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Agronomy Notes April 2011 Volume 35:4 Features: Forage: Pasture Rest and Adequate Stocking Rate ...........Page 3 Y. Newman, Extension Forage Specialist ( ycnew@ufl.edu) ; J. Ferrell, Extension Weed Specialist (jferrell@ufl.edu); F. Fishel (weeddr@ufl.edu); D.C. Odero, Extension Weed Specialist (dcodero@ufl.edu); B. Seller s, Extension Weed Specialist (sellersb@ufl.edu); D. Wright, Extension Agronomist (wright@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. 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 rac e, color, sex, age, handicap or national origin. For information on obtaining other extension publications, contact your county Cooperative Extension Offi ce. Florida Cooperative Extension Service/Institute of Food and Agricultural Sciences/University of Florida/Millie Ferrer Chancy, Interim Dean. Crops: Corn Planting Date .April................................... Page 6 Dry Spring Leads to Early Kill of Cover Crops Page 6 Camelina as a Biofuel Crop................................ Page 7 Miscellaneous: Weeds and Pesticides: Postemergence Control of Annual Broadleaf Weeds in Sugarcane with Callisto .................Page 4 Pesticide Use Trends in the U.S.: Agricultural Pesticides ......................................................Page 5 Calendar ...........................................................Page 7

PAGE 2

2 Weed Science Dr. Jason Ferrell, Extension Weed Specialist jferrell@ufl.edu Dr. Brent Sellers, Extension Weed Specialist sellersb @ufl.edu Palmer amaranth is a tough weed that continues to march across the peanut belt. While imazapic (e.g. Cadre, Impose) was our main line of defense against this weed for many years, some populations are now resistant. In application. Palmer amaranth is a highly competitive weed that roots very deeply and pulls water from several feet away, provides deep shade to the peanut crop, and drops up to 400,000 seeds per plant. These facts indicate that Palmer can decimate a peanut field in a short amount of time and cause lasting effects due to the heavy seed rain. Peanut is particular sensitive to weed competition. In the absence of weeds, peanut can harvest a large amount of light energy and efficiently convert it to yield. But when weeds are present, the peanut enters a defensive mode and become more interested in survival than high yield. Even if the weeds are removed, the peanuts never recover and stay in the defensive mode for the rest of the season. Many states have labels that allow the use of Gramoxone Inteon in wiper type applicators. These applicators must wipe the herbicide solution on approximately 50% of the plant in order to be effective. In most cases this will not occur until late in the season when the weeds are quite tall. Although it can be important to use the wiper to remove Palmer and reduce their seed production, by this time peanut yield has already taken a hard hit. Controlling Palmer amaranth is a difficult proposition that requires a high level of pre season planning and dedication. It is essential to use a strong preemergence herbicide program followed by timely postemergence applications. If escapes occur, then the weed wipers should be employed to kill these plants before they make seed. difficult, if not impossible, to stop. Even if we eventually control these large plants, they have already done severe damage. Prevention is the key. Top: Palmer amaranth infestation. Bottom: Palmer amaranth removal. Photo by Jay Ferrel

PAGE 3

4 Forages Dr. Yoana Newman, Extension Forage Specialist ycnew @ufl.edu Pasture Rest and Adequate Stocking Rate The challenge for forage production is the management of pastures under the onset of warm season conditions when pastures have been affected by overstocking conditions during the winter. In some cases, in addition to overgrazing, the pastures may have had freeze damage or they may encounter early in the spring season pasture pests such as chinch bugs or mole crickets. Whichever the case, the road to recovery requires pasture rest and adequate stocking rate. There are many considerations for pasture recovery but the most critical include doing things in the right order weed control first, forage fertilization second, and next comes pasture rest and proper stocking rate. When plants are overgrazed, there is a reduction in the shoots and root development of the plant (see figure below). The root extension or elongation stops within 24 h after removal of 40 50% of the forage shoot mass, and some fine roots may also die soon after grazing. Resting pastures allows for leaf and root recovery. Providing enough rest from grazing defoliation allows the required re growth of leaves. First, the plant is able to start photosynthesis (process where the plant uses sunlight and converts it to green leaves). Over time the photosynthesis process increases, and the new leaf area continues light capture and conversion to carbohydrate (energy) that will be stored in the roots. The proper stocking rate is the one that leaves a good portion of the above ground basal forage (Photo below). In many cases this represents the lower 1/3 of the plant. Within sod type grasses, there are variations. Some will grow more upright than others (limpograss>stargrass and T 85 bermudagrass > coastal bermudagrass > bahiagrass). The rule to follow when managing stubble height for Florida grasses should be higher for limpograss compared to stargrass or Tifton 85, higher in stargrass and Tifton 85 compared to coastal, and higher in coastal compared to bahiagrass. It is fairly simple. Allow the grass to grow (by temporarily resting the pasture), pasture shoots and leaves will re grow, and the leaves will help recover the overgrazed root system. 3 Figure. Plant root growth as affected by grazing. Left : Not grazed. Middle : Proper grazing stubble. Right : Overgrazed plant. Photo adapted from: H.E. Dietz, RCS, 1989.

