Table of Contents

Title: Agronomy Notes
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00066352/00111
 Material Information
Title: Agronomy Notes
Series Title: Agronomy Notes
Physical Description: Serial
Creator: Agronomy Department
Publisher: Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida
Publication Date: April 2009
 Record Information
Bibliographic ID: UF00066352
Volume ID: VID00111
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


This item has the following downloads:

april%20agronomy%20notes ( PDF )

Table of Contents
    Table of Contents
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
Full Text
IFAS Extension


. E

Agronomy No tes
Volume 33:4 April 2009


What is 'Teff' And Can It Grow In Florida? ........................ Page 2
Bahiagrass Target pH................... ............... ............................ Page 3
Forage Growth And Stubble Height ....................................... Page 3
Bahiagrass: Protocol For Submitting A
Plant Tissue Sample......................... ....................... Page 4

Tifguard: A Nematode Resistant Peanut Variety ...............Page 5

Weed Control
2007Pesticide Date Program's Summary Released......... Page 6
Palmer Amaranth Control:
Comparing the Preemergence Options........................Page 7
Status of Small Grain Crops ............................ ..................... Page 4
Crops That May Be Planted In Dry Weather ..................... Page 5
Calendar & Field Days ............ ...............................................Page 6


What is 'Teff' and Can it Grow in Florida?
Teff is warm-season (C4) annual bunch grass, a
species of lovegrass (Eragrostis te) that
originated in the northern highlands of Ethiopia
in northeastern Africa, in ancient times (BC).
Despite being a warm-season grass, it is best
adapted to uplands in tropical areas where
temperatures are cooler than in low lands and
range from 50 to 800F; this plant can not handle

The main use is as a cereal grain for human
consumption. It is used in African countries
because of the attractive nutrition profile of the
grain (with an excellent amino acid
composition, and lysine levels higher than
wheat or barley.) It contains no gluten and is
high in dietary fiber, iron, phosphorus, copper,
aluminum, barium, and thiamin. It has a sour
taste and is similar to millet. In Ethiopia, where
it is thought to have originated, Teff provides over 2/3 of the nutrition in that country. The economic
importance of this grass is mainly as a human food (cereal). It has been used also for environmental
purposes in erosion control in Africa.

Teff straw from threshed grains in Ethiopia is considered an excellent forage,
superior to straws from other cereal species.

In the US small acreages of Teff are grown for grain production and sold to Ethiopian restaurants. More
recently (since 2007), it has been promoted by seed companies ('Tiffany' Teff) for use as a late planted
forage in northern latitudes such as Missouri and Pennsylvania where some growers are finding it as a
mite-free alternative to timothy and orchard grass. Experimental data is being generated at those
locations and preliminary results show production of only 3 1/2 to 4 tons/acre for the season.

Although this grass has not been tested in Florida, it has been tested in Georgia, where preliminary
reports show a forage productivity of less than 1/3 of most other summer annual forages. In addition it
had very weak seedling vigor in locations as far north as Athens. There is no reason to believe that it
would be adapted to the southern most latitudes of Florida.

In summary, this grass is not recommended as a forage crop in Georgia or in Florida.

It requires latitudes where the summer season is cooler than in these southern locations. The nutritive
value of the hay is high and offers an alternative comparable to timothy and orchardgrass hay for the
horse hay market.

Dr. Yoana Newman
Forage Specialist

Agronomy Notes Pa

The updated recommendation and target pH for bahiagrass
production is now 5.5 or higher. Liming should be
recommended if soil pH test is at 5.3 or lower, in which case a
lime test should be conducted. If the lime test calls for a lime
application apply it 3 to 6 months before the growing season
comes into play. Soils should be tested for pH every 2-3 years.

Dr. Yoana Newman
Extension Forage Specialist

Different grasses have different growth forms. Some are sod types, like bahiagrass. They store the energy
reserves in thick rhizomes or underground stems right under the soil level. In these sod-type decumbentt)
grasses, tillers grow through the leaf sheath to form a sod that creeps or spreads with further development
of rhizomes and stolons, common in bermudagrass and limpograss. In addition, the growing points are
low allowing the plant to be persistent under close grazing or defoliation.

The thicker the rhizomes and the lower the bud sites, the
greater the ability of the plant to withstand lower stubble
height defoliation.

