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 Table of Contents
 Cotton nitrogen needs
 July and August are bloom time...
 Asian soybean rust research
 How herbicides work - BASAGRAN
 Time to start thinking about smutgrass...
 Weed fact sheets in EDIS
 Energy impacts on row crop...
 Summer poses storage limitations...


FLAG IFAS PALMM UF



Agronomy notes
ALL VOLUMES CITATION SEARCH THUMBNAILS PAGE IMAGE ZOOMABLE
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Permanent Link: http://ufdc.ufl.edu/UF00066352/00070
 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 2006
 Subjects
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 )
 Notes
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.
Funding: Florida Historical Agriculture and Rural Life
 Record Information
Source Institution: Marston Science Library, George A. Smathers Libraries, University of Florida
Holding Location: Florida Agricultural Experiment Station, Florida Cooperative Extension Service, Florida Department of Agriculture and Consumer Services, and the Engineering and Industrial Experiment Station; Institute for Food and Agricultural Services (IFAS), University of Florida
Rights Management: All rights reserved, Board of Trustees of the University of Florida
Resource Identifier: aleph - 000956365
notis - AER9014
System ID: UF00066352:00070

Table of Contents
    Table of Contents
        Page 1
    Cotton nitrogen needs
        Page 2
    July and August are bloom time for cotton
        Page 2
    Asian soybean rust research
        Page 2
    How herbicides work - BASAGRAN
        Page 3
        Page 4
    Time to start thinking about smutgrass control
        Page 5
    Weed fact sheets in EDIS
        Page 5
    Energy impacts on row crop farmers
        Page 6 (MULTIPLE)
    Summer poses storage limitations to pesticides
        Page 6 (MULTIPLE)
        Page 7
Full Text







AGRONOMY


UNIVERSITY OF
FLORIDA
IFAS EXTENSION


NOTES


IN THIS ISSUE

COTTON

C otton N nitrogen N eeds ................................................ ................................ 2
July and August are Bloom Tim e for Cotton.................................. .....................2
WEED CONTROL

A sian Soybean R ust R research ...................................................... .....................2
How Herbicides Work BASAGRAN ....................................... ............... 3
Time to Start Thinking About Smutgrass Control................................................5
W eed F actsheets in E D IS............................................................................. 5

MISCELLANEOUS
Energy Impacts on Row Crop Farmers......................................... ............... 6
Summer Poses Storage Limitations to Pesticides.............................................6


Vol. 30:7


July 2006


DATES TO REMEMBER

August 3: Extension Row Crops Field Day, Jay, Florida.


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, Interim
Dean.










Cotton Nitrogen Needs

Late June or early July is normally the time
to sidedress N on cotton. Cotton does not
require as much N as many crops and the
need is not as critical until the squaring to
early bloom stage. Normally 50-60 lbs/A
are required to produce a bale of cotton.
However, depending on the soil and
cropping conditions, there may be 20-50
lbs/A of nitrate N available in the soil and
applications of 60-90 lbs/A of N may be
adequate for 2-3 bale yields.

Sandy soils do require more N than heavier
soils and it should be applied no later than
the 3rd week of bloom. Sulfur is especially
important on sandy soils and several
hundred pounds per acre of cotton can be
added with 30 lbs/A of S. Late foliar
applications of N are not recommended
unless boll set is poor and enough growing
season remains to set a crop. Typically, late
N applications only stimulate vegetative
growth and prolongs blooming with little
yield increase, if a good boll set occurred
early.

