Table of Contents

Agronomy notes
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00066352/00100
 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: June 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: UF00066352:00100


This item has the following downloads:

May2008 ( PDF )

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

Volume 32:5 May 2008

Features .....

Legumes-An Option to Hijgh Fertilizer Prices ............ Page 2
Head Smut on Oats and Wheat ............................................ Page 3
Chilling hours or Vernalization of Wheat ........................ Page 4
Perennial I '' anu!
I'lhi 1tl FIorage Extension
Agronom Soybeans
I Soybean Seed Supplies .................................. .....................Page 4

Weed Control
Early Season Nutsedge Control in Cotton ......................Page 5
Top Pesticide Blunders....................... ........................ Page 6

M miscellaneous
Calendar Dates ...........................Page 3

Upcoming Field Days
West Florida REC, Jay, FL, Thurs., May 22
To register www.miltongators.com or call (850) 983-5216 X 113

An example of intrl1 i rp storage of
pesticides that could cause hhindersv
l\ t a t I'F. ll ui l i')
Phit lri on this pilge' Fred Fishel


In times when Nitrogen fertilizers and fertilizers in general are escalating in an almost vertical trend, the
idea of using forage legumes is an attractive and almost necessary proposition. Forage legumes. if
harvested and allowed some growth for later use as cover crops, function as a slow release fertilizer.
They may partially substitute chemical fertilizer use and may also sustain/enhance soil organic matter
content. Their use is beneficial for many Florida soils, especially for sandy soils which typical) have
low natural soil fertility, do not retain much water or nutrients, and are often prone to excessive nutrient
leaching losses.

How much Nitrogen Do they Fix?
And When Is the Nitrogen Available?

Legumes have the ability to associate x\ ith certain soil bacteria (rhizobia) that fix atmospheric nitrogen.
They may add between 20 to 150 lbs N/acre per season (see table below), depending on the legume type
growing conditions and symbiotic N-fixing bacteria present in the soil. Their herbage also tends to be
richer in proteins with no nitrates, and decomposition is more rapid compared to grass'grain crops.
Legumes when used as green manure decomposes rapidly when incorporated with moist soil. N ilrogen i
available after decomposition in four to six weeks depending on weathering conditions, in hot summer
rainy conditions it may be even less than four weeks. Nutrients released should be used immediately by
tie planted crop or warm-season grass, or it will be lost to leaching or escaping in the air as gas.

Legume Yield Biomass Yield N Seeding rate S g
Legume ,Seeding Date
L m (lbs/acre) (lbs/acre) (lbs/acre)
Annual Summer
Aeschynomene 20001 4000 50-100 6-8 Mar. I June 3(
Alyce clover 1500-3500 20-65 15-20 Mar. 1 June 30
Cowpeas 2000 4500 50-90 6-82 Mar. 1 June 30
Hairy Indigo 4500-9000 80-150 6- 10 Mar. I July 15
Vel\ ctbcans 2200 4000 50-5 30-50 Mar. I June 30
Perennial Summer
Rhizoma Peanut 2000-)6000( 8( 0-100' (bs. Jan. 15 Nlarch I5 and
(living mulch) (12-mont hs) rhizomes) July
Annual Winter
Crimson Clover 1500-4500 35-120 30-45 Oct. 1 Nov. 15
Hairy Vetch 1500-5500 35-150 20-30 Oct. 1 -Nov. 15
Lupine 21000-4500 45-120 30-45 Oct. I Nov. 15
Red Clover _

Dr. Yoana Newman
Forage Specialist
ycnew(i) ufl.edu

Agronomy Notes Pag


*1 There were many calls about head smut on oats and wheat this year.
Smut is mainly a problem on small grains if they are taken out of a bin
and planted without seed treatment of fungicides. Once heads start to
emerge and you see sniut, it is too late for treatment. Fungicides ap-
plied at flag leaf on wheat will have little impact on smut. In most
, cases only a low percentage of the heads are affected and it may lead to
lower quality hay or off- flat r forage but does not produce toxic com-
pounds. Be aware of seed stored in the bin that had a fairly high per-
centagc of smut when taken out of the bin for next year's planting since
it % ill have more smut if seeds are not treated prior to planting