Nevertheless, within sod type grasses, there are variations. Some will
grow more upright than others (limpograss > stargrass and T-85
bermudagrass >coastal bermudagrass > bahiagrass). This is the order
to follow when managing the stubble height: higher for limpograss
compared to stargrass or Tifton 85, higher in stargrass and Tifton 85
compared to coastal, and higher in coastal compared to bahiagrass (see
table). In some cases, within a grass, there will be differences among
cultivars. For example, Tifton 9 has a more upright growth than
Pensacola or Argentine bahiagrass. Or in the case Hay Rotational Continuous
of perennial peanut, Arbrook has a more upright Grazing Grazing
growth than Florigraze. The cultivars with more Wi-sason perennial
Bahiagrass 2 3 5
upright growth are less tolerant of closer Bermudagrass (Coastal) 3 3 6
defoliation. Bermudagrass (Tifton 85) 5 5 8
Stargrass 5 5 8
Limpograss 6 10 16
Warm-season annual
This table on the right shows the minimum Pearl millet 6 10
stubble height recommended for the main forage Cool-season grasses
Annual ryegrass 3 3 4
plants in Florida based on use. Rye/oat 3 3 5
Wheat/Triticale 5 5 6
Dr. Yoana Newman Perennial peanut 4 4 6
Clovers 3 3 5
Forage Specialist White clover 1 1 3

Agronomy Nofes Pae


Status of Small Grain Crops

Old corn rows which had been ripped and starter fertilizer
applied the previous year. Small grain responds to deeper
rooting and residual fertilizer.

Wheat and small grain crops have the potential to do
well in dry conditions. There has been some powdery
mildew in fields and there are some good looking crops
in some areas and some poor looking crops in others.
Small grains do respond to deep tillage and is
especially noticeable in dry or wet years. This picture
shows small grain following a late planted corn crop.
Corn was ripped in the row and starter fertilizer applied
in the row. Small grain growth is much more vigorous
with the deeper root system in a dry year and probably
has access to some of the residual fertilizer from
previous year's corn crop.

; '&. i ."a. -UM".iSi l Dr. David Wright, Extension Agronomist
North Florida REC, Quincy, wright@ufl.edu

The new bahiagrass Phosphorus recommendations are now based on tissue and soil tests. If your soil Phosphorus
(P) test results are Medium or High, (16 ppm and above) there is no need for Tissue testing, and there will not be
any recommendation to apply P. Soil P that is medium or high shows that there is sufficient P present in the soil.

The Tissue Phosphorus test is only needed when your soil Phosphorus test results are
Low or Very Low (15 ppm and below).

Below are the different analysis that can be requested and the instructions provided by the analytical lab on how to
submit a plant tissue sample.

1. Ensure that each sample contains at least a generous handful of plant 5. When sampling suspected nuLtient-deflient plants, two samples are
material around haff a gallon). recommended; ne sample from nomial plants, and another sample from
2. Do nol sample leaves contain ]tej with soil or sprays. If all tissue is abnormalplants.
dusty or spray contaminated, wash leaves gen:y with flowirg distilled 6. Wien sampling, the plant part aid plant maturity are important actors. Be
water. sure to collect the proper plant part at the recommended time. A general rule
3. Do not sample disease-, insect-, or mechanically damaged plant tissue. of tnumb is to sample tie youngest fully mature leaves during the growth
4. Place tissue samples directy into a dean paper or cloth ba. or envelope cycle, or just prior to fruit set
Do not use plastic containers. If the plant tissue is wet or succulent, allow 7. Please do nor provide any roots along wth the sample
plant material to air dry for at least one day, before mailing.

B1 Standard Soil and Tissue Test pH, lime requirement, P, K, Ca, Mg $15.00
1 Standard Soil Test pH, lime requirement, K, Ca. Mg $7.00
and P test value only
2 pH and Lime Requirement pH and lime requirement $3.00
3 Micronutrient Test Cu, Mn, Zn $5.00

The IFAS Analytical Services Laboratory has a new Bahia Producer Soil Test Submission Form that can
be found at http://soilslab.ifas.ufl.edu/

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


Tifguard: A Nematode Resistant Peanut Variety

The release of the root-knot nematode resistant variety Tifguard in 2008 was a significant advance in managing
root-knot nematodes in peanut production. Tifguard is a USDA release and the first root-knot nematode resistant
peanut variety adapted to the southeastern US production area. The variety combines major disease resistances,
including tomato spotted wilt, and the root-knot nematode resistance gene. The nematode resistance in Tifguard is
conferred by a single dominant gene, and nematode numbers are reduced after growing this variety. The
incorporation of this resistance into adapted varieties adds a powerful tool for managing nematodes and will
significantly reduce grower costs for nematicide treatment (currently $60-100/acre). More varieties that contain
this resistance will be available in the coming years from peanut breeding programs, including a number of
releases from our Florida breeding program. In the meantime, growers who have nematode problems may want to
test this new nematode resistance in their fields. Our data from a 2008 field trial using nematode resistant Tifguard
and four other non-resistant varieties are shown below. Data show a range of reactions of these varieties to the
peanut root-knot nematode (Jim Rich, Barry Tillman, Melvin Barber, and Wayne Branch)
Variety Root-Knot /100 cm3 Yield
soil at-harvest in lbs/A
Tifguard (R) 99 a** 4562 a
AP-3 (T) 178 bc 3423 b
Florida 07 (T) 120 ab 3197 b
York (I) 237 c 2085 c
GA Green (I) 163 abc 1175 d
*R = resistant, T = tolerant, I = intolerant
**Column means followed by the same letter are not significantly different (P<0.05).

