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: September 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: VID00116
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

Agronomy Notes

Volume 33:9


Late Boll Set on Cotton ..................................................... Page 2
Replacing DPL 555 With Bollgard II ....................................... Page 2

The New Turf Block: Dwarf Bahiagrass and
Novel Perennial Peanut ........................................................ Page 3
Fall and Coping with Pasture Mole Crickets ........................ Page 4


Late Planted Soybeans ........................................................ Page 3

Weed Control

Operation Cleansweep Pickup Request ....................................Page 5
Herbicide Resistance ........................................................... Page 6


Calendar & Field Days ................................... .......................Page 7

September 2009

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.

Cotton sets fruit over an eight week period normally. If cotton is planted timely in late April or early
May, it will begin blooming near July 1 through the end of August. Almost 3/4 of the yield is from bolls
set during the first three weeks in the first and second position along the main stem. Management of
cotton for late season bolls is often not a good decision as they often contribute less than 5% of the yield
and jeopardize the remainder of the crop. Bolls on the upper nodes seldom mature if they bloom after
early September and contribute little to the total weight of the cotton crop.

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

Replacing OPL555 With Bollgard II

Expiration of DPL 555 Cotton and Transition to Bollgard II

DPL 555 cotton has been grown on about 90-95% of Florida acreage over the past several years. It is a
one protein Bt gene cotton called Bollgard and is to be replaced by Bollgard II (two Bt protein) cotton
after this season.

= This gives the cotton less likelihood of getting insect resistance to the Bt proteins than a single
= All Bollgard cotton has to be purchased by the expiration date (for original Bollgard) of
September 30, 2009 and can be planted in the 2010 season.
= Seed treatment will be applied by DP&L and will be their standard seed treatment.
= All seed will be sold in 250,000 seed count bags only.
= Seeds will be shipped by February 28, 2010 and all seed sales are final.
= Growers will be invoiced $25/bag for seed cost at time of purchase and trait fees will be invoiced
in July of 2010.
= Price of the technology will be flat with 2009 for the BGR technology in DPL 555. There will be
no credit or returns.
= There will be a replant provision but it will be with BGII variety if a replant is needed.

There is currently about 24% of the amount planted for the last several years of DPL555 seed available
for 2010. Seed supplies will be tight and will be on a first come, first served basis as I understand it.
There will be no restrictions on how much an individual grower can get except supplies are limited.

Any unplanted BG seed in 2010 must be returned to Monsanto
or destroyed including partial bags.

If there are any updates to this, we will try to get this information out before the end of September.

Dr. David Wright Aooo
Agronomy Notes Pq

Many growers planted soybeans late this year due to weather. These soybeans
should be scouted closely for insects and diseases. Most of the late planted
soybeans will be subject to being infected with Asian soybean rust since it has
Seen identified in most counties across the panhandle. Consider a preventive
fungicide application on late planted soybeans as it gets into full bloom (R2
stage) especially if tropical storms and hot, humid conditions continue.
Normally soybeans lose about 12 bu/A yield potential for every day that
planting is delayed past June 15. However, planting in narrow rows after July
15 and having irrigation can compensate for some of that yield potential loss.
Symptoms ofAsian Soybean Rust on under- Dr. David Wright, Extension Agronomist James Marois, Extension Agronomist
neath side of the leaf Note that there are no North Florida REC, North Florida REC,
yellow halos around pustules.
Photo: D. Wright

The New Turf Block: Dwarf Bahiagrass

and Perennial Peanut

There's a new turf block at the North Florida Research & Education Center in Quincy. Environmental
friendly dwarf bahiagrass and novel perennial peanut have taken the high road at the NFREC. Gary
Knox, Cheryl Mackowiak, Ken Quesenberry, Kevin Kenworthy, and Ann Blount, along with county
faculty Clyde Smith and Doug Mayo, are collaborating on evaluating plant introductions and breeding
lines of bahiagrass and perennial peanut rhizomatouss types) for use in landscape settings and roadsides.
This is just one example of the multi-disciplinary research, education and extension activities that go on
at the center.

Reduced fertilizer costs and reduced mowing requirements are just two of
the many traits that dwarf bahiagrass and perennial peanut offer.

Ann, Ken and Kevin are establishing over 100 perennial peanut ecotypes and a dozen dwarf bahiagrass
lines at the Center. Gary will focus his efforts on the beauty and utility of these plants, while Cheryl will
address the plant nutrient and water requirements. Clyde and Doug are promoting these species through
extension work with clientele and hosting field days. In addition to agronomic and horticultural
evaluations, resident entomologists, Russ Mizell and Charlie Riddle will monitor insect species that may
be associated with these plants.