PAGE 4

4 Weed Science Dr. D. Calvin Odero, Extension Weed Specialist dcodero @ufl.edu Postemergence Control of Annual Broadleaf Weeds in Sugarcane with Callisto Annual broadleaf weeds need to be controlled in sugarcane because they negatively affect growth and development of the crop by competing for light, nutrients, water, and space. Common lambsquarters, common purslane, common ragweed, spiny amaranth, and smooth pigweed are the commonly occurring broadleaf weeds in sugarcane in the Everglades Agricultural Area (EAA). These weed species will emerge during the winter months and be prevalent in many fields in the spring if no control measures are carried out (Top picture). Atrazine has been the foundation for broadleaf weed control in sugarcane in the EAA for several years. Generally, up to 8 pints per acre of atrazine applied postemergence is used to control these weeds species. However, atrazine does not provide much residual activity because it is rapidly dissipated in the high organic matter soils of the EAA thus necessitating repeat herbicide applications. Currently, a low rate use herbicide Callisto is labeled for use in sugarcane to provide excellent postemergence control of many broadleaf weeds. Postemergence applications of Callisto can be over the top or post directed spray to the base of sugarcane at 3 fluid ounces per acre. This implies that it takes one gallon of Callisto compared to 31.5 gallons of atrazine to treat 42 acres. The low use rate of Callisto greatly reduces chemical storage, transportation, and handling. An addition of either crop oil concentrate (1% v/v), nonionic surfactant (0.25% v/v), or ammonium sulfate (8.5 lb/100 gallons) to the spray solution is required to maximize on weed control. Callisto can be safely tank mixed with a low rate of atrazine (1 quart per acre) to broaden the spectrum and efficacy of weed control. Herbicides such as Evik, Envoke, and Asulam can also be tank mixed with Callisto. Additionally, Callisto provides an effective tool for management of triazine and ALS resistant weed biotypes. Top : Common lambsquarters invading sugarcane field. Bottom : Postemergence control with Callisto. Photo by D. Calvin Odero

PAGE 5

5 Pesticides Dr. Fred Fishel, Pesticide Information Director weeddr @ufl.edu Pesticide Use Trends in the U.S.: Agricultural Pesticides The EPA, in cooperation with the USDA and FDA, is responsible for regulating the production and use of pesticides in the U.S. The most recent report, released in early 2011, provides data on volumes used and sales of pesticides from the latest EPA survey data available, 2006 2007. The data summary reported in this article is based upon EPA estimates. EPA does not have a program devoted specifically to estimating pesticide use; rather, they use the best available information from the public domain and proprietary sources. The data are approximate values and not statistically precise. The sources that EPA consults for compiling this information include the following: The Pesticide Data Center in the Biological and Economic Analysis Division of EPA's Office of Pesticide Programs; Several database services for compiling agricultural pesticide use data, including the USDA; and Others from private pesticide marketing research companies. U.S. agricultural pesticide expenditures totaled more than $7 billion in 2006 and 2007. The expenditure data separate broad classes of pesticides herbicides, insecticides, and fungicides and other pesticides. The "herbicide" data combine plant growth regulators (PGR) with them, while "fungicides and other" include sulfur, petroleum oil, nematicides, fumigants, and other miscellaneous conventional pesticides. Expenditures on herbicides/plant growth regulators accounted for the largest portion of total expenditures (more than 50% both years), followed by expenditures on insecticides, fungicides, and other pesticides, respectively. There was little change in relative quantities of pesticide expenditures for each class of pesticide both years. Total expenditures for agricultural pesticides as a whole were down in 2006 compared to 2007. U.S. pesticide amount used in 2006 and 2007 exceeded 600 million pounds of active ingredients both years. The largest portion of U.S. agricultural pesticides used each year was herbicides, followed by nematicides and fumigants, insecticides and miticides, fungicides, and other pesticides. Total volume of agricultural pesticides used was down in 2006 compared to 2007. The report also contains the most commonly used conventional agricultural pesticide active ingredients in 2007 and selected earlier years back to 2001. Glyphosate was the most used active ingredient in 2007, totaling between 180 million and 185 million pounds. Of the top twenty five active ingredients, thirteen are herbicides; three are fungicides; three are insecticides; five are fumigants; and one is a plant growth regulator. More details, including data tables, may be viewed in the following EDIS Document: http://edis.ifas.ufl.edu/pi176 For the full EPA report, see http://www.epa.gov/opp00001/pestsales/07pestsales/market_estimates06 07.pdf