Dr. Jimmy R. Rich, Nematology Specialist
North Florida REC, Quincy, jimmyr@ufl.edu

Price aside, What Crops Can We Plant in Dry Weather? Row crop farmers without irrigation face a dilemma this
year with extremely dry conditions. Not only is surface soil moisture limited but so is subsoil moisture in much of
the state. The best dry land crops for our area are cotton and peanut. Cotton is at a disadvantage at planting since it
has to be planted no more than 1 /4 inch deep. Once it gets established, it is a deep rooted crop that can withstand
extended periods of drought and still produce good yields if there is rain at some time during the bloom period of
July and August (typically rainy months). Getting a stand of cotton by early June is critical.

Peanuts, on the other hand, can be planted deep (even as much as 3 inches), a depth at where there is often
moisture for germination. Peanuts need good moisture in the pegging period which corresponds to late summer
that often brings afternoon showers. Prices are not good for either of these crops at this time; however, they may
have more profit potential than a non irrigated crop of corn or soybean.

Soybean may be the third choice since the critical period of moisture for this crop is during the reproductive period
which corresponds to August and September for most maturity groups. Weather conditions may change by that
time resulting in a good crop.

Corn may be a problem for those areas that have not had adequate rain up to now (end of March). The western
counties of the panhandle have had decent rain in the last few weeks and may be OK with corn on the heavier

Dr. David Wright, Extension Agronomist
North Florida REC, Quincy, wright@ufl.edu
Agronomy Notes



Sno tolerance established.

Since the PDP's establishment by the USDA in 1991, a wide range of commodities in the U.S. food
supply have been tested. Stringent statistical and laboratory procedures have been used by the PDP to
test fresh and processed fruit and vegetables, grains and grain products, milk and dairy products, beef,
pork, poultry, corn syrup products, honey, pear juice concentrate, almonds, barley, oats, rice, peanut
butter, bottled water, groundwater, and treated and untreated drinking water for pesticide residues.
PDP data are essential for the implementation of the 1996 Food Quality Protection Act that directs the
Secretary of Agriculture to collect pesticide residue data on foods that are highly consumed by infants
and children. The EPA uses PDP data as a critical component for dietary assessments of pesticide
exposure. Results provide realistic exposure information to the EPA assessment process.

PDP cooperates with State agencies for responsible sample collection and analysis. During 2007, 12
states participated in the program, representing all regions of the U.S. and over half of the U.S.

More information about PDP and the full report may be reviewed at http://www.ams.usda.gov/pdp.

Dr. Fred Fishel
Pesticide Information Director

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.

Agronomy Notes Pa

The most recent Pesticide Data Program's (PDP) annual
summary was published for data collected during 2007. These
data continue to demonstrate that the food supply in the U.S. is
among the safest in the world.

PDP analyzed 11,683 samples of fresh and processed food
commodities in 2007. Overall, the percent of residues detected
was 1.9%. More than 99% of the samples analyzed did not
contain residues above the tolerances established by the U.S.
Environmental Protection Agency (EPA) and 96.7% of the
samples analyzed did not contain residues for pesticides that had

"Agronomy Notes" is prepared by: J.M. Bennett, Chairman and Yoana Newman, Extension Forage
Specialist ( i .,c ., i!11 .h.lii J. Ferrell, Extension Weed Specialist (jferrell@ufl.edu); F.M. Fishel,
Pesticide Coordinator (weeddr@ifas.ufl.edu); J. Rich, Nematology Specialist (i,1111i i ,ll i... 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.

4 II' All I dI III dI* e *ds

Palmer amaranth is becoming an increasingly common and troublesome weed in the southeast. With its rapid
growth rate and enormous capacity to produce seed, this weed can go from limited to severe infestation in one or
two seasons.