David Wright

July and August are Bloom Time for
Cotton

Much of the cotton that was planted in late
April and early May should be blooming by
early July and will continue to bloom
through August. The early squares should
be protected from insects and the crop
should be irrigated to keep minimize water
stress and square shed. Early boll set is very
desirable since it helps slow vegetative
growth and cuts the amount of growth
regulators needed to control plant height.
Plant bugs and stinkbugs need to be
controlled in the July-August period since
they may be coming out of small grains or


corn that was cut for grain or silage and they
are looking for succulent plants to feed on.
Our research in the past has shown that
fungicides applied during bloom period can
result in yield increases, if flowers are still
pollinating during high temperature and
humidity periods. These fungicides may be
applied with the insecticide applications for
stinkbug control. Topsin M is the only
fungicide labeled for this use at the current
time. Bt cotton often protects the plants
from feeding larvae, but does not provide
effective protection from stinkbugs.
Stinkbugs may need to be sprayed in early
July followed by another one to three
applications every two weeks as determined
by scouting. Recent research in Georgia
showed from 50-500 lb/A increase in yield
by controlling stinkbugs in Bt cotton in July
and August.

David Wright

Asian Soybean Rust Research

Florida has become a leader in research on
Asian Soybean Rust (ASR) and there is a
web site devoted to the disease and its
spread (http://www.sbrusa.net/). The
disease has not spread as rapidly as
predicted from early models and the kudzu
sites that were found to contain ASR have
not had a high incidence due to the hot, dry
weather this year. It is still early in the
season, but if ASR spreads and the disease
incidence is severe, fungicides will be
recommended for control. Sentinel soybean
plots have been planted in each of the
soybean producing states and as of late June,
only plots in Martin County Florida have
tested positive for ASR. Counties will be
notified as the disease appears and
information will be passed on to county
agents and growers as the disease gets close.
If fungicide applications are required, these
are not normally needed until bloom period










Cotton Nitrogen Needs

Late June or early July is normally the time
to sidedress N on cotton. Cotton does not
require as much N as many crops and the
need is not as critical until the squaring to
early bloom stage. Normally 50-60 lbs/A
are required to produce a bale of cotton.
However, depending on the soil and
cropping conditions, there may be 20-50
lbs/A of nitrate N available in the soil and
applications of 60-90 lbs/A of N may be
adequate for 2-3 bale yields.

Sandy soils do require more N than heavier
soils and it should be applied no later than
the 3rd week of bloom. Sulfur is especially
important on sandy soils and several
hundred pounds per acre of cotton can be
added with 30 lbs/A of S. Late foliar
applications of N are not recommended
unless boll set is poor and enough growing
season remains to set a crop. Typically, late
N applications only stimulate vegetative
growth and prolongs blooming with little
yield increase, if a good boll set occurred
early.

David Wright

July and August are Bloom Time for
Cotton

Much of the cotton that was planted in late
April and early May should be blooming by
early July and will continue to bloom
through August. The early squares should
be protected from insects and the crop
should be irrigated to keep minimize water
stress and square shed. Early boll set is very
desirable since it helps slow vegetative
growth and cuts the amount of growth
regulators needed to control plant height.
Plant bugs and stinkbugs need to be
controlled in the July-August period since
they may be coming out of small grains or


corn that was cut for grain or silage and they
are looking for succulent plants to feed on.
Our research in the past has shown that
fungicides applied during bloom period can
result in yield increases, if flowers are still
pollinating during high temperature and
humidity periods. These fungicides may be
applied with the insecticide applications for
stinkbug control. Topsin M is the only
fungicide labeled for this use at the current
time. Bt cotton often protects the plants
from feeding larvae, but does not provide
effective protection from stinkbugs.
Stinkbugs may need to be sprayed in early
July followed by another one to three
applications every two weeks as determined
by scouting. Recent research in Georgia
showed from 50-500 lb/A increase in yield
by controlling stinkbugs in Bt cotton in July
and August.