PAGE 6

6 Corn Planting Date April Corn planting has been underway since early March. Corn usually has less disease and insect pressure when planted in March but can suffer from drought if not irrigated during silk and tassel period of mid May. Dryland corn often does better when planted in late April due to summer rains in June when silk and tassel period begins. Corn planted in late April will normally start silking in about 45 days while corn planted in early March takes 60 days or longer depending upon temperature. Growers with irrigation may want to plant early so that there is time for another summer crop such as soybean or a second crop of corn or summer grazing. Corn will be ready to harvest in late July or August leaving time for a second crop. The field needs to be utilized after harvest to prevent weeds from going to seed. Dry Spring Leads to Early Kill of Cover Crops Cover crops have value in producing nitrogen, controlling erosion, reducing evaporation losses from the soil surface, and moderating temperature for the subsequent crop. However, cover crops can dry out the soil for the spring crop if it is not killed timely when rainfall has been limited. Cover crops act as a reservoir for maintaining nutrients in the topsoil after it is killed and does increase water holding capacity of the soil if it is killed prior to dry periods. As the cover crop degrades it provides energy for microorganisms and releases carbon dioxide. Cation exchange capacity of the soil can be increased and soil structure improved by cover crops. It is important to kill out the cover crop at least 3 and preferably 4 or 5 weeks in advance of planting the summer crop to help eliminate soil insects and to keep soil from drying out. It is much easier to plant through dried cover crops than those that are wilted and tough when coulters slice through the soil ahead of the subsoil shank Crops Dr. David Wright, Extension Agronomist North Florida REC, Quincy wright@ufl.edu Non grazed small grain cover crop inside the cage killed 2 weeks earlier with Roundup. Photo by David Wright

PAGE 7

7 Camelina as a Biofuel Crop Little is known about camelina in Florida. Several producers throughout Florida planted acreage of the crop for oil. All of the fields seem to have survived the record cold in December and January when planted in October or November. One study at NFREC in Quincy planted during several days of 16 19 degree mornings had stand failure due to frost heaving of the soil. However, plantings made in January and February survived the cold weather and those plants that were blooming during the freeze appear to have successfully set pods. Mid October planted camelina will be harvested in late March this year and was probably delayed in maturing with the cold weather. More information will be available on the crop by the summer when yield data will be available. Crops Dr. David Wright, Extension Agronomist North Florida REC, Quincy wright@ufl.edu Camelina with pods late in the season which is about 4 weeks away from harvest. A few plants are still blooming. Photo by David Wright Calendar May 4 6 60th Annual Florida Beef Cattle Short Course, Gainesville, FL http://www.animal.ufl.edu/extension/beef/short.shtml May 17 18 65th Southern Pasture and Forage Crop Improvement Conference, Aiken, SC June 20 24 Marco Island, FL http://www.floridacattlemen.org/convention.html Jul. 3 9 Caribbean Food Crops Society meeting Two Mile Hill, St. Michael, Barbados,. http://www.cfcs2011barbados.org/ Oct. 3 5 Southeast Herbicide Applicator Conference Panama City Beach, FL http://conference. ifas.ufl.edu/sehac/index.html http://spfcic.okstate.edu


Agronomy notes
ALL VOLUMES CITATION THUMBNAILS PDF VIEWER PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00066352/00134
 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
Publication Date: April 2011
 Subjects
Subjects / Keywords: Crops and soils -- Florida   ( lcsh )
Crop yields -- Florida   ( lcsh )
Agriculture -- Florida   ( lcsh )
Agronomy -- Florida   ( lcsh )
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UF UNIVERSITY of
U FLORIDA
IFAS Extension


IL 0 0

A.bn om Nbe s-


Features:



Crops:

Corn F il,,i,, Date.A pri .................................. Page 6
Dry Spring Leads to Eary Kill of Cover Crops Page 6
Camelina as a Biofuel Crop.............................. Page 7


Forage:

Pasture Rest andAdequate Stocking Rate ...........Page 3

Weeds and Pesticides:

Don't Wait on the Weeds ................................Page 2
Postemeigence Control ofAnnual Broadleaf
Weeds in Sugarcane with Callisto .................Page 4
Pesticide Use Trends in the U.S.: Agrcultural
Pesticides ................................................Page 5


Miscellaneous:

Calendar ........... ..........................................Page 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/Millie Ferrer-Chancy, Interim Dean.