Several herbicides have activity on Palmer amaranth, but season-long control can still be tricky. The millions of
seeds produced will germinate throughout the entire growing season. It has been observed that, "a new flush of
seedlings will come after every rainfall." But generally speaking, Cadre is highly effective, easy to apply,
controls small and large plants alike. However, every year brings new reports of Palmer amaranth resistance to
Cadre. With the loss of Cadre, we will be forced to rely on preemergence herbicides such as Valor and Dual
Magnum or early postemergence contact herbicides such as Cobra or Ultra Blazer. Though Cobra and Ultra
Blazer are effective options, they must be applied to Palmer amaranth that is approximately 2 inches in height
for reliable control. Considering that these herbicides have no residual activity, and must be applied within a
narrow window of effectiveness, it is imperative that we document which preemergence herbicides are most
effective. Additionally, we also need to understand approximately how long each of the preemergence herbicides
will likely last so we can better plan our postemergence application.
U The herbicides listed in Tnhle 1 (see

left) were all applied the day after
peanut planting. After the
applications were made, we visited
the treated areas weekly and counted
how many weeds were present in
each plot. We considered that each
herbicide had lost its effectiveness
when the Palmer amaranth population
reached 1 plant per 3 feet of peanut
row. We set this threshold since that
is when we considered that a
postemergence herbicide application
would be necessary.

We found that the effectiveness of
different preemergence herbicides on

Palmer amaranth control can vary
greatly. Prowl H20 and Solicam were the least effective with control ranging between just a few days and
approximately 1 week. Dual Magnum was better with 3 to 4 weeks of control, but Valor provided control for up
to 2 months. We also found that the rye cover crop at this location did little to suppress Palmer amaranth growth.
However, the rye at this location was relatively thin. Other research has shown that dense rye cover can greatly
enhance weed control.

Prowl H20 is highly effective on annual grasses, Florida pusley, and many of the pigweed species. However, we
have observed over the past several years that it is largely ineffective against Palmer amaranth. Therefore, if
Prowl H20 is the only preemergence herbicide in the program, plan to treat for Palmer amaranth escapes within
the first week after planting. Conversely, Valor will generally provide excellent preemergence control, while
also being somewhat cheaper to apply than Dual Magnum.

But for all preemergence herbicides it is important to remember that rainfall or irrigation within 7 to 10 days
after application is essential to activate the herbicide. We had excellent incorporation at this location, but
prolonged drought will likely result in each of these products totally failing to control Palmer amaranth.

Dr. Jason Ferrell, Weed Specialist

Michael Dobrow AgronomyNoes
UF IFAS Agronomy MS Candidate

Table 1. Length of time each herbicide provided satisfactory control of Palmer amaranth.

Duration of Palmer Amaranth Control*
(in days)
Herbicide Rate Rye cover No cover
Prowl H20 2 pt/A 4 2
Solicam 1.5 lb/A 11 8
Dual Magnum 1.33 pt/A 20 28
Valor 3 oz/A 60 >60
None 2 1

*Duration of control refers to the length of time (in days) that each herbicide held
Palmer amaranth populations below 1 plant per 3 feet of row.


April 4

April 16

April 21

April 29-May 1

May 4-7

May 16-19

May 22

May 24-28

June 7-9

June 7-10

July 13-15

July 20-24

July 22-23

Sept. 22-24

".... ... , ,. i . . 1 i i i... 11 A ,.

Performance Horse Short Course, Okeechobee Agri-Civic Center
For those who use their horse for ranch work or competitive events.
8:30am 3:00pm. (863) 674-4092 or horsel@,ufl.edu

Cattle and Forage Field Day, Ona, FL
UF Range Cattle REC, 863-735-1314, ext. 201

IFAS CEU Day to earn pesticide applicator CEUs
UF Campus G001 McCarty Hall, Gainesville, FL, (352) 392-4721
Host polycom sites for the event: Everglades REC (Belle Glade); Gulf
Coast REC (Balm); North FL REC (Quincy)

Florida Beef Cattle Short Course. Hilton UF Conference Center,
Gainesville, FL

UF Aquatic Weed Control Short Course, Coral Springs, FL

Florida Phytopathological Society Meeting, Orlando, FL

Digital Soil Mapping and Monitoring lecture
UF IFAS Soil and Water Science's Distinguished Seminar,
UF Campus J. Wayne Reitz Union 282, 10 11:00 a.m.
Featuring: Dr. Alex B. McBratney, University of Sydney Australia

AIAEE Conference, InterContinental San Juan Resort, Puerto Rico

FSHS and SCSSF Meeting, Jacksonville, FL

Meeting: In Vitro Biology, Charleston, SC

Short Course: Applications & Analyses of Mycorrhizal Associations
Information or registration call (352) 392-1951 email: aaag@(ufl.edu

National Conference on Ecosystem Restoration (NCER)
Los Angeles, CA

Workshop: Breeding for Resistance to Whitefly-transmitted
Viruses, Orlando, FL

Southeast Herbicide Applicator Conference Panama City Beach, FL

Agronomy Notes Pa

University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs