Arkansas Agriculture Newsletters
Arkansas Weekly Crop Report - July 19, 2006
Soybeans •
Cotton •
Rice •
Corn and Grain Sorghum
Soybeans
Arkansas Soybean Crop Situation - Trey Reaper
Not much has changed in the last week regarding crop condition.
Nearly everyone needs a good rain. Limited areas, particularly the
extreme northeast part of the state, have received good rainfall in
the last 10 days. Amounts in Clay County ranged from 3-5".
Unfortunately, the majority of the soybean production region is in
dire need of rainfall. The few days of "mild" temperatures last week
helped some, but the effects were short-lived due to a lack of soil
moisture. Early-planted irrigated fields look very good, with most
well into the R5 and R6 growth stages. Early-planted dryland fields
are beginning to show signs of leaf senescence and without rainfall
will mature rapidly. Over 50% of the crop has reached reproductive
growth. Late-planted and doublecropped fields are probably suffering
the most at this point. From the looks of most of these fields, it
appears they have not had significant rainfall since planting. Nodes
are severely stacked from drought stress, and charcoal rot is
showing up more every day.
Many growers who have June-planted fields are asking themselves
the same question regarding May-planted fields about this time last
month: "Do I try to water these small plants or just let them suffer
while waiting for rain?" Plants less than 12" tall can be very
difficult to water, particularly when planted flat. The long-range
forecast doesn’t look too good for rainfall, so many are to the
point of making the decision to flush across small plants. On
smaller plants, try to flush across the field as fast as possible to
minimize water stress. Border irrigation has also proven to be an
effective method to irrigating smaller plants as well. Growers who
utilized a bedded system have certainly realized the benefits in
being able to irrigate both early- and late-planted fields much
earlier than normal.
North SRVP (Trey Reaper): Some of the northern fields
received rainfall this past Monday. The Clay Co. field received over
3" of rain; however, this came only hours after the well was shut
off from its initial irrigation. The field is at R2 and plants
showing signs of possible phosphorus, zinc, and potassium
deficiencies are recovering slowly with the ease of drought stress.
The Randolph Co. field also received a good rain, its second in two
weeks. It is also at the R2 growth stage. Life isn’t as good in
Lawrence Co., as no significant rainfall has occurred in weeks. It
did receive a 0.5" shower on Tuesday night, so the third irrigation
will be delayed a day or two. The plants are well into R4 and the
field is holding up well. Downy mildew is noticeable across the
field despite dry conditions, but temperatures have been rather
mild. The Sebastian Co. field has a good pod load and has reached R5
but needs good rainfall to fill them out. The field looks extremely
good considering the lack of rainfall, and it obviously has a good
root system from the earlier planting date. The pivot in the Perry
North field continues to spin, and limited amounts of downy mildew
are noticeable as the plants approach R4. Irrigation will begin very
soon in the Perry South field, as that area has stopped receiving
timely rains. The Crittenden Co. field received showers both last
week and a few days ago; therefore, the herbicide application has
been delayed as well as the scheduled irrigation. The Phillips Co.
field is midway through R5 and will require two more irrigations if
no rainfall occurs. A very limited amount of SDS and frogeye was
observed but will obviously not affect the overall yield. The
Craighead Co. field looks excellent and received its sixth
irrigation late last week. The plants are approaching R5, and it
appears the Quadris has been effective in suppressing frogeye across
the field. The Mississippi Co. field received its first irrigation
late last week, and the plants are just beginning bloom. Other than
a few green and brown stinkbugs in the earlier-planted fields, no
insects warrant treatment.
South SRVP: (Matt Cordell) Most fields are in good shape;
however, a good rain would make things much better. Most fields
under irrigation are being watered every 7-10 days. Arkansas Co. was
in full bloom with nine vegetative nodes. On Friday, the field was
in need of irrigation. Some prickly sida and grass was observed as
well. In efforts to kill weeds before canopy closure, a 2 pt/A
application of glyphosate was recommended; irrigation was scheduled
to follow the next day. Plants in this field are growing well and
should canopy soon. In Ashley Co., plants were in R5/V12 growth
stage and scheduled to be irrigated over the weekend. Desha Co. is
in the V6 stage and not yet flowering. A new flush of broadleaf
signalgrass has appeared, and morningglories are still giving us
trouble, so an application of glyphosate + Classic was recommended.
A noticeable amount of bacterial pustule was also noted on first
true leaves and oldest trifoliates. Plants are in the V10 growth
stage in Drew Co. and are in full bloom. Reproductive growth stages
range from R2 to R4 in Jefferson County. Plants from the replant are
still a little behind the rest of the field. Insect numbers were
down and a good number of spiders were found when scouting. Damage
from an application of glyphosate + Synchrony is still evident in
stressed areas of the field. In Lafayette Co., the dryland field is
holding up well. Downy mildew is still hanging around in this field,
but is of no major concern. Plants have a nice pod load and seed is
beginning to fill. This field looks promising, but it’ll need a
couple showers to reach its full potential. No major insect pressure
has been detected with defoliation still under 5% in every field.
Some disease has been noted, but nothing has been a treatment level
this far.
Soybean Economics - Bob Stark - July 10, 2006
Average Arkansas cash soybean prices rose dramatically from $5.69
to $5.90 per bushel across the fifteen state markets as reported by
USDA-NASS for the July 3-July 7 trading week. These weekly averages
should be closely examined by market, since the market was closed on
Tuesday, July 4th , and six of the 15 markets ceased to quote
old crop prices after the holiday. The market prices had risen seven
cents on Monday from the previous Friday close and basically
maintained that level throughout the week to close at a Friday
statewide average of $5.90. The highest daily market price of this
past week was recorded at $6.04 on July 6 at the Helena and Osceola
markets. The lowest price was $5.63 on July 5 at Wynne.
Weekly averages for old crop Arkansas soybeans had been steadily
climbing from the large mid-May drop until the June 19-23 decline.
The bearish fundamentals cited by market analysts seemed to have
finally taken hold of the market, as the lower average prevailed for
another week. The current week’s price surge seemed to be fueled by
unfavorable weather conditions and falling USDA crop ratings. Time
will tell if a new trend is forming or the market will recover.
Soybean Insects - Gus Lorenz
We continue to receive calls on grasshoppers on the edges
of fields. With many areas of the state dry to moderately dry, this
is no surprise. In most cases grasshoppers are not small now - with
many one-half inch or larger - making control more difficult. The
threshold is the same for grasshoppers as for all defoliators: 40%
defoliation prebloom and 25% postbloom. If you are approaching the
threshold and grasshoppers are present, the pyrethroids may only do
a marginal job for control. In our studies, Lorsban has been shown
to be fairly effective for controlling grasshoppers. Acephate may
also be an option. In many cases the grasshoppers are along field
margins, and strip treating may be sufficient for control.
Stink bugs were reported last week on a few early-planted
soybeans in Lincoln County by John Smith, UAF graduate assistant.
John indicated many fields in the Taylorville area at or near
threshold on fields that were in the R5.5 growth stage. Remember,
the threshold is 9 per 25 sweeps. Many of the early-planted fields
are beginning to mature quickly and should be monitored closely for
developing stink bug populations in the coming weeks.
Soybean Rust Update - Amy Greenwalt
More soybean rust found in Louisiana since last week (on Kudzu).
No soybean rust has been detected in Arkansas to date.
National Soybean Rust Commentary (updated: 07/10/06)
Georgia officials reported today, July 10th, a confirmation of
soybean rust from a soybean sentinel plot in Decatur County. Decatur
County borders Gadsden County, Florida, where rust was found earlier
this year. This is the third report of soybean rust on this year's
soybeans. Soybean rust was found on kudzu in Iberia Parish,
Louisiana, on July 7th. This is the second find in Louisiana in
2006. Please consult the appropriate state commentary for more
information. Intensive scouting continues in soybean sentinel plots
especially in the south as soybeans reach reproductive growth
stages. Scouting also continues on kudzu patches. Rust has been
reported from 25 counties; five in Alabama, 12 in Florida, five in
Georgia, one in Texas, and two in Louisiana. Spore trapping
continues throughout the U.S. using both active and passive traps.
