Table of Contents

Agronomy notes
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00066352/00104
 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: September 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.
 Record Information
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: UF00066352:00104


This item has the following downloads:

00001 ( PDF )

Table of Contents
    Table of Contents
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
Full Text

IFAS Extension


Agronomy Notes

Volume 32:9


Corn Grain Harvest ........................................................... Page 2

2008 Cotton Crop Conditions ....................... ...................... Page 3
The Art of Cotton Defoliation
Timing and Material Selection .................................... Page 3
Cotton Defoliation .............................................................. Page 4

Fall Forage Worms Early Show up .................................... Page 2
Winter Legumes this Season? ............................................ Page 3

Soybean Rust Spread

Weed Control
Applicator and Dealer License Fees to Increase ......... Page 5

Calendar of Field Days & Conferences ................................. Page 6

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.

September 2008



Corn Grain Harvest

Growers, who grow corn for grain, need to harvest as soon as the grain is dried enough. Most corn should
be taken out at 20% moisture and dried down to 12-13% while plants are standing. Tropical storms have
been playing havoc with dried down fields. Most of these fields need to be harvested to prevent further
loss from falling plants. High winds at this stage will cause great damage in many of these fields. As corn
dries weeds continue to grow resulting in more problems during the harvest operation, including the
severe weed problems in crops the following year.

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

Fall Forage Worms Early Show up
If drought conditions earlier in the year were not bad enough, the recent change to
wetter conditions seems to be favoring build up of fall forage worms. These
worms often are referred to as armywormss' but usually include both grass
loopers and the fall armyworm. The worms making their debut earlier this season
in pastures and hayfields are about 90% loopers (Moscis spp.). If scouting during
the day, both loopers and army worms tend to fall off the plants to the ground.
Each looper pupates (stage the insect undergoes in becoming a moth) by folding
blades of grass to form a cocoon, whereas armyworms pupate in the soil. You can
see the tips of the leaves turned over where the looper caterpillars pupate. The
following is a refresher on the most common insecticide treatments for pasture
and hayfield caterpillars:

Restrictions (waiting time
prior to utilization)

Maximum number of

Malathion 57% EC 2 pints per acre None No restrictions

Sevin XLR 1 to 1.5 quarts/ 14 days for hay or grazing Two (2) or less per year
Lannate LV 3/ to 3 7 days for grazing No more than 4 applica-
pints per acre 3 days for haying tions per year
Dimilin 2L 2 fl oz per acre/ No restrictions for grazing No more than 6 fl oz per
cutting 1 day for hay year. Cannot apply more
than 2 fl oz per acre/cutting
Tracer 1-3 fl oz/acre 3 days for hay or until it has
dried if grazing
*Thanks to the UF/Pesticide Information Office for their assistance on product update.

Dr. Yoana Newman
Extension Forage Specialist

Dr. Norman Leppla
Extension Entomology Specialist



Agronomy Notes Pa

2008 Cotton Crop Conditions

The Florida cotton crop is \ varied but hla a good chance ofa\ Iera in 7 o\ IC 7 lbs 'A for the first tim inl tlhe last
fet\ \cars Good rainfall since late JLun has resulteId in good growh oni most of the cotton fields The tropical
stoin l that hit in late A.-Lugst t\ isted somle of tle 'conol n II1 Iel eastern part of the panlhandlc \\ hlich \\I ll make it
more difficult to har\ cst O crall. tins has bccn a good \ car c\ccpt for carl\ planting \ hen Illoisture \\as limited
Florida growers arec looking at \areties past DP&'L 555 and arc ha\ in somein \ien ood \ iclds and liqualit
(otton delcfoliation is undlri\\ 1\ oin solllc of the clirl planctd fields and harx est \\ ll begin b\ inld September on
these fields

The Art of Cotton Defoliation Timing and Material Selection

Dcfolnation timing is often bascd on percent openl bolls. iiodcs abo\c ciacked boll (NACB) o r lat unit
accLIlllnilItioll nfticr cultout Gencrall\. once the NAC B reaches 4. or thl field is 'rca.ter than l to 71i \\lhen opln.
cotton should be defoliated to prl' cnt qualitI loss flrol \\cathcrnll or tw istcd stalks that ial occur \\ Ith tropical
storms \Wlnch dcfolilant to Lse is difficult to dletcrminc \hat \ orks in\\ oIe \ car mall not be as successful in
another l\ ear duc to \\cathcr conditions or crop cond itions. or both Harn est aic ds can be classified as ha\ i' one of
two modes of action Thcsc modes of action arc herbicidal and hormonal A tank ini\ of t \he to has a better
chance of success from \ car to \ear Herbicidal defoliants include mniatenrials such as Def. Fole\. and Aim
Hornonal t\pes include Dropp. Leafless. Finish. Harxadc and Giintar Olther hormonal t\ pes acr classified as boll
opleners and contain ethlephoii and include niaterals such as Prep and Cotton Qulk NClani g owers \\11ill use
herbicide defolants along \\ ninth a boll opener if the\ are going to han e t in 111-14 da\s /. 1 1, 1n1u, 1' .,1

