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 Table of Contents
 Hay feeding losses
 Judging hay quality
 Frosted pastures may bring...
 Coffee weed
 Frosted sorghums
 Castor bean
 Grass tetany in cattle
 Tobacco varieties for 2004
 Tobacco quota for 2004
 Checking tobacco barns
 Bahiagrass rotation
 Deep tillage in continuous row...
 November crop report
 New publications


FLAG IFAS PALMM UF



Agronomy notes
ALL VOLUMES CITATION SEARCH THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00066352/00041
 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: December 2003
 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: UF00066352:00041

Table of Contents
    Table of Contents
        Page 1
    Hay feeding losses
        Page 2
    Judging hay quality
        Page 2
    Frosted pastures may bring problems
        Page 3
    Coffee weed
        Page 3
    Frosted sorghums
        Page 4
    Castor bean
        Page 4
    Grass tetany in cattle
        Page 5
    Tobacco varieties for 2004
        Page 5
    Tobacco quota for 2004
        Page 6
    Checking tobacco barns
        Page 6
    Bahiagrass rotation
        Page 6
    Deep tillage in continuous row crops
        Page 6
    November crop report
        Page 7
    New publications
        Page 7
Full Text






AGRONOMY
UNIVERSITY OF
FLORIDA NOTES
IFAS EXTENSION
December, 2003

DATES TO REMEMBER

Feb. 24-25, 2004 FL Weed Science Society Annual Meeting, Ft. Pierce
May 22, 2004 4th Annual Perennial Peanut Field Day, Moultrie, GA
May 27, 2004 Corn Silage Field Day, Citra



IN THIS ISSUE

FORAGE
Hay Feeding Losses ................................................ 2
Judging H ay Q quality ...................................... ......... 2
Frosted Pastures M ay Bring Problems ............... ............... 3
Coffee W eed .......................................... 3
Frosted Sorghums ................................................. 4
C astor B ean ............... ................. ........ ......... 4
G rass Tetany in C attle ............... .................. ....... 5

TOBACCO
Tobacco Varieties for 2004 ............... ................. ...... 5
Tobacco Quota for 2004 ................................ ........ 6
Checking Tobacco Barns ................................ ....... 6

MISCELLANEOUS
Bahiagrass Rotation ........................................... 6
Deep Tillage in Continuous Row Crops ................................ 6
November Crop Report ............................................. 7
New Publications ................ ............................ 7





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 / Christine Taylor
Waddill, Director.










Hay Feeding Losses

This is the time of year when we need to be
concerned about hay feeding losses. This is
especially true when feeding large round bales
that have not only been stored outside (where
considerable weathering loss has occurred), but
will also be fed outside on the ground. Feeding
losses can occur with any feeding system; the
objective should be to minimize the loss so that
animals can consume most of the hay given to
them.

Most large hay packages are fed on sod and
offers the advantage of distributing hay on
pasture land rather than concentrating it along a
feed bunk or in a barn. When hay is fed on sod,
livestock usually waste and refuse less hay in
situations in which they have a solid footing.
Dry, well-drained, sites should therefore be
chosen for feeding hay outside.

Feeding in only one area permits selection of a
convenient feeding location which is easily
accessible and which minimizes the size of the
area in which sod is killed. However, it causes
excessive sod destruction, may create muddy
conditions, often results in heavy spring weed
pressure, and can result in soil compaction
and/or ruts in the pasture.

Some livestock producers who feed in only one
area prefer to feed on concrete or to haul in large
gravel so the hay can be placed on a solid
foundation. Also, some producers feed the
lowest quality hay first, thus initially causing
excessive hay wastage but providing a
foundation for further feeding.

Frequently moving the feeding area allows
manure to be spread more uniformly over the
pasture(s) and therefore improves the soil
fertility in bare or thin spots, while reducing the
severity (though not necessarily the total area) of
sod damage.

When hay is fed on sod, the amount of hay
wasted will be much less when only a one-day
hay supply is given, and when hay is fed in such
a manner that all animals have access. However,
unrestricted animal access to large round bales


or stacks will result in grossly excessive feeding
waste.

If substantial quantities of hay must be put out at
one time, erecting a barrier between the hay and
the feeding animals will reduce waste. The
barrier can be an electric wire, feeding racks or
rings, panels, wagons or gates. Feeding racks
and rings are available in a variety of shapes and
sizes. Racks which prevent hay from contacting
the ground are particularly effective.

When racks or panels are not used, enough
animals are needed to eat the amount of hay
offered in a relatively short period of time.
Waste can be reduced by having at least one cow
for each foot of outside dimension
(circumference) of the hay package. (Source:
Don Ball et.al. in Minimizing Losses in Hay
Storage and Feeding).

CGC

Judging Hay Quality

Most of the hay fed to beef cattle in Florida is
bermudagrass, bahia, or some other warm season
perennial grass. Alfalfa and other temperate
forages are often purchased and fed to horses. If
a laboratory test is not available that gives
protein and digestibility values, one can get
some idea of the feeding value by "sensory"
examination of the hay.

First determining the plant species in the hay can
be helpful. Does one species tend to be higher
in quality than the other. If the hay is pure
perennial peanut, it is likely to be more
digestible, more palatable, and have a higher
protein content than a hay that is 50% peanut
and 50% common bermudagrass. Mixed
bermudagrass and bahia may have a nutritional
value equal to a pure bermudagrass hay, but may
be discounted by the buyer because of the
difference in color of the two grasses in the hay.

Maturity of the plants at the time they are cut to
make hay is the most important factor in
determining hay quality. If you know when the
previous cutting was made then you can
determine the age of the hay crop. This can be










Hay Feeding Losses

This is the time of year when we need to be
concerned about hay feeding losses. This is
especially true when feeding large round bales
that have not only been stored outside (where
considerable weathering loss has occurred), but
will also be fed outside on the ground. Feeding
losses can occur with any feeding system; the
objective should be to minimize the loss so that
animals can consume most of the hay given to
them.