"Agronomy Notes" is prepared by: Maria Gallo, Chair and Y. Newman, Extension Forage Specialist . .. ..I. I .J. Ferrell, Extension Weed
Specialist |1. !!. II. ,i!I, .1 ii. F. Fishel . .11. !1. I. .1.. D.C. Odero, Extension Weed Specialist .I...I. ....1 ,!l. .1.. B. Sellers, Extension Weed
Specialist II. I .i..Ii i i. D. Wright, Extension Agronomist i, ,il, ii!i. .1., 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.







W eed Science Dr. Jason Ferrell, Extension Weed Specialist
jferrell@ufl.edu
Dr. Brent Sellers, Extension Weed Specialist
sellersb@ufl.edu



Don't Wait on the Weeds

Palmer amaranth is a tough weed that continues to march across the peanut belt. While imazapic (e.g. Cadre,
Impose) was our main line of defense against this weed for many years, some populations are now resistant. In
this case, we have very few options for postemergence if the weeds are greater than 4" tall. Considering that
Palmer amaranth can grow in excess of 1" per day, this is not a very wide window for timing a postemergence
application.

Palmer amaranth is a highly competitive weed that roots
very deeply and pulls water from several feet away,
provides deep shade to the peanut crop, and drops up to
400,000 seeds per plant. These facts indicate that Palmer
can decimate a peanut field in a short amount of time and
cause lasting effects due to the heavy seed rain.
Peanut is particular sensitive to weed competition. In the
absence of weeds, peanut can harvest a large amount of
light energy and efficiently convert it to yield. But when
weeds are present, the peanut enters a defensive mode
and become more interested in survival than high yield.

Even if the weeds are removed, the peanuts never recover
and stay in the defensive mode for the rest of the season.
Many states have labels that allow the use of Gramoxone
Inteon in wiper-type applicators. These applicators must
wipe the herbicide solution on approximately 50% of the
plant in order to be effective. In most cases this will not
occur until late in the season when the weeds are quite
tall. Although it can be important to use the wiper to
remove Palmer and reduce their seed production, by this
time peanut yield has already taken a hard hit.

Controlling Palmer amaranth is a difficult proposition
that requires a high level of pre-season planning and
dedication. It is essential to use a strong preemergence
herbicide program followed by timely postemergence
applications. If escapes occur, then the weed wipers
should be employed to kill these plants before they make
seed.
Top: Palmer amaranth infestation. Bottom: Palmer amaranth
removal. Photo by Jay Ferrel
Just remember, Palmer that is greater than 6" tall is
difficult, if not impossible, to stop. Even if we eventually
control these large plants, they have already done severe damage. Prevention is the key.






Forages Dr. Yoana Newman, Extension Forage Specialist
ymew@ufl.edu



Pasture Rest and Adequate Stocking Rate

The challenge for forage production is the management of pastures under the onset of warm season conditions when
pastures have been affected by overstocking conditions during the winter. In some cases, in addition to overgrazing,
the pastures may have had freeze damage or they may encounter early in the spring season pasture pests such as
chinch bugs or mole crickets. Whichever the case, the road to recovery requires pasture rest and adequate stocking
rate.

There are many considerations for pasture recovery but the most critical include doing things in the right order-
weed control first, forage fertilization second, and next comes pasture rest and proper stocking rate. When plants are
overgrazed, there is a reduction in the shoots and root development of the plant (see figure below). The root
extension or elongation stops within 24 h after removal of 40-50% of the forage shoot mass, and some fine roots
may also die soon after grazing. Resting pastures allows for leaf and root recovery. Providing enough rest from
grazing defoliation allows the required re-growth of leaves. First, the plant is able to start photosynthesis (process
where the plant uses sunlight and converts it to green leaves). Over time the photosynthesis process increases, and
the new leaf area continues light capture and conversion to carbohydrate (energy) that will be stored in the roots.