We are planning a field day and tour of the new NFREC-Quincy Turf Block next summer. This
collaboration will result in new utility turf for our Florida highways and recreational areas. It will also
provide a lucrative enterprise for our local producers. The Turf Block will soon provide another reason to
visit all that grows at the NFREC.

Dr. Ann Blount, Extension Forage Specialist
NFREC Quincy,

Agronomy Nofes Pae

Mole crickets can substantially reduce forage and hay production in pastures and hay fields in Florida by
tunneling of the sod. They feed on leaves and stems of bahiagrass but mainly on the root system. Roots
damaged by mole crickets cannot provide the necessary support and cannot take up water and nutrients to
nourish the plant, causing death of the roots and over time the affected bahiagrass stand. The most
harmful of the three pest species is the tawny mole cricket, Scapteriscus vicinus, and the notes below refer
to that species.

With the beginning of the spring, usually in March, the female insects fly while the males make tunnels
and sing to attract females. The females lay eggs in April and May. Eggs incubate for three weeks,
whereupon nymphs (which look like tiny adults but have no wings) start hatching and developing. The
nymphs feed and develop from May through early September, whereupon many of them become adults (a
few spend the winter as large nymphs). In cold weather, mole crickets become inactive deep underground,
but they will still move close to the surface and feed during warm spells.

What mole cricket pasture damage to look for in the fall?

In September, look for galleries (horizontal tunnels just below the surface), churned up soil, and patches
of yellow grass that later turns brown before completely dying--caused by the new adults and the
developing nymphs.

The only commercial control available and
recommended at this time is to treat using
beneficial nematodes (Nematac is the commercial
product from Becker Underwood) that kills pest
mole crickets. The product Nematac is best
applied subsurface using a chisel rig when the soil
is wet. (see extension publication EDIS # ENY
663/ IN413). Or, a boom sprayer may be used
when the soil is completely soaked, or during
rain. The nematodes should be applied in strips
(apply one strip, skip seven, apply one, etc.)
across a mole-cricket-infested pasture, because
the nematodes are alive and will fill in the
untreated strips in about six months.

Chisel rig to apply the beneficial neamatodes.
| Photo: H. Frank
Photo: H. FrankI A parasitic wasp called Larra bicolor that was
first released in Alachua County has now spread to almost all counties in central and northern Florida.
This wasp provides some level of free biological control of pest mole crickets wherever it occurs, and
eventually should spread everywhere in Florida. The wasp gets its energy by feeding on nectar at flowers
of certain plants. These plants include Spermacoce verticillata (shrubby false buttonweed or larraflower)
and Chamaecristafasciculata (partridge pea). Propagation of these wildflowers will benefit the wasp (see
extension EDIS publication EENY-268).

Dr. Yoana Newman
Extension Specialist Forage Management and

Dr. Howard Frank, Professor
Entomology & Nematology

Agronomy Notes Pa

1 sr


Operation Cleansweep provides for a contractor to come directly to a farm or pesticide application
business for pickup and disposal of pesticides when there is a sufficient quantity in a defined area. There
is no cost charged to those who participate in the program.

Operation Cleansweep is a mobile collection program that provides agricultural producers, nursery and
golf course operators, and pest control services a safe and economical method of disposing of cancelled,
suspended and unusable pesticides. Proper disposal can be expensive and place a regulatory burden on
small agricultural producers and companies. Operation Cleansweep offers an opportunity to avoid these
V barriers and to promote safe and environmentally sound
pesticide use, handling and disposal.

Operation Cleansweep was initiated in 1995 with the
original intent of collecting lead arsenate, a widely used
Pesticide in Florida citrus production, but banned for use by
the EPA in 1978.

During 1995, Operation Cleansweep collected
more than 70,000 pounds of lead arsenate.

Statewide surveys have identified substantial quantities of
cancelled, suspended and unusable pesticides stored
throughout Florida. Some of these materials had been in
confinement for many years and were in containers
unsuitable for proper storage.
Storage of old pesticides poses environmental and safety hazards. Some, such as chlordane and DDT, are no longer allowed to
Photo compliments ofFDACS be used. Considering these factors, a 3-year pilot program
was initiated in 1996 to collect all unused pesticides. The
program has been a success as evidenced by the participation and that to date over 1,000,000 pounds of
unused pesticides have been collected.