David Wright

Asian Soybean Rust Research

Florida has become a leader in research on
Asian Soybean Rust (ASR) and there is a
web site devoted to the disease and its
spread (http://www.sbrusa.net/). The
disease has not spread as rapidly as
predicted from early models and the kudzu
sites that were found to contain ASR have
not had a high incidence due to the hot, dry
weather this year. It is still early in the
season, but if ASR spreads and the disease
incidence is severe, fungicides will be
recommended for control. Sentinel soybean
plots have been planted in each of the
soybean producing states and as of late June,
only plots in Martin County Florida have
tested positive for ASR. Counties will be
notified as the disease appears and
information will be passed on to county
agents and growers as the disease gets close.
If fungicide applications are required, these
are not normally needed until bloom period










Cotton Nitrogen Needs

Late June or early July is normally the time
to sidedress N on cotton. Cotton does not
require as much N as many crops and the
need is not as critical until the squaring to
early bloom stage. Normally 50-60 lbs/A
are required to produce a bale of cotton.
However, depending on the soil and
cropping conditions, there may be 20-50
lbs/A of nitrate N available in the soil and
applications of 60-90 lbs/A of N may be
adequate for 2-3 bale yields.

Sandy soils do require more N than heavier
soils and it should be applied no later than
the 3rd week of bloom. Sulfur is especially
important on sandy soils and several
hundred pounds per acre of cotton can be
added with 30 lbs/A of S. Late foliar
applications of N are not recommended
unless boll set is poor and enough growing
season remains to set a crop. Typically, late
N applications only stimulate vegetative
growth and prolongs blooming with little
yield increase, if a good boll set occurred
early.

David Wright

July and August are Bloom Time for
Cotton

Much of the cotton that was planted in late
April and early May should be blooming by
early July and will continue to bloom
through August. The early squares should
be protected from insects and the crop
should be irrigated to keep minimize water
stress and square shed. Early boll set is very
desirable since it helps slow vegetative
growth and cuts the amount of growth
regulators needed to control plant height.
Plant bugs and stinkbugs need to be
controlled in the July-August period since
they may be coming out of small grains or


corn that was cut for grain or silage and they
are looking for succulent plants to feed on.
Our research in the past has shown that
fungicides applied during bloom period can
result in yield increases, if flowers are still
pollinating during high temperature and
humidity periods. These fungicides may be
applied with the insecticide applications for
stinkbug control. Topsin M is the only
fungicide labeled for this use at the current
time. Bt cotton often protects the plants
from feeding larvae, but does not provide
effective protection from stinkbugs.
Stinkbugs may need to be sprayed in early
July followed by another one to three
applications every two weeks as determined
by scouting. Recent research in Georgia
showed from 50-500 lb/A increase in yield
by controlling stinkbugs in Bt cotton in July
and August.

David Wright

Asian Soybean Rust Research

Florida has become a leader in research on
Asian Soybean Rust (ASR) and there is a
web site devoted to the disease and its
spread (http://www.sbrusa.net/). The
disease has not spread as rapidly as
predicted from early models and the kudzu
sites that were found to contain ASR have
not had a high incidence due to the hot, dry
weather this year. It is still early in the
season, but if ASR spreads and the disease
incidence is severe, fungicides will be
recommended for control. Sentinel soybean
plots have been planted in each of the
soybean producing states and as of late June,
only plots in Martin County Florida have
tested positive for ASR. Counties will be
notified as the disease appears and
information will be passed on to county
agents and growers as the disease gets close.
If fungicide applications are required, these
are not normally needed until bloom period










which would be in July and August
depending on planting date and maturity
group.

David Wright and James Marois

How Herbicides Work BASAGRAN

This is a monthly addition to Agronomy
Notes that will cover the mode of action of
various herbicides. Each month a different
herbicide, or group of similar acting
herbicides, will be covered. Currently, there
are over 150 individual molecules that
comprise several thousand herbicides.
Simply stated, this will go on for a while. I
will use the most popular trade name for
reader familiarity in the title, but will refer
to the actual compound name (or common
name) in the text. I will use no particular
order month by month, but will try to choose
an herbicide that might be extensively used
during that time of year.

Basagran, common name bentazon, is an
herbicide that has been in use for over 30
years. It was first registered for use in
soybeans and rice but has subsequently been
expanded to cover a wide range of crops,
including corn, dry beans, mint, peanuts,
sorghum, potatoes, sugarcane, alfalfa and
several types ofturfgrass. This compound is
unique because it is one of the few
photosynthetic-inhibiting herbicides that
have activity on nutsedges. It also controls
several types of broadleaf weeds.

