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Agronomy notes
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Permanent Link: http://ufdc.ufl.edu/UF00066352/00102
 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: July 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.
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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: UF00066352:00102


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Full Text

IFAS Extension

Agronomy Notes

Volume 32:7 July 2008


Corn Price Rises Should I Plant this Summer? ......... Page 2

Critical Management Decisions for Cotton..................... Page 2

Bahiagrass Seeding Rate .................................... Page 3
Perennial Peanut Hay for Horses .................. Page 3

Update of Asian Soybean Rust ........................ Page 4

Weed Control
Understanding Pesticide Label First Aid Statements
and Handling an Emergency .......................................... Page 5
Maverick Herbicide for Pastures .................................... Page 6

Calendar Dates .............................................................. Page 4

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.

Corn prices are at a historic high and going higher weekly due to the use of corn for ethanol and the
floods in the mid west. Farmers are asking if they can plant corn into July and still make a decent yield.
We have many years of research showing that corn can be planted into July if it is a Bt hybrid and if it
has good disease tolerance to the main corn diseases.

Corn seed was in short supply earlier in the year so the better hybrids may be gone. Yields are normally
reduced after the recommended planted date of February 15 to April 15. The main causes of yield
reduction are insects and diseases. Check variety trial information on hybrids grown near your farm
before you make the decision to plant that late and set a cutoff date of July 15-20 for corn planted for
grain. Length of growing season is not usually an issue until corn is planted into August and then test
weights can be reduced from filling out kernels in cold weather.

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

Critical Management Decisions for Cotton

July is a critical month for many management decisions in cotton in the Deep South. Layby application
of herbicides, N applications, controlling growth with growth regulators, and irrigating to set a good boll
load are all part of needed management decisions. Rainfall has been very erratic with some areas having
adequate rainfall and nearby areas remaining dry. Growers will have to scout each field to determine the
needs of the crop due to the spotty rains. The increase in acreage of corn and wheat has also brought an
increase in the numbers of stinkbugs and foliage feeding insects.

It will be very important to scout cotton fields that are near corn as it is drying down.

Stinkbugs will be moving out of the corn into cotton fields. Stinkbug feeding can result in boll shed at
an early stage or boll damage that can reduce picked yield by almost 100%. Likewise, those fields that
typically have had high hardlock damage can be sprayed with fungicide and insecticide during bloom on
a two week schedule to reduce the amount of hardlock. Headline has a label for controlling hardlock
but will also reduce foliar diseases in those fields that have a history of early defoliation and hardlock.
Topsin M fungicide can still be used through late July if more than two treatments of fungicides are to
be used. As with all treatments, split fields or leave check strips with and without treatments to see if
they are of benefit in your operation.

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

Agronomy Notes Pa

"Agronomy Notes" is prepared by: J.M. Bennett, Chairman and Yoana Newman, Extension Forage
Specialist (ycnew@ufl.edu); J. Ferrell, Extension Weed Specialist (jferrell@ufl.edu); F.M. Fishel,
Pesticide Coordinator (,1 c....lI.l ,, il., .ii cl..l James J. Marois, Plant Pathologist (im...! ~ cl, .ii .
and D.L. Wright, Extension Agronomist (dlw@ifas.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.

Bahiagrass Seeding Rate

How much seed should one use when planting bahiagrass? Does it matter which cultivar you use? Under
Florida sandy soil conditions, lower seeding rates of 10 to 20 lb/ac are likely to produce low stand
coverage during the first year compared with rates of 30 to 35 lb/ac. At lower seeding rates, weed
invasion is an issue specifically with cultivars like Argentine that have a more "crawling" or "flat" growth
compared to Pensacola, Tifton 9, or UF-Riata. In the case of Argentine, weeds tend to invade when lower
seeding rates are used because of the lower height of Argentine bahiagrass. The cost of a higher seeding
rate is offset by the more mechanical control you will need when using less seed. Keep in mind that
bahiagrass should not be sprayed for weed control before plants are 6 inches tall, otherwise severe
scorching will occur. A good seedbed preparation, adequate moisture, and rates between 30 to 35 lb/ac
should guarantee a good stand of bahiagrass.