Most large hay packages are fed on sod and
offers the advantage of distributing hay on
pasture land rather than concentrating it along a
feed bunk or in a barn. When hay is fed on sod,
livestock usually waste and refuse less hay in
situations in which they have a solid footing.
Dry, well-drained, sites should therefore be
chosen for feeding hay outside.

Feeding in only one area permits selection of a
convenient feeding location which is easily
accessible and which minimizes the size of the
area in which sod is killed. However, it causes
excessive sod destruction, may create muddy
conditions, often results in heavy spring weed
pressure, and can result in soil compaction
and/or ruts in the pasture.

Some livestock producers who feed in only one
area prefer to feed on concrete or to haul in large
gravel so the hay can be placed on a solid
foundation. Also, some producers feed the
lowest quality hay first, thus initially causing
excessive hay wastage but providing a
foundation for further feeding.

Frequently moving the feeding area allows
manure to be spread more uniformly over the
pasture(s) and therefore improves the soil
fertility in bare or thin spots, while reducing the
severity (though not necessarily the total area) of
sod damage.

When hay is fed on sod, the amount of hay
wasted will be much less when only a one-day
hay supply is given, and when hay is fed in such
a manner that all animals have access. However,
unrestricted animal access to large round bales


or stacks will result in grossly excessive feeding
waste.

If substantial quantities of hay must be put out at
one time, erecting a barrier between the hay and
the feeding animals will reduce waste. The
barrier can be an electric wire, feeding racks or
rings, panels, wagons or gates. Feeding racks
and rings are available in a variety of shapes and
sizes. Racks which prevent hay from contacting
the ground are particularly effective.

When racks or panels are not used, enough
animals are needed to eat the amount of hay
offered in a relatively short period of time.
Waste can be reduced by having at least one cow
for each foot of outside dimension
(circumference) of the hay package. (Source:
Don Ball et.al. in Minimizing Losses in Hay
Storage and Feeding).

CGC

Judging Hay Quality

Most of the hay fed to beef cattle in Florida is
bermudagrass, bahia, or some other warm season
perennial grass. Alfalfa and other temperate
forages are often purchased and fed to horses. If
a laboratory test is not available that gives
protein and digestibility values, one can get
some idea of the feeding value by "sensory"
examination of the hay.

First determining the plant species in the hay can
be helpful. Does one species tend to be higher
in quality than the other. If the hay is pure
perennial peanut, it is likely to be more
digestible, more palatable, and have a higher
protein content than a hay that is 50% peanut
and 50% common bermudagrass. Mixed
bermudagrass and bahia may have a nutritional
value equal to a pure bermudagrass hay, but may
be discounted by the buyer because of the
difference in color of the two grasses in the hay.

Maturity of the plants at the time they are cut to
make hay is the most important factor in
determining hay quality. If you know when the
previous cutting was made then you can
determine the age of the hay crop. This can be










very helpful with bermudagrass or bahiagrass
hay. Temperate grasses (timothy and others)
produce seed heads as they mature and therefore
the presence of seed heads in the hay is an
indication of advanced maturity and perhaps
lower quality, but the warm season grasses do
not always produce seed heads before they are
overly mature.
Examining the texture of the hay can be useful
in determining maturity. Plant stems that are
soft and pliable indicates young immature
plants. As the plant matures the stems become
more lignified and therefore stiffness of the stem
increases. Are the stems stiff or even brittle?

Texture of the hay can be an important clue to
maturity and forage quality. Very young
immature hay is soft and pliable and stems are
hardly distinguishable from leaves. Hays can
range from very soft to harsh and brittle. Leaf
content and moisture level at baling can also
affect texture.

Leaf content affects hay quality. The higher the
leaf content, the higher the forage quality. Plant
species, maturity at harvest, and handling of the
hay that results in leaf loss affect leafiness of the
hay. The producer must be especially careful
when tedding, raking and baling legumes hays in
order to avoid excessive leaf loss.

Color is the first thing many buyers consider
when purchasing hay. Color may or may not be
a good indicator of forage quality. A bright
green or light green color indicates that hay was
dried quickly and stored under a cover. A hay
crop will lose color when rained on, which may
be due to leaching and mold or fungal growth.
Prolonged exposure to sunlight will bleach hay.
Baling at a moisture content of 20% or greater
may result in heating and internal browning in
the hay bale.

Smell the hay. A pleasant odor indicates hay
was cured properly. Moldy, musty odors may
occur in hay stored at moisture contents greater
than 15%. Such odors may reduce intake by the
animal. A caramelized odor is caused by
heating to temperatures greater than 125 degrees
F. Heating occurs when hay is baled at too high
a moisture content. Is the hay dusty? Dust


usually results from soil being thrown into the
hay as it is raked. Excessive mold or mold
spores may appear as a dust when the hay bale is
fed.

Look for weeds. Often weeds do not dry
completely and may cause localized molding.
How much weed content is there in the hay?
Does the weed have any nutritional value? Is it
toxic? Coffee senna in a bale of alyceclover hay
would be a serious problem.

Look for trash. Tree leaves, cow dung, plastic,
aluminum cans, sticks and dead snakes are
undesirable.

CGC

Frosted Pastures May Bring Problems

Over the past few years I have seen or heard
reports of cattle eating coffee weed soon after a
frost. Cattle producers should be aware of this
potential problem and mow these poisonous
plants before frost occurs. Animals may not
have grazed coffee weed all year but may start
grazing them after a frost.

CGC

Coffee Weed

A publication SP 57, "Poisonous Plants of the
Southeastern United States" is available from
the University of Florida Institute of Food and
Agricultural Sciences for the cost of $4.00.

Recently, there have been reports of animal
deaths from eating coffee weed. There are two
plants commonly called coffee weed that can
cause a problem; these are sicklepod (Senna
obtusifolia) and coffee senna (Cassia
occidentalis).