For more information, contact the Florida Department of Agriculture and
Consumer Services by calling 877-851-5285 or email to

Dr. Fred Fishel
Pesticide Information Director

Agronomy Notes Pa

"Agronomy Notes" is prepared by: J.M. Bennett, Chairman and Yoana Newman, Extension Forage
Specialist (; A. Blount, Extension Forage Specialist (; J. Ferrell,
Extension Weed Specialist (; F.M. Fishel, Pesticide Coordinator (;
Howard Frank, Entomology and Nematology Professor (; J. Marois, Extension
Agronomist (; 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.

At this time of year, all the herbicides for a given crop have been sprayed. But before we turn our
attention away from weed control for another year, it is important that we stop and think about the
efficacy of our spray program. In particular, we need to think about herbicide resistance.

Resistance: Palmer amaranth has been documented to be
resistant to the ALS family of chemistry (Cadre, Accent, Staple,
Strongarm, Envoke, ect.) and glyphosate. Although glyphosate and ALS
resistance has not been documented in North Florida, that does not mean
that resistant Palmer amaranth has not invaded this area. Now is an
excellent time to critically scout fields and attempt to determine the
success of your weed control program.

V pattern of existing weeds. Were all weeds controlled except
for one area in the field? Usually resistance begins with one plant. It will
drop seeds that are also resistant so failure to control "weed
islands" (see Photo 1) in the field is very indicative of the early stages of
Photo 1: All weeds are controlled except this one isolated resistance. It is also possible to bring weed seed into a field with
area. This indicates weed resistance. contaminated equipment. See if there is a pattern with the weeds heaviest
Photos: Dr. S. Culpepper, University of Georgia on one side of the field. That would be indicative of a path the picker
traveled last season.

The most obvious factor is living and dead weeds occurring in the
same area. Some weeds will not be controlled because they were not
emerged at the time of application, or maybe they were too large for the
herbicide dose to be effective. However, if you observed side by side
weeds living and dead weeds that are of similar age, chances are that
resistant weeds are present. (See Photo 2for example.)

hat to do if you suspect resistance: If
-possible, remove these plants from the field to prohibit more
resistant seed from dropping. If there are too many suspect weeds for
Photo 2: Classic example ofa mixed population of hand removal to be a reasonable option, think seriously about what crop
susceptible and resistant weeds. you can grow in this area next year. For example, if you suspect
Photo: S. Culpepper glyphosate resistance, it could be useful to rotate away from cotton or
soybeans where glyphosate is the foundation of the weed control
program. Consider corn and plan to use the maximum allowable atrazine rate (3 pints PRE followed by 2 pints
POST). If you suspect ALS resistance, rotate away from peanuts since Cadre is the principle herbicide and plan
to incorporate corn or cotton. If using cotton, a good residual herbicide program will be necessary to keep these
weeds in check.

Herbicide resistant weeds have been around for a long time and crop producers have successfully managed them.
But, it does require a greatly increased level of management. There are still several herbicides and application
options (such as spray hoods) that can help overcome these resistant weeds. But applications must be made in a
timely fashion that targets small weeds. Also, new research has indicated that Palmer amaranth cannot emerge
from a depth of greater than 2" and that seeds only remain viable in the soil for 3 years. Though we have no data
to prove this, deep tillage followed by 2 or 3 years of intense weed control may reduce Palmer amaranth pressure
in some fields.

Dr. Jason Ferrell, Weed Specialist Clyde Smith, Regional IPM Agent AgronomyNotes Jackson County

August 27 2009 Extension Farm Field Day, West Florida REC
Free to the public; registration encouraged: 850-983-5216, ext. 113.

September 8 2009 Florida Tomato Food Safety Update, Ritz-Carlton, Naples
Pre-registration is encouraged to ensure enough handouts are available.
Free admission due to the generosity and sponsorship from the
FDACS Block Grant entitled "Good Agricultural Practices Training
Grant" and the Florida Tomato Exchange.

September 15 Nutrient Management Workshop, Okeechobee County Civic Center
Contact: Patrick Hogue, or 863-763-6469

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

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

September 19 Fall Field Day and Open House, NFREC-Quincy
Free to the public compliments of ADAGE
Register online or call 850-875-7100 ext. 0

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 7 "Livin' the Country Life Land and Animal Ownership" Conference
Bert Harris Agri-Civic Center, Sebring
Sponsor: South Florida Beef-Forage Program in UF IFAS Extension
Contact: Manatee County Extension Service, Christa Kirby

November 14 Florida 4-H Centennial Gala, Jacksonville

November 15-17 Energy Conference, Orlando

February 24-26, 2010 UF Water Institute Symposium, Gainesville


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Agronomy Notes Pa,

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