Dr Da\ id \\riliht. E\tension A.lronomist
Noirt Flonrda REC. QuincL w\ lit a u t1 edu'Ll

With the increase in fuel prices, and the more favorable soil moisture conditions for most of Florida, forage
growers might look at winter legumes to cope with the costs of fertilizers and to extend the grazing season.

e Winter legumes will:
S.. I' Help lower your need for stored forages,
. .'? ~ Provide a higher forage nutritive value to the diet of your animals (compared to
o ? warm-season hay)
*.> Add nitrogen back to your pastures
-.'f *
SOne way of looking at the excess rain that Florida has received is not to focus on the down side
7 but to look at the possibilities that the extra moisture opened. The last two years were
% unfavorable for winter legumes because of the lack of soil moisture. If you are planning on
using winter legumes, there are a couple of items that need attention now. Check the soil pH, as
winter legumes require a minimum soil pH of 6.0 6.5. If your soil pH is on the low side you will need to lime.
Select legume species and cultivars adapted to Florida: crimson clover (on sandier soils), red and white clover
where you have more clay and moisture conditions. Check with your county agent to select Florida adapted
cultivars for each of these species. When overseeding, you need to reduce the warm-season grass competition in
the fall. Warm-season grasses like Bahia or Bermuda have tufted rhizomes that makes them very tough
companions. To reduce this competition, a light disking to 1 or 2 inches deep of the warm-season grass can be
done since the perennial grass will recover in the spring. If not disking or using desiccants, the time for
overseeding needs to be postponed until your night temperatures are consistently below 500F to slow the growth
of the perennial summer grass.

Yoana Newman, Extension Forage Specialist Agr y N s
ycnew@ufl.edu I Vr1


Properly defoliating cotton can be difficult. Weather conditions, cotton variety, and many other factors
can play a large role in the effectiveness of a given product.

For years, the standard for cotton defoliation has been Def + Dropp + Prep. However, new products
such as Resource and FirstPick and have been shown to be excellent defoliants. But limited research ha
been conducted in Florida with these products and more information is needed before recommendations
can be made.

Experiments were conducted on cotton planted in April (defoliated in August) and cotton planted in late
June (defoliated in October). In this experiment we found that most all of these products provided
excellent levels of defoliation. But for unknown reasons, the Def + Dropp combination desiccated and
stuck the leaves rather than properly defoliating. Additionally, none of these products adversely affected
boll opening. But the greatest differences can be seen in the amount of regrowth after the application. Ii
the August application, regrowth ranged from 11 to 32%. But in October, regrowth ranged from 25 to
58%. This was likely due to the fact that in October the cotton plant was not growing as actively, thus
decreasing the efficacy of the defoliant.

FirstPick and Resource are excellent defoliants, but were shown to consistently be the weakest for
controlling regrowth. On the other hand, the addition of Dropp consistently reduced regrowth. So what
is the perfect combination for all times? It is difficult to say. In hot weather, Def or Resource may be
your best choices. But in cooler weather, the addition of Dropp may be necessary.

August Application October Application
% defol. % boll open % regrowth % % defol. % boll open % regrowth %
Def (24 oz)T 85 90 20 93 90 45
Dropp (3.2 oz) 78 87 18 88 88 25
Def(16 oz)+ 40* 85 11 90 85 27
Dropp (3.2 oz)
FirstPick (48 oz) 85 87 32 91 88 58
Resource (8 oz) 85 87 25 92 87 50

tAll defoliant applications contained the equivalent of 24 oz of Prep.
*Def + Dropp caused 100% desiccation, but a majority of the leaves remained on the plant.
Regrowth was measured 21 days after application.