The following comes from the older book
entitled "Poisonous Plants of the Southern
United States": Both plants are summer
annuals. Coffee senna is very similar to
sicklepod but has mostly 8 or more leaflets
rather than 4 to 6. The pods on coffee senna are
flattened while those of sickle pod are nearly










very helpful with bermudagrass or bahiagrass
hay. Temperate grasses (timothy and others)
produce seed heads as they mature and therefore
the presence of seed heads in the hay is an
indication of advanced maturity and perhaps
lower quality, but the warm season grasses do
not always produce seed heads before they are
overly mature.
Examining the texture of the hay can be useful
in determining maturity. Plant stems that are
soft and pliable indicates young immature
plants. As the plant matures the stems become
more lignified and therefore stiffness of the stem
increases. Are the stems stiff or even brittle?

Texture of the hay can be an important clue to
maturity and forage quality. Very young
immature hay is soft and pliable and stems are
hardly distinguishable from leaves. Hays can
range from very soft to harsh and brittle. Leaf
content and moisture level at baling can also
affect texture.

Leaf content affects hay quality. The higher the
leaf content, the higher the forage quality. Plant
species, maturity at harvest, and handling of the
hay that results in leaf loss affect leafiness of the
hay. The producer must be especially careful
when tedding, raking and baling legumes hays in
order to avoid excessive leaf loss.

Color is the first thing many buyers consider
when purchasing hay. Color may or may not be
a good indicator of forage quality. A bright
green or light green color indicates that hay was
dried quickly and stored under a cover. A hay
crop will lose color when rained on, which may
be due to leaching and mold or fungal growth.
Prolonged exposure to sunlight will bleach hay.
Baling at a moisture content of 20% or greater
may result in heating and internal browning in
the hay bale.

Smell the hay. A pleasant odor indicates hay
was cured properly. Moldy, musty odors may
occur in hay stored at moisture contents greater
than 15%. Such odors may reduce intake by the
animal. A caramelized odor is caused by
heating to temperatures greater than 125 degrees
F. Heating occurs when hay is baled at too high
a moisture content. Is the hay dusty? Dust


usually results from soil being thrown into the
hay as it is raked. Excessive mold or mold
spores may appear as a dust when the hay bale is
fed.

Look for weeds. Often weeds do not dry
completely and may cause localized molding.
How much weed content is there in the hay?
Does the weed have any nutritional value? Is it
toxic? Coffee senna in a bale of alyceclover hay
would be a serious problem.

Look for trash. Tree leaves, cow dung, plastic,
aluminum cans, sticks and dead snakes are
undesirable.

CGC

Frosted Pastures May Bring Problems

Over the past few years I have seen or heard
reports of cattle eating coffee weed soon after a
frost. Cattle producers should be aware of this
potential problem and mow these poisonous
plants before frost occurs. Animals may not
have grazed coffee weed all year but may start
grazing them after a frost.

CGC

Coffee Weed

A publication SP 57, "Poisonous Plants of the
Southeastern United States" is available from
the University of Florida Institute of Food and
Agricultural Sciences for the cost of $4.00.

Recently, there have been reports of animal
deaths from eating coffee weed. There are two
plants commonly called coffee weed that can
cause a problem; these are sicklepod (Senna
obtusifolia) and coffee senna (Cassia
occidentalis).

The following comes from the older book
entitled "Poisonous Plants of the Southern
United States": Both plants are summer
annuals. Coffee senna is very similar to
sicklepod but has mostly 8 or more leaflets
rather than 4 to 6. The pods on coffee senna are
flattened while those of sickle pod are nearly










four-sided. Also, coffee senna pods tend to be
straighter and shorter than those of sicklepod.
[The end of leaflets of coffee senna are pointed
whereas those of sicklepod tend to be rounded].
These plants are found throughout the south but
are more abundant on sandy soils of the coastal
plain, and are most abundant in cultivated fields,
roadsides, waste places and open pinelands.

Toxicity: The toxic principles have not been
clearly established. The seeds appear to exert
their toxicity upon the skeletal muscles, kidney,
and liver. The leaves and stem also contain
toxin, whether green or dry. Sicklepod is much
more prevalent but somewhat less toxic than
coffee senna. Animals can be poisoned by
consuming the plant in the field, in green chop,
in hay or if the seed is mixed in grain. Toxicity
has been observed in cattle. It should be
assumed that other animals are susceptible to the
effects of these plants.

Symptoms: Diarrhea is usually the first
symptom observed. Later, the animals go off
feed, appear lethargic, and tremors appear in the
hind legs, indicating muscle degeneration. As
the muscle degeneration progresses, the urine
becomes dark and coffee-colored and the animal
becomes recumbent and is unable to rise. Death
often occurs within 12 hours after the animal
goes down. There is no fever.

Treatment: Once animals become recumbent,
treatment is usually ineffective. Selenium and
Vitamin E injections have been used with
variable results.

CGC

Frosted Sorghums

Sorghums, sudangrass, and johnsongrass will
produce prussic acid after a frost or freeze. The
frosted forage will produce large quantities of
prussic acid when the plant cells break down in
the cow's rumen. This may cause prussic acid
(HCN) poisoning. If the forage is allowed to
dry for 3 to 6 days it should be safe to consume.
As the plants dry, the toxic compound will be
released to the atmosphere as a gas. In the fall,
remove animals from these pastures when frost


is eminent. [Pearl millet does not produce
prussic acid.]

Also do not allow animals to graze young
regrowth that may appear in south Florida after
the tops have been killed by a frost. At any time
during the growing season, always allow these
plants to reach a height of 18 to 24 inches before
grazing since the young plants have a higher
concentration of prussic acid, frost or no frost,
and can be dangerous.