Bentazon is classified as a photosynthesis
inhibitor. This herbicide is applied
postemergence, over the top of both weeds
and crops. It is absorbed by the leaves and
diffuses into cells and then into the
chloroplasts of cells. Chloroplasts are those
green dots within the leaf cells as shown in


figure 1. Basically, bentazon follows the
same path as the arrow for sunlight.


PHOTOSYTHENSIS


RTER UI IT CIEMIPCL ENEURY.


I iMo'oplPtI.I U~i -II


LOlN Gnur*


:.--o
. --1 -m.Uai

SICH, i~l. IW~+ 4 CW M U
04EMKAL ENERGY+ CARBON VIOXVE -SUGAR~


Figure 1 Adapted from:
www. caribbeanedu.com

Once inside the chloroplast, bentazon moves
to the thylakoids, which are membranes
within the chloroplast (Figure 2).


CHLOROPLAST
DOUBLE MEMBtRANE ENVELOPE \ T-5
OUTER EMBRANE---
INNER MEMBRANE-.


RAINS
TIC MATERIAL


RI305VCEf


-...- C pLONa CDM
'~'5 TROMA LAMELLAE
Figure 2 Adapted from:
www.ftexploring.com


;i









Thylakoid membranes contain a series of
complex proteins with figure 3 showing a
cross-section of a thylakoid membrane.
These proteins are embedded within the
thylakoid membrane and function to capture
light energy. This energy is captured in the
form of electrons (e- in the figure below)
and are passed through the proteins to form
intermediates used for carbon fixation.
Bentazon binds to a protein in photosystem
II, thereby blocking the flow of electrons.


destruct, oxygen radicals are formed. Then
the chloroplast membranes and eventually
outer cell membranes become ruptured.
This leads to necrotic tissue, taking on the
appearance of a brown paper bag.


photosystem II
electron
transport
system
photosystem I
electron
transport
system


Figure 4 Image from:
www.ridgetownc.on ca/services/


Figure 3 Adapted from:
www.icb.ufmg.br

When this electron flow is blocked,
intermediates are not formed and the plant
cannot fix carbon. Without carbon, the plant
cannot continue to grow and perform normal
functions. In addition to blocking electron
flow, another important problem arises
within the chloroplast. Sunlight continues to
shine and the chlorophyll molecules
continue to absorb light energy. There are
approximately 300 chlorophyll molecules
feeding energy into each complex shown
above in figure 3. With electron flow
blocked by bentazon, the chlorophyll
molecules cannot dissipate the energy
absorbed from sunlight. Unable to dissipate
energy, they self-destruct.

This cascade of events helps to explain the
symptoms observed after applying bentazon.
First, the plant begins to show yellowing of
the leaves as the chlorophyll molecules
disintegrate. Once the chlorophyll begins


Figure 5 Image from:
www.omafragov.on.ca


Notice that the injury is local and does not
appear on the new growth. Bentazon
behaves as a contact herbicide and does not
move up or down within the plant.
Therefore coverage is essential for good
control. In addition, an adjuvant is needed
to aid in bentazon penetrating the cuticle on
the lead surface. The images above are
injury to soybean, and bentazon is labeled









for use in soybean. Conditions such as high
humidity, especially when using crop oil,
may sometimes cause injury. Crops tolerate
bentazon by breaking down metabolizingg)
the herbicide into non-toxic by-products.
Bentazon has limited soil persistence and
possesses very little to no soil activity.

Greg MacDonald

Time to Start Thinking About Smutgrass
Control

It's that time of year again. The rainy
season is just beginning, and most
everything is turning from brown to green,
including our most troublesome grass weed
- smutgrass. We get many questions each
year concerning different cultural practices
for smutgrass control. Should we mow, or
burn, or anything?

