after the weeds have been controlled and the right soil temperatures are present. The root system of warm-
season perennial forages (like bahia- or bermudagrass) will effectively utilize the nutrients when the right
temperatures in the soil are present. Fertilize when consistent warm soil temperature are present (soil temperature
greater than 65 �F).

Ryegrass Removal and Bermudagrass Growth
Overseeding with ryegrass extends the season of forage production during late winter and spring. However, field
observations, particularly during warm winter years, have shown stand reduction and slow spring regrowth of hybrid
bermudagrass pastures and fields that had been overseeded
to ryegrass. Ryegrass produces the bulk of production
during spring, a time when bermudagrass is initiating
growth. During this time, the solid shading from actively
growing ryegrass intercepts the light needed for
photosynthesis of the warm-season grass. The shade also
prevents solar radiation to reach the soil slowing down the
warm up of the soil surface. When bermudagrass starts
breaking dormancy, the ryegrass shade cover needs to be
removed to avoid a negative impact on the spring growth.
Removal of shading can be accomplished by grazing and
keeping the stubble short or by harvesting ryegrass
frequently to allow sunlight to reach the soil. Late removal
of ryegrass will compromise the regrowth of the
bermudagrass in the spring.


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Mar. 30 47th Florida Dairy Production Conference, Gainesville, FL

May 4-6 60th Annual Florida Beef Cattle Short Course, Gainesville, FL

Jul. 3-9 Caribbean Food Crops Society meeting, Two Mile Hill, St. Michael, Barbados,.
http://www.cfcs201 1barbados.org/

Pesticides Dr. Fred Fishel, Pesticide Information Director

Farm Chemical Theft in Florida
During the past year, there have been multiple farm chemical theft occurrences in
the state. Sheriffs' Offices in Lee, Palm Beach, Martin, Hendry, and Manatee
counties have reported theft of various pesticides, fuel, and equipment from these
establishments. Apparently, all incidents involved breaking and entering into
secure facilities by individuals who are knowledgeable about the involved :
pesticides because of the types that were stolen. All of the thefts occurred after the
facilities were closed; therefore, extended surveillance during the evening hours t
around farming communities is highly recommended.

The following examples are considerations relating to chemical facility security,
though not fully inclusive, particularly to agrichemical dealers:

* Securing buildings, manufacturing facilities, storage areas and surrounding
property: its fundamental, but prevention of intrusion can include elements " * .
such as fencing or other barriers, lighting, locks, detection systems, signage, *
alarms, cameras and trained guards.
* Securing pesticide application equipment and vehicles: consider using an authorization process for persons who have
access to such equipment before their use.
* Aerial application equipment: the FBI has requested that aerial applicators be vigilant to any suspicious activity relevant
to the use, training in, or acquisition of dangerous chemicals and their application. Such activity includes, but is not
limited to, threats, unusual purchases, suspicious behavior and unusual contacts with the public.
* Protection confidential information: as businesses have grown more reliant on computers and communication
technology, the need to secure these systems has grown. Efforts to include contingency planning for power losses,
monitoring access ports, adherence to password and backup procedures, and maintaining access for authorized personnel
only should be taken into account.
* Developing procedures and policies that support security needs: even the best hardware and staffing budgets are only as
effective as the procedures and policies that control their use.
* Effective hiring and labor relations are important to obtain and retain good employees who will support and follow
safety precautions. For example, the hiring process should ensure that pesticide handlers have all requisite training
necessary to handle pesticides safely. Background checks of staff who have access to secure areas, particularly those
areas where pesticides may be stored, are also necessary.
* Inventory management policies can help limit the amount of potentially hazardous pesticides stored on site, reducing the
risks of accidental or intentional release or theft.
* Effective advance emergency response procedures can be critical. Business officials and employees need to have an
understanding of how to respond and who to contact in the case of an emergency.
* Establish a procedure for locking up the facility at the close of the business day.

Suspicious incidents should be reported immediately to your local law enforcement agency, Crime Stoppers, or your regional
FDLE office. If you have information regarding similar burglaries or have questions or comments, please contact the Central
Florida Intelligence Exchange at 407-858-3950 or at cfix(ocfl.net.

Crops Dr. David Wright, Extension Agronomist
North Florida REC, Quing wright@ufl.edu

Corn Planting Date
Florida has generally recommended a
planting date of March 1 to April 15
for corn hybrids. The planting date is
set due to pest pressure especially
insects and diseases. Before Bt corn
hybrids were available, corn planted in
May was subject to high levels of
worm pressure (fall armyworn and
corn earworm) and stinkbugs and
would tassel in about 45 days. Corn
planted in March will usually silk and
tassel in mid-May. May is normally
hot and dry resulting in stress for non-
irrigated corn. Irrigation is required
on a yearly basis to produce corn
yields of 150 bu/A or more. With .
irrigation and Bt corn, good corn
yields can be made as late as early June and has been successfully double cropped if the first crop is taken off
for silage. If the first crop is taken off for grain, high levels of inoculum from leaf rust and other diseases can
result in high disease pressure on the second crop if it is planted into the first crop residue.

Starter Fertilizer Use on Corn
Many corn hybrids respond to starter fertilizer (N, P, K and S applied near the row or 2"X2" to the side and
below the seed or N, P, and S only). Our research shows that fast, early root growth of some hybrids results
in little or no response while some hybrids have slow early root growth resulting in higher responses to starter
fertilizer in final grain yield. The grain yield response of some hybrids may be as much as 30 bu/A. With
corn at historic highs of $6.50-7.00/bu, starter fertilizer can play an important role in the total fertility
program. If fertilizer is banded at planting for the total fertilizer program besides sidedressed N, application
rates of P and K can be reduced by 30% or more without yield loss. This serves as starter fertilizer since it is
placed near the row.

Using Conservation Til//age with Weed Resistance
There are ways that conservation tillage can be used with severe weed problems such as palmer amaranth.
Deep tillage can be done immediately after harvest of a crop in the fall and a cover crop planted. Not only
will turning the ground help bury weed seed but planting into the cover crop in the spring using no-tillage will
help shade any weeds that may emerge that were not buried deeply enough in the fall. Another method is to
use residual herbicides in the cover crop or crop residue preplant followed by early post followed by late post
applications. Most growers do not use any tillage after planting anymore and hoods can be used to shield
plants from residual herbicides that would damage the crop. Conservation tillage can continue to be a part of
the farming program with adequate planning to conserve soil, fuel, and labor.