Frosted sorghums can be harvested for silage.
The danger of prussic acid poisoning is
minimized since the forage is chopped coming
out of the field and then handled again when
taken out of the silo. This provides ample
opportunity for the toxin to escape to the
atmosphere. A light frost may even be helpful if
sorghum is harvested for silage since it will
allow the plant to dry down. The forage
sorghums often contain too high a level of
moisture when harvested direct (without wilting)
for silage.

Sorghums and other warm season annual grasses
that have received moderate to high rates of
nitrogen fertilizer and have been under drought
stress may contain toxic levels of nitrates. If
levels are high enough, nitrate poisoning can
occur. Drying or harvesting the plants for silage
does get rid of the nitrate. In some situations,
the potential for nitrate poisoning may be greater
than for prussic acid poisoning.

CGC

Castor Bean

Castor beans can sometimes be found in a
pasture. Yes, castor bean is poisonous. Castor
bean is a perennial in the tropics and subtropics,
but acts as an annual in much of the south
(where frost occurs). Found throughout the
Southeast; it is sometimes cultivated,
occasionally escapes and persists in pinelands,
waste places, and roadsides. I have seen it
growing in South Florida along roadsides and on
mounds of topsoil stockpiled by the highway
department.










four-sided. Also, coffee senna pods tend to be
straighter and shorter than those of sicklepod.
[The end of leaflets of coffee senna are pointed
whereas those of sicklepod tend to be rounded].
These plants are found throughout the south but
are more abundant on sandy soils of the coastal
plain, and are most abundant in cultivated fields,
roadsides, waste places and open pinelands.

Toxicity: The toxic principles have not been
clearly established. The seeds appear to exert
their toxicity upon the skeletal muscles, kidney,
and liver. The leaves and stem also contain
toxin, whether green or dry. Sicklepod is much
more prevalent but somewhat less toxic than
coffee senna. Animals can be poisoned by
consuming the plant in the field, in green chop,
in hay or if the seed is mixed in grain. Toxicity
has been observed in cattle. It should be
assumed that other animals are susceptible to the
effects of these plants.

Symptoms: Diarrhea is usually the first
symptom observed. Later, the animals go off
feed, appear lethargic, and tremors appear in the
hind legs, indicating muscle degeneration. As
the muscle degeneration progresses, the urine
becomes dark and coffee-colored and the animal
becomes recumbent and is unable to rise. Death
often occurs within 12 hours after the animal
goes down. There is no fever.

Treatment: Once animals become recumbent,
treatment is usually ineffective. Selenium and
Vitamin E injections have been used with
variable results.

CGC

Frosted Sorghums

Sorghums, sudangrass, and johnsongrass will
produce prussic acid after a frost or freeze. The
frosted forage will produce large quantities of
prussic acid when the plant cells break down in
the cow's rumen. This may cause prussic acid
(HCN) poisoning. If the forage is allowed to
dry for 3 to 6 days it should be safe to consume.
As the plants dry, the toxic compound will be
released to the atmosphere as a gas. In the fall,
remove animals from these pastures when frost


is eminent. [Pearl millet does not produce
prussic acid.]

Also do not allow animals to graze young
regrowth that may appear in south Florida after
the tops have been killed by a frost. At any time
during the growing season, always allow these
plants to reach a height of 18 to 24 inches before
grazing since the young plants have a higher
concentration of prussic acid, frost or no frost,
and can be dangerous.

Frosted sorghums can be harvested for silage.
The danger of prussic acid poisoning is
minimized since the forage is chopped coming
out of the field and then handled again when
taken out of the silo. This provides ample
opportunity for the toxin to escape to the
atmosphere. A light frost may even be helpful if
sorghum is harvested for silage since it will
allow the plant to dry down. The forage
sorghums often contain too high a level of
moisture when harvested direct (without wilting)
for silage.

Sorghums and other warm season annual grasses
that have received moderate to high rates of
nitrogen fertilizer and have been under drought
stress may contain toxic levels of nitrates. If
levels are high enough, nitrate poisoning can
occur. Drying or harvesting the plants for silage
does get rid of the nitrate. In some situations,
the potential for nitrate poisoning may be greater
than for prussic acid poisoning.

CGC

Castor Bean

Castor beans can sometimes be found in a
pasture. Yes, castor bean is poisonous. Castor
bean is a perennial in the tropics and subtropics,
but acts as an annual in much of the south
(where frost occurs). Found throughout the
Southeast; it is sometimes cultivated,
occasionally escapes and persists in pinelands,
waste places, and roadsides. I have seen it
growing in South Florida along roadsides and on
mounds of topsoil stockpiled by the highway
department.










Toxicity: The poisonous principle is a
phytotoxin called ricin. In the Southeast the
plant is commonly planted not only as an
ornamental but also in vegetable gardens to repel
moles. Horses are most susceptible to
poisoning, but all livestock and humans can be
affected. All parts of the plant are toxic,
especially the seeds. Toxicity is seen most often
in spring and summer.

Control: Mowing of very large plants may
provide all of the control that is needed
especially in the fall. If only a few plants are
present and if they are carrying seed, removal by
hand will prevent the spreading of seed. In the
spring as seed germinates and new plants
develop, commonly used pasture herbicides will
likely control small plants.

CGC

Grass Tetany in Cattle

Grass tetany sometimes called grass staggers or
hypomagnesemia, can be a serious problem in
Florida with cattle grazing small grain or
ryegrass pastures. The problem is usually
confined to lactating cows. The exact cause of
the disease is unknown, although it is always
associated with an imbalance in the mineral
components of blood serum, especially reduced
magnesium levels. In Florida, the disease is
more severe when cattle are grazing young
forage, particularly the first flush of growth
during December and January. Once the forage
becomes more mature, the likelihood of
problems occurring is reduced. The disease is
apt to appear under conditions of nutritional
stress. Placing cattle on winter pasture directly
after being on frosted or other low quality
pasture may cause such a nutritional stress.

The symptoms of hypomagnesemia closely
resemble those of milk fever or ketosis. These
include nervousness, lack of coordination,
muscular spasms, staggering and death. When
the disease is suspected, a veterinarian should be
called immediately to diagnose and to initiate
treatment. However, in beef herds, the
herdsman does not always have the opportunity
to observe the signs of the disease and affected


cattle may be found dead in the pasture.

Factors which have been associated with this
disease include low levels of magnesium (Mg)
and high protein and potassium levels in the
forage. Use dolomitic limestone, which contains
magnesium, to increase forage magnesium levels
if the level of soil magnesium is low. On soils
with a high pH level, magnesium can be
included with fertilizer materials. Excess
nitrogen in conjunction with high levels of
potassium fertilization tends to reduce the
magnesium level in most forage plants.
Consequently, these fertilizer elements should
not be applied in excess on temporary winter
pastures. Follow recommendations based on
soil test results.

Grass tetany can be prevented by feeding
mineral supplements that contain magnesium.
Commercial mineral mixtures containing 10-
15% magnesium are available for feeding during
periods of increased grass tetany probability.
Cattle need to consume 6-12 ounces/head/day of
this mineral. (For additional information on this
problem, see the publication Agronomy Facts
SS-AGR-64 "Grass Tetany in Cattle").

CGC

Tobacco Varieties for 2004

Many of the older varieties that have been
grown in Florida continued to produce excellent
yields and quality in the 2003 variety trials at
Live Oak. K 326, NC 55, NC 71, NC 72, NC
297, and Speight 168 were among the better
entries in the test. Black shank was not present
at this location. A new variety, NC 291,
performed well in this test as well as in other
states. NC 291 has high resistance to black
shank and also has resistance to potato virus-Y
and tobacco etch virus. RS 1410, another
variety new for 2003, also performed well. NC
102 will be available for the first time in 2004
and may be of interest to some Florida growers.
This variety has high resistance to black shank
and is resistant to tobacco mosaic virus. It has
resistance to some strains of potato virus-Y and
tobacco etch virus. It should have less stunting
from cucumber mosaic virus than other varieties










Toxicity: The poisonous principle is a
phytotoxin called ricin. In the Southeast the
plant is commonly planted not only as an
ornamental but also in vegetable gardens to repel
moles. Horses are most susceptible to
poisoning, but all livestock and humans can be
affected. All parts of the plant are toxic,
especially the seeds. Toxicity is seen most often
in spring and summer.

Control: Mowing of very large plants may
provide all of the control that is needed
especially in the fall. If only a few plants are
present and if they are carrying seed, removal by
hand will prevent the spreading of seed. In the
spring as seed germinates and new plants
develop, commonly used pasture herbicides will
likely control small plants.

CGC

Grass Tetany in Cattle

Grass tetany sometimes called grass staggers or
hypomagnesemia, can be a serious problem in
Florida with cattle grazing small grain or
ryegrass pastures. The problem is usually
confined to lactating cows. The exact cause of
the disease is unknown, although it is always
associated with an imbalance in the mineral
components of blood serum, especially reduced
magnesium levels. In Florida, the disease is
more severe when cattle are grazing young
forage, particularly the first flush of growth
during December and January. Once the forage
becomes more mature, the likelihood of
problems occurring is reduced. The disease is
apt to appear under conditions of nutritional
stress. Placing cattle on winter pasture directly
after being on frosted or other low quality
pasture may cause such a nutritional stress.

The symptoms of hypomagnesemia closely
resemble those of milk fever or ketosis. These
include nervousness, lack of coordination,
muscular spasms, staggering and death. When
the disease is suspected, a veterinarian should be
called immediately to diagnose and to initiate
treatment. However, in beef herds, the
herdsman does not always have the opportunity
to observe the signs of the disease and affected


cattle may be found dead in the pasture.

Factors which have been associated with this
disease include low levels of magnesium (Mg)
and high protein and potassium levels in the
forage. Use dolomitic limestone, which contains
magnesium, to increase forage magnesium levels
if the level of soil magnesium is low. On soils
with a high pH level, magnesium can be
included with fertilizer materials. Excess
nitrogen in conjunction with high levels of
potassium fertilization tends to reduce the
magnesium level in most forage plants.
Consequently, these fertilizer elements should
not be applied in excess on temporary winter
pastures. Follow recommendations based on
soil test results.

Grass tetany can be prevented by feeding
mineral supplements that contain magnesium.
Commercial mineral mixtures containing 10-
15% magnesium are available for feeding during
periods of increased grass tetany probability.
Cattle need to consume 6-12 ounces/head/day of
this mineral. (For additional information on this
problem, see the publication Agronomy Facts
SS-AGR-64 "Grass Tetany in Cattle").

CGC

Tobacco Varieties for 2004

Many of the older varieties that have been
grown in Florida continued to produce excellent
yields and quality in the 2003 variety trials at
Live Oak. K 326, NC 55, NC 71, NC 72, NC
297, and Speight 168 were among the better
entries in the test. Black shank was not present
at this location. A new variety, NC 291,
performed well in this test as well as in other
states. NC 291 has high resistance to black
shank and also has resistance to potato virus-Y
and tobacco etch virus. RS 1410, another
variety new for 2003, also performed well. NC
102 will be available for the first time in 2004
and may be of interest to some Florida growers.
This variety has high resistance to black shank
and is resistant to tobacco mosaic virus. It has
resistance to some strains of potato virus-Y and
tobacco etch virus. It should have less stunting
from cucumber mosaic virus than other varieties










although the leaf mosaic symptoms will still be
present. Other new varieties include NC 299,
NC 810, and Speight 210. These varieties also
have high resistance to black shank.

EBW

Tobacco Quota for 2004

The USDA will announce the 2004 flue-cured
tobacco quota by December 15, 2003. The
quota will be determined by three major
components. The first is the buying intentions
of the domestic manufacturers. They will report
their intentions by December 1. A second
component is the recent 3-year average export
level. The third component is determined by the
amount of tobacco in the loan program.
Although the amount of tobacco sold at auction
is only a fraction of that contracted, over 70
percent of non-contracted tobacco went into the
loan program. Unless there are substantial sales
of loan tobacco before December 15, the amount
of tobacco in loan could cause a reduction in the
quota. Finally, the Secretary of Agriculture can
increase or decrease the calculated quota by as
much as 3 percent. Most predictions are for
about a 15 percent reduction of quota for 2004
as compared to 2003.