The proper stocking rate is the one that leaves a good portion of the above ground basal forage (Photo below). In
many cases this represents the lower 1/3 of the plant. Within sod type grasses, there are variations. Some will grow
more upright than others









------------------------- pas T-5bruredagtreassoot
(limpograss>stargrass and
T-85 bermudagrass >
coastal bermudagrass >
bahiagrass).


The rule to follow when
managing stubble height
for Florida grasses should
be higher for limpograss
S..: compared to stargrass or


Po' compared to coastal, and
S....higher in coastal
compared to bahiagrass.

It is fairly simple. Allow
the grass to grow (by
temporarily resting the
pasture), pasture shoots
Figure. Plant root growth as affected by grazing. and leaves will re-grow,
Left: Not grazed. Middle: Proper grazing stubble. Right: Overgrazed plant. and the leaves will help
recover the overgrazed
Photo adapted from: H.E. Dietz, RCS, 1989. root system.






W eed Science Dr. D. Calvin Odero, Extension Weed Specialist
dcodemroufl.edu


Postemergence Control of Annual Broadleaf Weeds in
Sugarcane with Callisto

Annual broadleaf weeds need to be controlled
in sugarcane because they negatively affect
growth and development of the crop by
competing for light, nutrients, water, and
space. Common lambsquarters, common
purslane, common ragweed, spiny amaranth,
and smooth pigweed are the commonly
occurring broadleaf weeds in sugarcane in the
Everglades Agricultural Area (EAA). These
weed species will emerge during the winter
months and be prevalent in many fields in the
spring if no control measures are carried out
(Top picture).

Atrazine has been the foundation for broadleaf
weed control in sugarcane in the EAA for
several years. Generally, up to 8 pints per acre
of atrazine applied postemergence is used to
control these weeds species. However, atrazine
does not provide much residual activity
because it is rapidly dissipated in the high
organic matter soils of the EAA thus
necessitating repeat herbicide applications.

Currently, a low rate use herbicide Callisto is
labeled for use in sugarcane to provide
excellent postemergence control of many
broadleaf weeds. Postemergence applications
of Callisto can be over-the-top or post-directed
spray to the base of sugarcane at 3 fluid ounces
per acre. This implies that it takes one gallon
of Callisto compared to 31.5 gallons of
atrazine to treat 42 acres. The low use rate of
Callisto greatly reduces chemical storage, Top: Common lambsquarters invading sugarcane field. Bottom: Postemer-
transportation, and handling. An addition of gence control with Callisto. Photo by D. Calvin Odero
either crop oil concentrate (1% v/v), nonionic
surfactant (0.25% v/v), or ammonium sulfate (8.5 lb/100 gallons) to the spray solution is required to maximize on
weed control.

Callisto can be safely tank mixed with a low rate of atrazine (1 quart per acre) to broaden the spectrum and
efficacy of weed control. Herbicides such as Evik, Envoke, and Asulam can also be tank mixed with Callisto.
Additionally, Callisto provides an effective tool for management of triazine and ALS resistant weed biotypes.


A






Pesticides Dr. Fred Fishel, Pesticide Information Director
weeddr(aufl.edu


Pesticide Use Trends in the U. S.: Agricultural Pesticides
The EPA, in cooperation with the USDA and FDA, is responsible for regulating the production and use of
pesticides in the U.S. The most recent report, released in early 2011, provides data on volumes used and sales of
pesticides from the latest EPA survey data available, 2006 2007.

The data summary reported in this article is based upon EPA estimates. EPA does not have a program
devoted specifically to estimating pesticide use; rather, they use the best available information from the public
domain and proprietary sources. The data are approximate values and not statistically precise. The sources that
EPA consults for compiling this information include the following:

The Pesticide Data Center in the Biological and Economic Analysis Division of EPA's Office of
Pesticide Programs;

Several database services for compiling agricultural pesticide use data, including the USDA; and
Others from private pesticide marketing research companies.

U.S. agricultural pesticide expenditures totaled more than $7 billion in 2006 and 2007. The expenditure
data separate broad classes of pesticides herbicides, insecticides, and fungicides and other pesticides. The
"herbicide" data combine plant growth regulators (PGR) with them, while "fungicides and other" include sulfur,
petroleum oil, nematicides, fumigants, and other miscellaneous conventional pesticides. Expenditures on
herbicides/plant growth regulators accounted for the largest portion of total expenditures (more than 50% both
years), followed by expenditures on insecticides, fungicides, and other pesticides, respectively. There was little
change in relative quantities of pesticide expenditures for each class of pesticide both years. Total expenditures for
agricultural pesticides as a whole were down in 2006 compared to 2007.