Any positive spore trap information does not imply infection has
taken place, and plant samples are used exclusively for indicating
positive rust occurrence as indicated on the soybean rust
observation map.
Disease Update - Michael Emerson
Downy Mildew
Downy mildew has been showing up in many of our soybean fields
across the state during the past two weeks. The recent showers,
heavy dews, and high humidity that we have had contributed to the
development of this disease. Downy mildew is caused by a fungal-like
pathogen known as Peronospora manshurica. It overwinters on
infected leaves and may be transmitted by wind, rain, and seeds that
have been infested.
Symptoms will often appear as irregularly shaped, small, light
green spots (not water-soaked) on the upper and lower leaf surfaces.
On the undersides of the leaves a small, tan colored turf of fungal
growth may also be observed within the lesion. Under severe
conditions downy mildew may cause early defoliation or yield
reduction; however, these yield reductions are often minimal if they
even occur at all. Currently we don’t have any research data to
suggest that a foliar applied fungicide would provide any economic
benefit for controlling this pathogen. Cultural practices such as
planting resistant varieties, crop rotation, and seed treatments are
suggested elsewhere as control options but seem unnecessary under
our conditions.
Frogeye Leaf Spot
Currently our weather conditions across the state have not
favored the development of frogeye leaf spot; however, there are a
few fields in northeast Arkansas that are at our current thresholds
and are being sprayed. Disease development is most favored by warm,
humid weather, while dry conditions tend to limit disease
development. Frogeye leaf spot is caused by the fungus Cercospora
sojina and is capable of causing significant yield loses under
favorable environments.
Symptoms will often appear on the leaves as circular to angular
spots that vary from less than 1 mm to 5 mm in diameter. Brown spots
that are surrounded by narrow red or dark reddish-brown margins are
often the first symptoms that people will see on the upper side of
the leaves. As the lesions age, the center will become more of an
ashy-grey to light brown color. Frogeye leaf spot may overwinter in
crop residue and is transmitted by wind or splashing rain within
fields. It may be moved about long distance by infected seeds.
Frogeye leaf spot is easily managed by planting resistant varieties,
treating seed that maybe infected, crop rotation, or use of labeled
fungicides on susceptible cultivars that are infected. Consult the
MP 154 for a complete list of fungicides that are currently labeled
on soybeans.
Please contact your local county Extension office for more
information on soybeans in Arkansas.
Cotton
Crop Status
(Bill
Robertson-
Extension Agronomist, Cotton)
As of July 10, the Arkansas Statistical Office
of the National Agricultural Statistics Service reported squaring at
99%, compared to 96% last week, 97% last year, and 95% averaged over
the last five years for this date. Boll set is estimated to be
occurring on 48% of the acreage, compared to 18% last week, 43% last
year, and 42% averaged over the last five. The condition of the
crop is 1% very poor, 8% poor, 32% fair, 45% good, and 14%
excellent. The latest acreage report released June 30 increased our
projected planted acreage from 1.1 to 1.15 million acres.
Scattered showers have been received in the northern half of the
state. Andy Vangilder, Extension agent in Clay county, reported
Tuesday evening that some areas have received in excess of 7 inches
of rainfall during the last round of rain. However, rainfall
distribution and amounts have been spotty. A good area-wide rain
this time of the year not only brings much needed moisture, but it
generally gives us a break in our high day and nighttime
temperatures. It appears that Mother Nature will help our weather
folks better predict our upcoming weather by delivering very hot and
humid conditions the remainder of this week and well into next.
This is not what we want or need for this crop.