EBW

Checking Tobacco Barns

The winter is a good time to test tobacco barns
for possible leaks in the heat exchanger. This
can be done by use of a CO2 meter. If the CO2
level in the barn increases when the burner
comes on, then it is possible that a crack has
developed in the heat exchanger. There is no
problem with increased levels of CO2 in the
barn, but is used as an indicator of nitrogen
gases that are also released during fuel
combustion. The nitrogen gases can react with
the tobacco to form nitrosamines, which is
undesirable. There are no inexpensive and
effective meters to measure the nitrogen
compounds, so the CO2 measurements are used.
A CO2 meter is available for county agents to
use to check barns.


EBW

Bahiagrass Rotation

Peanut yields after 2 years ofbahiagrass were
50% higher than peanuts after two years of
cotton in 2003. We have known for many years
that bahiagrass makes a good rotation for many
crops and reduces nematodes. Recent research at
the NFREC shows higher water infiltration,
higher soil water content down to 18 inches, and
better rooting depth of cotton grown after peanut
which was planted after bahiagrass than on
cotton grown after cotton which was planted
after peanut with no bahiagrass in the rotation.
These data indicate less need for irrigation and
better soil quality, less runoff and the possibility
of increasing soil organic matter from larger root
systems and top growth occurring in the
bahiagrass system. A business model of this
system can be found at
http://nfrec.ifas.ufl.edu/sodrotation/
sodrotation.htm This model is interactive and
actual numbers from individual farms can be
used to determine the profit of different
proportions of crops and livestock.

DLW

Deep Tillage in Continuous Row Crops

A common question asked by growers is "how
deep is deep enough for the deep tillage
operation to break the compaction layer and
obtain maximum benefit to crop yield". We
have several years of research that shows that
ripping under the row of non irrigated corn can
result in yield increases of as much as 50 bu/A
and 15 bu/A for soybeans. It was noted on
soybeans that when soils were ripped under the
row highest yields occurred as compared with
ripping different distances from the row. Wheat
yields have also been increased by 15 bu/A by
chisel plowing to a depth of 10 inches or deep
turning 10-12" deep as compared to harrowing.
Soils are normally compacted from a depth of 6"
to about 14" in typical fields in Florida. Fields
that have had winter grazing and have been
grazed over the winter when soils are typically
wet will have surface compaction in the top 3-4"
too. Therefore, to break the compaction layer,










although the leaf mosaic symptoms will still be
present. Other new varieties include NC 299,
NC 810, and Speight 210. These varieties also
have high resistance to black shank.

EBW

Tobacco Quota for 2004

The USDA will announce the 2004 flue-cured
tobacco quota by December 15, 2003. The
quota will be determined by three major
components. The first is the buying intentions
of the domestic manufacturers. They will report
their intentions by December 1. A second
component is the recent 3-year average export
level. The third component is determined by the
amount of tobacco in the loan program.
Although the amount of tobacco sold at auction
is only a fraction of that contracted, over 70
percent of non-contracted tobacco went into the
loan program. Unless there are substantial sales
of loan tobacco before December 15, the amount
of tobacco in loan could cause a reduction in the
quota. Finally, the Secretary of Agriculture can
increase or decrease the calculated quota by as
much as 3 percent. Most predictions are for
about a 15 percent reduction of quota for 2004
as compared to 2003.

EBW

Checking Tobacco Barns

The winter is a good time to test tobacco barns
for possible leaks in the heat exchanger. This
can be done by use of a CO2 meter. If the CO2
level in the barn increases when the burner
comes on, then it is possible that a crack has
developed in the heat exchanger. There is no
problem with increased levels of CO2 in the
barn, but is used as an indicator of nitrogen
gases that are also released during fuel
combustion. The nitrogen gases can react with
the tobacco to form nitrosamines, which is
undesirable. There are no inexpensive and
effective meters to measure the nitrogen
compounds, so the CO2 measurements are used.
A CO2 meter is available for county agents to
use to check barns.


EBW

Bahiagrass Rotation

Peanut yields after 2 years ofbahiagrass were
50% higher than peanuts after two years of
cotton in 2003. We have known for many years
that bahiagrass makes a good rotation for many
crops and reduces nematodes. Recent research at
the NFREC shows higher water infiltration,
higher soil water content down to 18 inches, and
better rooting depth of cotton grown after peanut
which was planted after bahiagrass than on
cotton grown after cotton which was planted
after peanut with no bahiagrass in the rotation.
These data indicate less need for irrigation and
better soil quality, less runoff and the possibility
of increasing soil organic matter from larger root
systems and top growth occurring in the
bahiagrass system. A business model of this
system can be found at
http://nfrec.ifas.ufl.edu/sodrotation/
sodrotation.htm This model is interactive and
actual numbers from individual farms can be
used to determine the profit of different
proportions of crops and livestock.

DLW

Deep Tillage in Continuous Row Crops

A common question asked by growers is "how
deep is deep enough for the deep tillage
operation to break the compaction layer and
obtain maximum benefit to crop yield". We
have several years of research that shows that
ripping under the row of non irrigated corn can
result in yield increases of as much as 50 bu/A
and 15 bu/A for soybeans. It was noted on
soybeans that when soils were ripped under the
row highest yields occurred as compared with
ripping different distances from the row. Wheat
yields have also been increased by 15 bu/A by
chisel plowing to a depth of 10 inches or deep
turning 10-12" deep as compared to harrowing.
Soils are normally compacted from a depth of 6"
to about 14" in typical fields in Florida. Fields
that have had winter grazing and have been
grazed over the winter when soils are typically
wet will have surface compaction in the top 3-4"
too. Therefore, to break the compaction layer,










although the leaf mosaic symptoms will still be
present. Other new varieties include NC 299,
NC 810, and Speight 210. These varieties also
have high resistance to black shank.

EBW

Tobacco Quota for 2004

The USDA will announce the 2004 flue-cured
tobacco quota by December 15, 2003. The
quota will be determined by three major
components. The first is the buying intentions
of the domestic manufacturers. They will report
their intentions by December 1. A second
component is the recent 3-year average export
level. The third component is determined by the
amount of tobacco in the loan program.
Although the amount of tobacco sold at auction
is only a fraction of that contracted, over 70
percent of non-contracted tobacco went into the
loan program. Unless there are substantial sales
of loan tobacco before December 15, the amount
of tobacco in loan could cause a reduction in the
quota. Finally, the Secretary of Agriculture can
increase or decrease the calculated quota by as
much as 3 percent. Most predictions are for
about a 15 percent reduction of quota for 2004
as compared to 2003.

EBW

Checking Tobacco Barns

The winter is a good time to test tobacco barns
for possible leaks in the heat exchanger. This
can be done by use of a CO2 meter. If the CO2
level in the barn increases when the burner
comes on, then it is possible that a crack has
developed in the heat exchanger. There is no
problem with increased levels of CO2 in the
barn, but is used as an indicator of nitrogen
gases that are also released during fuel
combustion. The nitrogen gases can react with
the tobacco to form nitrosamines, which is
undesirable. There are no inexpensive and
effective meters to measure the nitrogen
compounds, so the CO2 measurements are used.
A CO2 meter is available for county agents to
use to check barns.


EBW

Bahiagrass Rotation

Peanut yields after 2 years ofbahiagrass were
50% higher than peanuts after two years of
cotton in 2003. We have known for many years
that bahiagrass makes a good rotation for many
crops and reduces nematodes. Recent research at
the NFREC shows higher water infiltration,
higher soil water content down to 18 inches, and
better rooting depth of cotton grown after peanut
which was planted after bahiagrass than on
cotton grown after cotton which was planted
after peanut with no bahiagrass in the rotation.
These data indicate less need for irrigation and
better soil quality, less runoff and the possibility
of increasing soil organic matter from larger root
systems and top growth occurring in the
bahiagrass system. A business model of this
system can be found at
http://nfrec.ifas.ufl.edu/sodrotation/
sodrotation.htm This model is interactive and
actual numbers from individual farms can be
used to determine the profit of different
proportions of crops and livestock.

DLW

Deep Tillage in Continuous Row Crops

A common question asked by growers is "how
deep is deep enough for the deep tillage
operation to break the compaction layer and
obtain maximum benefit to crop yield". We
have several years of research that shows that
ripping under the row of non irrigated corn can
result in yield increases of as much as 50 bu/A
and 15 bu/A for soybeans. It was noted on
soybeans that when soils were ripped under the
row highest yields occurred as compared with
ripping different distances from the row. Wheat
yields have also been increased by 15 bu/A by
chisel plowing to a depth of 10 inches or deep
turning 10-12" deep as compared to harrowing.
Soils are normally compacted from a depth of 6"
to about 14" in typical fields in Florida. Fields
that have had winter grazing and have been
grazed over the winter when soils are typically
wet will have surface compaction in the top 3-4"
too. Therefore, to break the compaction layer,










although the leaf mosaic symptoms will still be
present. Other new varieties include NC 299,
NC 810, and Speight 210. These varieties also
have high resistance to black shank.

EBW

Tobacco Quota for 2004

The USDA will announce the 2004 flue-cured
tobacco quota by December 15, 2003. The
quota will be determined by three major
components. The first is the buying intentions
of the domestic manufacturers. They will report
their intentions by December 1. A second
component is the recent 3-year average export
level. The third component is determined by the
amount of tobacco in the loan program.
Although the amount of tobacco sold at auction
is only a fraction of that contracted, over 70
percent of non-contracted tobacco went into the
loan program. Unless there are substantial sales
of loan tobacco before December 15, the amount
of tobacco in loan could cause a reduction in the
quota. Finally, the Secretary of Agriculture can
increase or decrease the calculated quota by as
much as 3 percent. Most predictions are for
about a 15 percent reduction of quota for 2004
as compared to 2003.

EBW

Checking Tobacco Barns

The winter is a good time to test tobacco barns
for possible leaks in the heat exchanger. This
can be done by use of a CO2 meter. If the CO2
level in the barn increases when the burner
comes on, then it is possible that a crack has
developed in the heat exchanger. There is no
problem with increased levels of CO2 in the
barn, but is used as an indicator of nitrogen
gases that are also released during fuel
combustion. The nitrogen gases can react with
the tobacco to form nitrosamines, which is
undesirable. There are no inexpensive and
effective meters to measure the nitrogen
compounds, so the CO2 measurements are used.
A CO2 meter is available for county agents to
use to check barns.


EBW

Bahiagrass Rotation

Peanut yields after 2 years ofbahiagrass were
50% higher than peanuts after two years of
cotton in 2003. We have known for many years
that bahiagrass makes a good rotation for many
crops and reduces nematodes. Recent research at
the NFREC shows higher water infiltration,
higher soil water content down to 18 inches, and
better rooting depth of cotton grown after peanut
which was planted after bahiagrass than on
cotton grown after cotton which was planted
after peanut with no bahiagrass in the rotation.
These data indicate less need for irrigation and
better soil quality, less runoff and the possibility
of increasing soil organic matter from larger root
systems and top growth occurring in the
bahiagrass system. A business model of this
system can be found at
http://nfrec.ifas.ufl.edu/sodrotation/
sodrotation.htm This model is interactive and
actual numbers from individual farms can be
used to determine the profit of different
proportions of crops and livestock.