We know that we can control smutgrass
with Velpar. Currently, we recommend 3
pt/acre (0.75 lb ai/acre) for small smutgrass,
and 4 pt/acre (1.0 lb ai/acre) for giant
smutgrass. Why start thinking about
smutgrass control now? Velpar works
primarily through root uptake, meaning
rainfall is needed to move Velpar into the
soil solution so it is available for root
uptake.

What about mowing and/or burning
smutgrass before Velpar application?
Simply speaking, there is no advantage or
disadvantage to using these cultural
practices before applying Velpar.
Furthermore, mowing has been suggested to
increase seed spread, and burning has been
said to increase smutgrass seed germination.
However, these practices will encourage
grazing of these plants for 1 to 3 weeks and
research has shown that smutgrass has
similar forage quality to that of bahiagrass.


When is the best time to apply Velpar? The
best time appears to be any time during the
rainy season from July through September.
Dr. Mislevy's work with small smutgrass
showed similar control when Velpar was
applied in late July compared to late
September. Remember that rainfall is the
key to smutgrass control with Velpar.

Do I need to apply an adjuvant with Velpar?
This is a good question that we continue to
evaluate. Most of the activity from Velpar
comes from root uptake, however, there is
some foliar activity. The addition of an
adjuvant may aid in control if rain does not
occur within a week after Velpar
application. However, our data from 2005
indicates that the addition of an adjuvant did
not increase smutgrass control compared to
Velpar alone.

Smutgrass continues to be our most
problematic grass weed species in pastures.
Applying Velpar will control existing
smutgrass plants for at least a year.
Management of the pasture after Velpar
application may be the key to long-term
management of smutgrass. We are currently
investigating best management practices for
smutgrass control.

Brent A. Sellers

Weed Factsheets in EDIS

As we all know, EDIS is a great place to
store useful extension information, but this
information can be difficult to find.
Additionally, it can be hard to keep track of
newly written EDIS publications.

Below is a list of EDIS factsheets that have
recently been written or updated for pasture
weeds.









for use in soybean. Conditions such as high
humidity, especially when using crop oil,
may sometimes cause injury. Crops tolerate
bentazon by breaking down metabolizingg)
the herbicide into non-toxic by-products.
Bentazon has limited soil persistence and
possesses very little to no soil activity.

Greg MacDonald

Time to Start Thinking About Smutgrass
Control

It's that time of year again. The rainy
season is just beginning, and most
everything is turning from brown to green,
including our most troublesome grass weed
- smutgrass. We get many questions each
year concerning different cultural practices
for smutgrass control. Should we mow, or
burn, or anything?

We know that we can control smutgrass
with Velpar. Currently, we recommend 3
pt/acre (0.75 lb ai/acre) for small smutgrass,
and 4 pt/acre (1.0 lb ai/acre) for giant
smutgrass. Why start thinking about
smutgrass control now? Velpar works
primarily through root uptake, meaning
rainfall is needed to move Velpar into the
soil solution so it is available for root
uptake.

What about mowing and/or burning
smutgrass before Velpar application?
Simply speaking, there is no advantage or
disadvantage to using these cultural
practices before applying Velpar.
Furthermore, mowing has been suggested to
increase seed spread, and burning has been
said to increase smutgrass seed germination.
However, these practices will encourage
grazing of these plants for 1 to 3 weeks and
research has shown that smutgrass has
similar forage quality to that of bahiagrass.


When is the best time to apply Velpar? The
best time appears to be any time during the
rainy season from July through September.
Dr. Mislevy's work with small smutgrass
showed similar control when Velpar was
applied in late July compared to late
September. Remember that rainfall is the
key to smutgrass control with Velpar.

Do I need to apply an adjuvant with Velpar?
This is a good question that we continue to
evaluate. Most of the activity from Velpar
comes from root uptake, however, there is
some foliar activity. The addition of an
adjuvant may aid in control if rain does not
occur within a week after Velpar
application. However, our data from 2005
indicates that the addition of an adjuvant did
not increase smutgrass control compared to
Velpar alone.