Dr. Jason Ferrell Dr. Barry Brecke, West Florida REC
Extension Weed Specialist Extension Weed Specialist
jferrell@ufl.edu bjbe@ufl.edu

"Agronomy Notes" is prepared by: J.M. Bennett, Chairman and Yoana Newman, Extension Forage
Specialist ( i !.,c i11 c...l i B. Brecke, Extension Weed Specialist (bjbe@ufl.edu); J. Ferrell, Extension
Weed Specialist (jferrell@ufl.edu); F.M. Fishel, Pesticide Coordinator (weeddr@ifas.ufl.edu); N.
Leppla, Extension Entomology Specialist (ncleppla@ufl.edu); J. Marois, Plant Pathologist
(!!.i...! ,i! ,!1 c'..In and D. Wright, Extension Agronomist (wright@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. Agronomy Noes P



Soybean rust was widespread in late August on kudzu. Tropical storm Fay probably moved spores from
down state across the panhandle with its slow move from south to west. High humidity and rainfall has-
tens the spread and spore buildup. It is expected that soybean rust will show up in many soybean fields
by the first week of September and growers should scout and be prepared to make a fungicide application
if needed. Fungicides may be applied with insecticides such as Dimilin in early September along with
boron. If weather turns dry, the disease progress will slow. Several fungicide studies have been con-
ducted on soybean rust in Florida. Most of the fungicides labeled are effective against Asian soybean
rust. Rust is usually not a problem on soybeans until they get into the reproductive stage. Fungicides
applied during R2-R3 growth stage utilizing flat fan nozzles at 30 psi appeared to do a very good job of
controlling the disease. Yield increases of 30% or more were noted on heavily infested fields and two
applications of fungicides may be needed if heavy infection is noted early, or on late planted or late ma-
turing soybeans. This is the first year since we have had the disease that we have had an extended rainy
period so the disease may progress more rapidly.

Dr. David Wright, Extension Agronomist James J. Marois, Plant Pathologist
North Florida REC, Quincy North Florida REC, Quincy
wright@ufl.edu jmarois@ufl.edu

Applicator and Dealer License Fees to Increase

As of July 9, 2008, Rule 5E-9.028 of the Florida Administrative Code was amended to increase the amount
charged for restricted use pesticide applicator and dealer license fees to the maximum amount allowed by law. The
fee increase will go into effect on September 1, 2008. The amended amounts for new licenses and the renewal of
licenses are:

Private Applicators: from $60.00 to $100.00 for a 4-year licensure period;
Public Applicators: from $60.00 to $100.00 for a 4-year licensure period.
Commercial Applicators: from $160.00 to $250.00 for a 4-year licensure period.
Dealers: from $175.00 to $250.00 for a 1-year licensure period.

A history of restricted use pesticide license fees is shown in the table.

License fee history.
Effective date Private app.* Public app.* Commercial app.* Dealer**
1975 No charge No charge $25 1st category; $10 per No charge
1979 added category
1983 $5 per category $5 per category $5 per category
1990 $30 $30 $75
1994 $35 $35 $90 $150
2002 $60 $60 $160 $175
2008 $100 $100 $250 $250

*Private, Public, and Commercial license period is 4 years, effective 1983.
**Dealer license period is 1 year, effective 1979.

Dr. Fred Fishel
Pesticide Information Officer

Agronomy Notes Pag

Sept. 8 Florida Dairy Business Conference
Marion County Extension Service, Ocala, FL
(352) 793-2728 (Russ Giesy or for dinner reservations: Jeanne)

Sept. 12 Soil and Water Science Research Forum
Gainesville, FL http://soils.ifas.ufl.edu/forum/

Sept. 16-19 International Citrus & Beverage Conference
Clearwater Beach, FL
Visit: www.conference.ifas.ufl.edu/citrus

Sept. 18 Perennial Peanut Field Day
North FL Research and Education Center, Marianna, FL

Sept. 19 NW Florida Bioenergy Conference & Expo
UF/IFAS Pensacola Junior College Milton Campus, Milton, FL
Contact: Robin Vickers (850) 983-5216 ext. 113
Email: rvickers@ufl.edu or visit: www.MiltonGators.com

Sept. 23-24 Forage Workers Field Tour
Marion County Extension office. Ocala, FL

Sept. 25 2008 Fall Field Day
North Fl Research and Education Center, Quincy, FL.
http://nfrec.ifas.ufl.edu (850) 875-7100 ext. 0

Sept. 26 llth Annual Hay and Farm Field Day
UF/IFAS NE Florida Beef and Forage Group
WW Ranch near Jacksonville, FL
Contact: Elena Toro (386) 362-2771

Oct. 14 Sunbelt Ag Expo
Moultrie, GA

Oct. 15 Pasture Weed Day
UF/IFAS Ona Range Cattle Research Center, Ona, FL
Pre-registration $20 by Sept. 30. Onsite registration $50.
Contact: Toni Wood flstroll@ufl.edu or call *863) 735-1314.

SAgronomy Notes PaP L