DLW

Deep Tillage in Continuous Row Crops

A common question asked by growers is "how
deep is deep enough for the deep tillage
operation to break the compaction layer and
obtain maximum benefit to crop yield". We
have several years of research that shows that
ripping under the row of non irrigated corn can
result in yield increases of as much as 50 bu/A
and 15 bu/A for soybeans. It was noted on
soybeans that when soils were ripped under the
row highest yields occurred as compared with
ripping different distances from the row. Wheat
yields have also been increased by 15 bu/A by
chisel plowing to a depth of 10 inches or deep
turning 10-12" deep as compared to harrowing.
Soils are normally compacted from a depth of 6"
to about 14" in typical fields in Florida. Fields
that have had winter grazing and have been
grazed over the winter when soils are typically
wet will have surface compaction in the top 3-4"
too. Therefore, to break the compaction layer,










we must do tillage operations down to a depth of
at least 14". Several years of research with a
paratill implement, which goes to a depth of
about 18 inches, show that it breaks through the
compaction layer. However, when compared to
strip tillage, which usually goes to a maximum
depth of 12", no yield advantage was found to
the deeper tillage. When both paratilling and
ripping under the row were done together in the
same plot of land, paratill first followed by
ripping under the row at planting, no yield
advantage was found above ripping under the
row alone. This occurs even when ripping under
the row does not completely break through the
compaction layer. With irrigated corn, no yield
increase was noted to in row deep tillage as
compared to using a harrow. This indicates that
the compaction layer is not a problem for crops
if water and nutrients are applied on a timely
basis and meets all plant needs in a more
shallow root system. However, due to irrigation
systems breaking down during periods of
highest need, it is still advisable to rip under the
row to increase rooting depth. The standard
practices of chisel plowing or turning or ripping
under the row with a subsoiler appear to give
just as good of results as using tillage
implements that will go 6-8" deeper (18" total
depth). Other good practices of rotation and
fertility management are necessary to aid the
practice of subsoiling under the row at planting
to obtain consistently good yields.


DLW


November Crop Report

The National Agricultural Statistics Service
estimated in November that the United States
would set a new record for corn yield per acre
and for total production in 2003. The average
corn yield estimate was increased from the
October estimate and stands at 143.2 bushels per
acre. The previous records for yield per acre
and total production was set in 1994. Soybean
estimates for November were lowered and
production is estimated to be 11 percent below
2002 and the lowest since 1996. Cotton
production was estimated to be 6 percent above
last year, and the estimated yield per acre of 722
pounds would be a record. Peanut yields for the
United States are estimated to be 3205 pounds
per acre which would be a new record. The
Florida average yield estimate for peanuts is
3000 pounds per acre. The average sugarcane
yield for Florida was estimated at 40 tons per
acre, while the US average was estimated to be
36.2 tons.

EBW

NEW Publications


SS-AGR-195


SS-AGR-196


SS-AGR-197


SS-AGR-198


Sugarcane Variety Census:
Florida 1998

Sugarcane Variety Census:
Florida 1999

Sugarcane Variety Census:
Florida 2000

Sugarcane Variety Census:
Florida 2001


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.
Prepared by: J. M. Bennett, Chairman; C. G. Chambliss, Extension Agronomist; G. E. MacDonald, Weed Researcher, M. A.
Mossler, Pest Management Information Specialist, E. B. Whitty, Extension Agronomist. D. L. Wright, Extension
Agronomist.










we must do tillage operations down to a depth of
at least 14". Several years of research with a
paratill implement, which goes to a depth of
about 18 inches, show that it breaks through the
compaction layer. However, when compared to
strip tillage, which usually goes to a maximum
depth of 12", no yield advantage was found to
the deeper tillage. When both paratilling and
ripping under the row were done together in the
same plot of land, paratill first followed by
ripping under the row at planting, no yield
advantage was found above ripping under the
row alone. This occurs even when ripping under
the row does not completely break through the
compaction layer. With irrigated corn, no yield
increase was noted to in row deep tillage as
compared to using a harrow. This indicates that
the compaction layer is not a problem for crops
if water and nutrients are applied on a timely
basis and meets all plant needs in a more
shallow root system. However, due to irrigation
systems breaking down during periods of
highest need, it is still advisable to rip under the
row to increase rooting depth. The standard
practices of chisel plowing or turning or ripping
under the row with a subsoiler appear to give
just as good of results as using tillage
implements that will go 6-8" deeper (18" total
depth). Other good practices of rotation and
fertility management are necessary to aid the
practice of subsoiling under the row at planting
to obtain consistently good yields.


DLW


November Crop Report

The National Agricultural Statistics Service
estimated in November that the United States
would set a new record for corn yield per acre
and for total production in 2003. The average
corn yield estimate was increased from the
October estimate and stands at 143.2 bushels per
acre. The previous records for yield per acre
and total production was set in 1994. Soybean
estimates for November were lowered and
production is estimated to be 11 percent below
2002 and the lowest since 1996. Cotton
production was estimated to be 6 percent above
last year, and the estimated yield per acre of 722
pounds would be a record. Peanut yields for the
United States are estimated to be 3205 pounds
per acre which would be a new record. The
Florida average yield estimate for peanuts is
3000 pounds per acre. The average sugarcane
yield for Florida was estimated at 40 tons per
acre, while the US average was estimated to be
36.2 tons.

EBW

NEW Publications


SS-AGR-195


SS-AGR-196


SS-AGR-197


SS-AGR-198


Sugarcane Variety Census:
Florida 1998

Sugarcane Variety Census:
Florida 1999

Sugarcane Variety Census:
Florida 2000

Sugarcane Variety Census:
Florida 2001


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.
Prepared by: J. M. Bennett, Chairman; C. G. Chambliss, Extension Agronomist; G. E. MacDonald, Weed Researcher, M. A.
Mossler, Pest Management Information Specialist, E. B. Whitty, Extension Agronomist. D. L. Wright, Extension
Agronomist.