Smutgrass continues to be our most
problematic grass weed species in pastures.
Applying Velpar will control existing
smutgrass plants for at least a year.
Management of the pasture after Velpar
application may be the key to long-term
management of smutgrass. We are currently
investigating best management practices for
smutgrass control.

Brent A. Sellers

Weed Factsheets in EDIS

As we all know, EDIS is a great place to
store useful extension information, but this
information can be difficult to find.
Additionally, it can be hard to keep track of
newly written EDIS publications.

Below is a list of EDIS factsheets that have
recently been written or updated for pasture
weeds.









* Blackberry and Dewberry: Biology and
Control
* Common Pokeweed
* Dogfennel (Eupatorium capillifolium):
Biology and Control
* Fireweed (Heartleaf nettle) Control in
Pastures
* Herbicide Application Techniques for
Woody Plant Control
* Managing Bahiagrass in Hybrid
Bermudagrass Pastures
* Thistle Control in Pastures
* Tropical Soda Apple (Solanum viarum
Dunal) in Florida
* Wild Radish: Biology and Control

All of these publications are currently
located in one convenient location:
www.uflweed.com. By simply clicking on
the "factsheets" tab and select "weeds", you
will be directed to all these factsheets.

Jason Ferrell

Energy Impacts on Row Crop Farmers

Modern farming practices are impacted to a
high degree from price of energy since
almost every phase of farming depends on
crude oil. Fertilizers and farm chemicals are
manufactured through use of petroleum
products. Tractors, trucks and harvest
equipment all run on fossil fuels. Grain is
dried and transported through use of these
fuels. Drastic changes need to be made for
farming to become less dependent on oil for
growing crops. Using crops to produce oil
may help growers meet energy demands.
Some of the crops with high oil content that
can be grown in the SE are soybeans (about
18% oil), peanut (about 48-50% oil), castor
bean (about 50% oil), canola (about 35-40%
oil). These crops and others may eventually
make an impact on oil use in the U.S.
However, the infrastructure is just being put
in place for use of crops for oil and ethanol
production. The longer prices for petroleum


stays high, the more energy independent the
U.S. will become through development of
alternate energy sources.

David Wright

Summer Poses Storage Limitations to
Pesticides

With the onset of summer, most think of
hurricane season bearing down upon
Florida. While hurricanes may wreak havoc
on certain areas, soaring temperatures are
experienced by the entire state. Extremely
hot temperatures can adversely affect the
storage life of pesticides particularly those
not stored in a temperature-controlled
environment. Most labels of liquid
pesticides that contain specific information
on adequate storage temperatures for their
products will generally state a temperature
in the 40 to 1000 F range.

What does heat do to liquid pesticides? Heat
can cause some pesticides to volatilize and
drift from their containers, especially if
containers are not adequately sealed.
Flammability is a problem with some
products in the presence of heat and/or open
flame. It is discussed in more detail in
UF/IFAS EDIS Extension Document PI-97,
"Pesticide Labeling: Physical or Chemical
Hazards" http://edis.ifas.ufl.edu/PI134. High
temperatures can also adversely affect
containers, causing melting of plastic
containers and glass to explode. The liquid
pesticide contents in metal drums can cause
expansion and eventual rupturing.

What does heat do to dry pesticides?
Generally, dry pesticide formulations are not
adversely affected by high temperature
extremes. Their effectiveness is most often
reduced by the presence of moisture in
storage. These products have a high affinity
for water and once absorbed, may solidify
into hard masses (tombstone formation). The









* Blackberry and Dewberry: Biology and
Control
* Common Pokeweed
* Dogfennel (Eupatorium capillifolium):
Biology and Control
* Fireweed (Heartleaf nettle) Control in
Pastures
* Herbicide Application Techniques for
Woody Plant Control
* Managing Bahiagrass in Hybrid
Bermudagrass Pastures
* Thistle Control in Pastures
* Tropical Soda Apple (Solanum viarum
Dunal) in Florida
* Wild Radish: Biology and Control

All of these publications are currently
located in one convenient location:
www.uflweed.com. By simply clicking on
the "factsheets" tab and select "weeds", you
will be directed to all these factsheets.