Dr. Yoana Newman
Forage Specialist

Perennial Peanut Hay for Horses

Perennial peanut is a perennial warm-season legume that has
all the attributes sought-after in legume forage. Its
digestibility is similar to 'Alfalfa' with stem digestibility
shown to be equal or higher than alfalfa stems. The leaves of
perennial peanut are similar to those of edible peanut but
r smaller, also, perennial peanut will not produce the nut or
'peanut'. It is mainly all foliage, palatable to horses.

It is a very high quality feed that suits animals with
high nutrition requirements such as lactating mares
A farmer stands with a recent bale ofperennial peanut. or performance horses.
Photo: Yoana Newman
It is not for all types of animals; mature horses tend to gain
excess weight in full feeding on Perennial Peanut. Because of its richness, a note of caution is to avoid
overconsumption by horses when switching from low quality. Perennial peanut can be grown as a
monoculture or mixed with warm-season perennial grasses, in which case, just like alfalfa, the hay will be
of lower quality. If other states had Florida's climate and soil conditions, perennial peanut would be the
forage of choice and it would dethrone 'alfalfa' as the queen of forages.

Dr. Yoana Newman
Forage Specialist

Agronomy Notes Pa[

With a little more normal rainfall in 2008, soybean rust has started popping up on kudzu in north
Florida. The web site http://www.usda.gov/soybeanrust/ is devoted to rust updates and has the latest
information from all states. In the third week of June, soybean rust was found on soybeans for the
first time in 2008 in a field in Gadsden County that was being monitored for various diseases. The
disease does not normally affect soybeans until it starts blooming or later. However, the bloom
period can be within 20-40 days of planting depending on planting date, maturity group of the
soybean and environmental conditions. Counties will be notified as the disease appears in their
counties. Fungicides will control the disease and one timely fungicide is usually all that is needed if
timed correctly. Many growers apply fungicides after pods begin to form on the plants. Keep fields
scouted and apply fungicides when needed for all diseases. Most applications of fungicides are made
in late July or August, under normal circumstances, during the bloom and pod fill stages of growth.

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

July 7-11 2008 American Society of Animal Sciences and American Society of
Dairy Science Annual Meeting. Indianapolis, IN

July 14-17 Southern Regional Cooperative Soil Survey Conference
Paramount Plaza hotel & Conf Center, Gainesville, FL

July 13-17 Caribbean Food Crops Society Meeting
Miami, FL Hosted by UF/IFAS
July 13-15 Southern Peanut Growers Conference
Edgewater Beach Resort, Panama City Beach, FL

Aug. 20-21 Forage Workers
Marion County Extension Office, Ocala, FL

Oct. 14 Sunbelt Ag Expo
Moultrie, GA

Nov. 5 2008 Florida Ag Expo
Gulf Coast Research and Education Center in Balm, FL
Visit http://glafexpo.ifas.ufl.edu or call Christine Cooley (813) 634-0000 x 3101 ccooley@ufl.edu

Nov. 11-14 Methyl Bromide Alternatives Conference
Orlando, FL, http://mbao.org/

Agronomy No fes Pagl

Understanding Pesticide Label First Aid Statements and

Handling an Emergency

Consider the following scenario: A co-worker has accidentally ingested a
i small amount of concentrated pesticide from a splash that occurred while pouring
the concentrate into the sprayer's tank. What are do you do?
O Give the person water to drink?
O Help your co-worker induce vomiting?
0 Other
Properly treating a victim who has been orally exposed to a pesticide is a
serious situation. Check the Pesticide Label for first aid statements.

The pesticide label's first aid statements contain valuable information regarding treatment of victims
subjected to pesticide exposure from all major routes of entry into the body, including ocular, oral,
dermal, and inhalation.