The gravish heads on these oats indicate smut.
Photo: David Wright and J. Marios

Dr. David Wright, Extension Agronomist
North Florida REC, Quincy,
'-rvLll a ull cldu

Upcoming Field Days

May 22 e\ st Florida REC, Jay, FL
8:30am 3-00 pm, Prcrcgistration by 5/19 $25 i
Topics include: Herbicides and weed control; N;
Managing Bobwhite Quail
For more information: htp: "crcc. ithf.utl.cdu or

Professional Society Meetings

May 12-14 Southern Pasture and Forage Crops Improve
Kno\ville, TN
June 1-4 Florida State Horticultural Society and Crop
Society of Florida Meeting. Marriott North, Ft.
Visit ~s rl'ih ,- or call Eric Simonne. at (352) 392-19

June 17 19 211008 Florida Cattleman's Association Convei
Marco Island, FL
July 7-11 2008 American Society of Animal Sciences an
Dairy Science Annual Meeting. Indianapolis,
July 13-17 Caribbean Food Crops Society Meeting.
Miami, FL ~ Hosted by UF/IFAS
July 13-15 Southern Peanut Growers Conference
Edgewatcr Beach Resort. Panama City Beach, F

includes catered lunch
native Plants Shrubh: and

call (561) 993-4702

ment Conference

Lauderdale, FL
28, cxt. 2(1I for information.

id American Society of


Agronomy Notes Pa

Soybean acreage is expected to double or triple in Florida in 2l008. Across the U.S. acreage is
expected to increase by more than 10%. This demand has caused short seed supply of varieties that
have been tested in the region. Variety tests eliminate varieties that do not perform well. Growing
untested varieties can lead to problems x ith diseases, nematodes or other factors that result in poor
pcrlirmance. However, if growers find that the% have to grom varieties that have not been tested in
the south, they should consider maturity groups l'rum late 4 through group 8. The optimum planting
date for soybean is May 15 to June 15. Soybeans can be planted earlier and later than this date but
yields are usually lower and there may be more pest problems.

Dr. David Wright. Extension Agronomisi
Norlh Florida RFC, Quincy, wright(aufl.edu

Chilling hours



of Wheat

Wheat varieties need a certain amount of
chilling hours to head out or flower.
F leading of some varieties is also
influenced by photoperiod. The number
of hours below 50 degrees F is critical for
all varieties, however, it varies greatly
pril II Wheat varieties that have different levels rf chillinel requirements Some depending on where the variety was
are headed out and some never will. The fron plot with short wheat (see a'ow) i. developed. The farther the variety is
wheat that is not vernalized or headed out. 'hur, David 1rihti grown, from where it was de eloped, the
less likely it will respond as expected.
Many wheat varieties are bred north of Florida and require a longer vernalization period to flower.
It is important to plant those varieties early. Our normal recommended planting date for wheat for
grain in Florida is November 15 to December 15. Varieties requiring high chilling hours should be
planted in the first part of the planting season. Plant only early mnaturing wheat varieties in mid
December and do not plant any variety after that date for grain. Most adapted wheat varieties will
head out during the last days of lMarcIh or the first week of April. Varieties that head out in Mid
April are filling the head in hot %% father and the test weight will normally be low as well as yield.

Dr. David Wright. Extension A,\gonoinikt
North Florida REC, Qulinc). wrighti utl.edu


Dr. Ron Barnell,
Profesor Emeritus Small Grain Breeding

Agronomy NotesPa



Berry/Vegetable Time April newsletter is now available on-line at http://
stlira therr\ itas.ut1i idu Bern) I lines 21)(\S 3 \'"[Tili 1S.pd ['.Features include:

Late Tomato Blight Drip fumigation Crop Termination
Open Burning of Plasticulture in Hillsborough County
UF/IFAS Gulf Coast Reseurch and Education Center
Wimauma. FL

Nutsedge is one of the most common weeds across the Southeast. This weed is particularly
troublesome in cotton since it establishes early in the season. However, there are no effective
preemergence or early postemergence herbicides to control nutsedge. Gli phosale, at 0.75 lb ae/A will
commonly provide only 70 to 80"o control. A glypho-sate MSMA combination is highly effective, but
MSMA has recently been refused re-regislration by EPA. The implications are that when existing
stocks ofMSMA are exhausted, this herbicide will no longer be available. Envoke is a
postemcrgence herbicide that has proven to be extremely effective on nutsedge, but Envoke cannot
be applied before cotton reaches the 5-leaf stage of growth or severe cotton injury %\ ill result.
If nutsedge is control is necessary prior to cotton reaching the 5-leaf stage, a two-shot herbicide
program will be required. In this situation, the best solution is to spray glyphosate first which will kill
smaller nutsedge plants and essentially stop larger plants from grow ing for a period of several days.
The gl phloate will hold the nutsedge "in check" while the cotton continues to grow. After cotton
reaches the 5-leaf stage, Envoke can then be applied.
It is important to note that the glyphosate and Envoke applications should be separated by at least one
to two weeks. Control with Envoke may be reduced if applied to nutsedge that is still injured (not
actively growing) due to the glyphosate application.
Dr. Jason Ferrell
Extension Weed Specialist


" \L' r,[inli Notes" is prepared by: J.M. Bennett, Chairman and Yoana Newman, Extension
Forage Specialist (eiitw .la uil eCdui. J.A. Ferrell, Extension Agronomist 11.irerrell, 11 .i, ll1 c ll
F.M. Fishel, Pesticiide Cwrdinator Q ekldr.a I11.i ull ed.l. Clyde Fraisse. Extension Forage
pecLiali-I (d riell cr ull cilul. Brent Sellers, Extension Weed Scientist i liehllerLi. util e.l i. and
D.L Wright, Extension Agronomist i .t,, I.I ti. ull.clu) Designed by Cynthia I ligln
(I. Illrc1..i uil rldu I The use of trade names does not constitute a guaranlee or warrant of products
named and does not ,irint:, approval to the exclusion of similar products.

L inks

On occasion, accidents and problems associated with pesticide use in Florida are reported to the PIO.
Accidents are going to happen, but these reports from California top anything that we have heard.
According to the California Department of Pesticide Regulation's Illness Database, the following
selected blunders were reported during 2000-07.

SWhen Orange County residents complained of a raccoon problem, a friend overseas sent
them a bluck, granular pesticide. The wife mixed it with meat as bait for raccoons. The
raccoons did not cat it, so she labeled and froze the meatballs. Some time later, her husband
cooked and ate the meatballs. He became seriously ill and drove to a hospital
(Suspected pesticide-poisoning victims should never drive themselves to treatment, since they may
be impaired by the toxin). This victim survived both his mistakes. Later analysis of the pesticide
showed that it was nine percent aldicarb, a highly toxic insecticide: one teaspoon of the pure
ingredient could kill five healthy adults.

SIn Los Angeles County, a woman put some insecticide into a soft drink bottle and gave it to
her sister to take home. The sister left the bottle on a table, where her husband and four-year-
old daughter drank from it. They recognized their mistake and made themselves vomit before
going to an emergency room; both recovered (However, some liquid pesticides pose a risk to
the lungs from induced vomiting. Pesticide labels provide treatment instructions, but these victims
did not have a labeled container. Fortunately, they had no further health problems from their pesticide

In San Joaquin County, an apartment dweller set off a "bug bomb" sitting on top of his ,ga
stove. When the aerosol came in contact with the stove's pilot light, the resulting blast blew
out the apartment's windows, pushed out walls and raised the roof. A neighbor's windows
also blew out, according to firefighters who responded to the scene. "Bug bombs" should
never be used in any structure until all ignition sources, including gas pilot lights are turned off.

A Monterey County apartment resident poured three cleaning products into a toilet bowl an
inappropriate mix, and then left the bathroom, and returned a short time later. When she
entered the room, she inhaled the vapors from the chemical react ion, began to experience
breathing problems, and had to call 911 for assistance.

The moral of all of these blunders is thlt pesticide label directions must be read and followed. All of
these accidents could have been prevented; and fortunately, the outcomes were not fatal.

Dr. Fred Fishel
Pesticide Information Officer
\ ccd d rl'( i f u tl.ed u

The Institute of Food and .\Ar iculilr;,l Sciences (IF \SI is an Equal Employment Opportunity-
Aflirmalive 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. AgronomyNotePag
I------- I