U.S. pesticide amount used in 2006 and 2007 exceeded 600 million pounds of active ingredients both
years. The largest portion of U.S. agricultural pesticides used each year was herbicides, followed by nematicides
and fumigants, insecticides and miticides, fungicides, and other pesticides. Total volume of agricultural pesticides
used was down in 2006 compared to 2007.

The report also contains the most commonly used conventional agricultural pesticide active ingredients in
2007 and selected earlier years back to 2001. Glyphosate was the most used active ingredient in 2007, totaling
between 180 million and 185 million pounds. Of the top twenty-five active ingredients, thirteen are herbicides;
three are fungicides; three are insecticides; five are fumigants; and one is a plant growth regulator.
More details, including data tables, may be viewed in the following EDIS Document: http://edis.ifas.ufl.edu/pil76.


For the full EPA report, see http://www.epa.gov/opp00001/pestsales/07pestsales/marketestimates06-07.pdf


M







Crops Dr. David Wright, Extension Agronomist
North Florida REC, Quing wright@ufl.edu



Corn Planting Date-April
Corn planting has been underway since early
March. Corn usually has less disease and
insect pressure when planted in March but
can suffer from drought if not irrigated
during silk and tassel period of mid May.
Dryland corn often does better when planted
in late April due to summer rains in June
when silk and tassel period begins. Corn
planted in late April will normally start
silking in about 45 days while corn planted
in early March takes 60 days or longer
depending upon temperature. Growers with
irrigation may want to plant early so that
there is time for another summer crop such
as soybean or a second crop of corn or
summer grazing. Corn will be ready to
harvest in late July or August leaving time for a second crop. The field needs to be utilized after harvest to
prevent weeds from going to seed.

Dry Spring Leads to Early Kill of Cover Crops
Cover crops have value in producing nitrogen, controlling erosion, reducing evaporation losses from the soil
surface, and moderating temperature for the subsequent crop. However, cover crops can dry out the soil for
the spring crop if it is not killed timely when
rainfall has been limited. Cover crops act as a
reservoir for maintaining nutrients in the
topsoil after it is killed and does increase
water holding capacity of the soil if it is killed
prior to dry periods. As the cover crop
degrades it provides energy for
microorganisms and releases carbon dioxide.
Cation exchange capacity of the soil can be
increased and soil structure improved by
cover crops. It is important to kill out the
cover crop at least 3 and preferably 4 or 5
weeks in advance of planting the summer crop
to help eliminate soil insects and to keep soil
from drying out. It is much easier to plant
through dried cover crops than those that are
wilted and tough when coulters slice through
the soil ahead of the subsoil shank .
Non grazed small grain cover crop inside the cage killed 2 weeks earlier
with Roundup.
Photo by David Wright






Crops Dr. David Wright, Extension Agronomist
North Florida REC, Quing wright@ufl.edu



Camelina as a Biofuel

Crop
Little is known about camelina in Florida.
Several producers throughout Florida b a
planted acreage of the crop for oil. All of p b D
the fields seem to have survived the record
cold in December and January when
planted in October or November. One
study at NFREC in Quincy planted during
several days of 16-19 degree mornings had
stand failure due to frost heaving of the
soil. However, plantings made in January
and February survived the cold weather
and those plants that were blooming during
the freeze appear to have successfully set
pods. Mid October planted camelina will
be harvested in late March this year and
was probably delayed in maturing with the
cold weather. More information will be Camelina with pods late in the season which is about 4 weeks away from har-
available on the crop by the summer when vest. A few plants are still blooming. Photo by David Wright
yield data will be available.



Calendar

To follow the link, press "Ctrl" and put cursor over link, and "click."

May 4-6 60th Annual Florida Beef Cattle Short Course, Gainesville, FL
http://www.animal.ufl.edu/extension/beef/short.shtml

May 17-18 65th Southern Pasture and Forage Crop Improvement Conference, Aiken, SC
http://spfcic.okstate.edu

June 20-24 2011 Florida Cattleman's Association Convention.. Marco Island, FL
http://www.floridacattlemen.org/convention.html

Jul. 3-9 Caribbean Food Crops Society meeting, Two Mile Hill, St. Michael, Barbados,.
http://www.cfcs201 lbarbados.org/

Oct. 3-5 Southeast Herbicide Applicator Conference, Panama City Beach, FL
http://conference. ifas.ufl.edu/sehac/index.html


H