A first aid statement is required when any acute toxicity study result is classified as Category I, II, or
III. Although not required, it is acceptable for a pesticide manufacturer to include first aid statements
on product labels for which studies have shown to be classified as Category IV. The statements will
appear under one of the following headings: "First Aid" or "Statements of Practical Treatment." If
the product is classified as toxicity Category I, the statement must appear on the label's front panel.
Products classified as toxicity Categories II and III may have their first aid statements on any panel of
the product's label. However, if they don't appear on the front panel, a referral statement such as "see
side/back panel for first aid" should appear on the front panel in close proximity to the signal word.
First aid statements are organized so that the most severe routes of exposure, as shown with the
toxicity classification, are listed first.

Table 1. Acute toxicity measures and warnings.
Category Signal word Oral LD50 mg/ Dermal LD50 Inhalation Oral lethal dose*
kg mg/kg LC50 mg/l
I Highly DANGER, 0 to 50 0 to 200 0 to 0.2 A few drops to
toxic POISON a teaspoon
(skull and cross-
II Moderately WARNING 50 to 500 200 to 2,000 0.2 to 2.0 Over a tea-
toxic spoon to one
III Slightly CAUTION 500 to 5,000 2,000 to 2.0 to 20.0 Over one ounce
toxic 20,000 to one pint
IV Relatively CAUTION 5,000+ 20,000+ 20+ Over one pint
non-toxic (or no signal to one pound
Probable for a 150-pound person.

Understanding Pesticide Label continued on Page 6


Agronomy Notes Pa

Understanding Pesticide Label
continued from Page 5
Whenever a person has to be taken


For many years, Monsanto has been preparing to register Maverick (sulfusulfuron) for use on pastures.
There have been many roadblocks along the way, but it seems as if registration is only a few months
Maverick herbicide will likely be registered for use in both bermudagrass and bahiagrass. The key weed
for this herbicide is sedeges of all types: yellow, purple, and kyllinga. Maverick is possibly the best
herbicide currently available for control of sedges. Indications are that Maverick will be labeled for "at
establishment" in bermudagrass and after establishment in bahiagrass. Additionally, there are no injury
issues associated with Maverick applications to bermudagrass or established bahiagrass as with Plateau
or Journey.
Jason Ferrell
Extension Weed Specialist
Agronomy Not fes PaM

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to an emergency facility due to a cLo .I .. ......,e., ...I al.. 1 l..). .
Call ap0'0on rl^l Ew r1o1r v a v 'a, [leam r adl
pesticide exposure, always take n.......c, ain Bay t lin E c Respon Telpon N 1-..3347577
hav a proauc conlania or label wthnyo dwi calling a poi son control c oner or oor or going For trearent
along the product label. *.,, i.a j swd.: ar........ I a.ia Ti|,al Ira .i.i. ,
Found on the label, the note to physicians provides detailed instructions for treating an exposure victim.
It is found on labels of:
All products that are classified as toxicity Category I.
S Products which are corrosive or classified as toxicity Category I for eye or skin. These
products will contain the following note to physician: "Probable mucosal damage may
contraindicate the use of gastric lavage."
Products which contain at least 10% petroleum distillate will have a note to physician
such as: "Contains petroleum distillate. Vomiting may cause aspiration pneumonia."
Products which produce physiological effects requiring specific antidotal or medical
treatment such as: cholinesterase inhibitors, metabolic stimulants, and anticoagulants.
The note to the physician is located in close proximity to the first aid statements; but, it is clearly
distinguished from it. It is not placed within the first aid statements, but appears below the first aid
The chances are slim that you or one of your co-workers will ever be a victim of pesticide exposure. But,
that doesn't mean you shouldn't know what to do in such an event. You'll never learn all of the first aid
instructions and signal words found on all product labels. The important message is to befamiliar i/ i/h
those products that you use and to keep those labels nearby in case of such an emergency.
Dr. Fred Fishel, Pesticide Information Officer