Jason Ferrell

Energy Impacts on Row Crop Farmers

Modern farming practices are impacted to a
high degree from price of energy since
almost every phase of farming depends on
crude oil. Fertilizers and farm chemicals are
manufactured through use of petroleum
products. Tractors, trucks and harvest
equipment all run on fossil fuels. Grain is
dried and transported through use of these
fuels. Drastic changes need to be made for
farming to become less dependent on oil for
growing crops. Using crops to produce oil
may help growers meet energy demands.
Some of the crops with high oil content that
can be grown in the SE are soybeans (about
18% oil), peanut (about 48-50% oil), castor
bean (about 50% oil), canola (about 35-40%
oil). These crops and others may eventually
make an impact on oil use in the U.S.
However, the infrastructure is just being put
in place for use of crops for oil and ethanol
production. The longer prices for petroleum


stays high, the more energy independent the
U.S. will become through development of
alternate energy sources.

David Wright

Summer Poses Storage Limitations to
Pesticides

With the onset of summer, most think of
hurricane season bearing down upon
Florida. While hurricanes may wreak havoc
on certain areas, soaring temperatures are
experienced by the entire state. Extremely
hot temperatures can adversely affect the
storage life of pesticides particularly those
not stored in a temperature-controlled
environment. Most labels of liquid
pesticides that contain specific information
on adequate storage temperatures for their
products will generally state a temperature
in the 40 to 1000 F range.

What does heat do to liquid pesticides? Heat
can cause some pesticides to volatilize and
drift from their containers, especially if
containers are not adequately sealed.
Flammability is a problem with some
products in the presence of heat and/or open
flame. It is discussed in more detail in
UF/IFAS EDIS Extension Document PI-97,
"Pesticide Labeling: Physical or Chemical
Hazards" http://edis.ifas.ufl.edu/PI134. High
temperatures can also adversely affect
containers, causing melting of plastic
containers and glass to explode. The liquid
pesticide contents in metal drums can cause
expansion and eventual rupturing.

What does heat do to dry pesticides?
Generally, dry pesticide formulations are not
adversely affected by high temperature
extremes. Their effectiveness is most often
reduced by the presence of moisture in
storage. These products have a high affinity
for water and once absorbed, may solidify
into hard masses (tombstone formation). The










packaging that surrounds dry products
formulated as water-soluble packets can
become brittle after taking on moisture.

To learn of storage temperature limitations
for individual products, consult the "Storage
and Disposal" section of the pesticide's
label; some will have no limitations. Many
products will have specific temperature
limitations mentioned in this section; others
may be more general. The UF/IFAS
Pesticide Information Office recently
published two guides that specifically
address product storage limitations. Many
fungicide products registered for use in
Florida may be referenced by accessing


"Storage Limitation Statements:
Temperature Fungicides" at
http://edis.ifas.ufl.edu/PI159. Many
herbicide products registered for use in
Florida may be referenced by accessing
"Storage Limitation Statements:
Temperature Herbicides" at
http://edis.ifas.ufl.edu/PI 160. Each
publication contains tables with specific
temperature and other storage statements
taken from products' labels. If you have
questions regarding these limitations,
consult the product's manufacturer.

Fred Fishel


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.
Preparedby: J.M. Bennett, Chairman; M.B. Adjei, Forage Agronomist ii. ..ii, ;,i ,,li .1.i, J.A. Ferrell, Extension Agronomist
I I,. II, 1i 1.iil F.M Fishel, Pesticide C(..1 .1 ii-. .I.I.i .1 ,il .1.i,, C.R. Rainbolt, Extension Agronomist
,..11..1 h.,.1 ,i .1., .I B.A. Sellers, Extension Agronomist II,. 1.. .1i .l .i 11 D.L. Wright, Extension Agronomist (dlw@ifas.ufl.edu).