Our crop is on a fast track toward cutout. NAWF values last week
were generally 7 to 9. However, the large squares in the terminals
indicated that new node development was at a very slow pace. As
expected, flowering is quickly moving up the plant. Many NAWF
values have dropped to 6 and 7 this week. Our current plant status,
coupled with the weather forecast, will push most fields to or past
cutout by the end of next week.
Supplemental nitrogen applications are being made in many
well-managed fields that are exhibiting high retention rates. I
would be very cautious in making soil-applied nitrogen applications
if cutout is expected in 10 to 12 days or less. Chances are great
that the additional fertility will not enhance boll set and fill in
that situation. It will likely come back to haunt us with increased
vegetative growth late in the season, making end of season
management decisions much more complicated. Foliar feeds, when
fertility needs exist, are a much better alternative as we approach
cutout.
Our crop is reaching cutout much quicker than expected. However,
our crop was planted much earlier than normal. In past years, I
have made supplemental soil applied nitrogen applications around
July 20 on May 1st planted cotton. This cotton would often cutout
the 5th to 10th of August. Many people this
season were finished planting by the first of May. Our
April-planted cotton will cutout by July 20. Timing of inputs based
on the calendar in a much different growing season like this one can
get you in trouble. Monitor NAWF values and retention values to
help make the best decisions we can to push this crop. Being timely
with irrigation and avoiding over-watering will likely be the
agronomic management decisions that will make the greatest
differences in the amount of cotton produced the way this season is
shaping up right now.
Cotton
Research Verification Program Update
(Frank
Groves-CRVP Coordinator)
Plants were generally at the 14- to 16-leaf
stage and are in the second week of flowering. Several verification
fields enjoyed a week where the rate of nodal development was high,
resulting in an increase in the NAWF value from the previous week.
Mepiquat chloride was applied at 12oz/A to
14oz/A across much of the program, with variable rate applications
being made when possible. Variable rate applications were typically
comprised of 16 to 14 oz/A in the heaviest biomass areas (zones 7
and 6), 10oz/A in zones 5 and 4, and no treatment in zones 3, 2 and
1.
Plant bug numbers are around one per five row
feet following treatment last week. Spider mite populations have
reached treatment level in the Phillips-Taylor field and Kelthane
will be applied at 32oz/A. Aphid numbers have built in South
Arkansas, but lady bug numbers of one per two feet (80% larvae) were
high enough to prevent applications.
A more detailed report of the Cotton Research
Verification Program can be found at
www.aragriculture.org/News/CRVP/. The CRVP
newsletter is typically updated every Friday throughout the season.
Cotton Insect
Pests
(Gus
Lorenz - Extension Entomologist)
Aphids are the big story this week.
Aphids have flared up in many fields, primarily throughout the
southern half of the state. Populations can be extremely high in
some fields, while in other fields they are present but not enough
to worry about.
We were able to get an efficacy trial out on a
field in Ashley County on the Bruce Bonds Farm. Our trial shows
fairly good control with most of the products. One thing to
remember: three days is not adequate time to evaluate efficacy of
Carbine. Carbine is not a quick knockdown material. While the
aphids take time to die, they are not feeding or causing further
damage. We expect to see even better numbers on control seven days
after treatment. While most of the products did fairly well, it’s
not what we have come to expect for aphid control. This indicates
that we may be developing some future control problems.
Aphids were collected from a field in Ashley
County that had recently been treated with a neonicitinoid. Jeff
Gore, USDA-ARS Entomologist at Stoneville, MS, compared them to a
control population at the station in Stoneville. The data shows
only 16% mortality in the Ashley County population, compared to 98%
in the control population that had not been treated with an
insecticide prior to the study. This data strongly suggests that
resistance to neonicitinoids may be a looming concern for us.
While we were in Ashley County, samples were
taken from a few fields and were sent to Dr. Steinkraus in
Fayetteville for aphid fungus evaluation. Three samples indicated
fungus was present at levels of 4%, 14%, and 37% infection. These
are the only confirmed fields with aphid infection in Arkansas.
We strongly encourage you to take samples before you pull the
trigger and spray aphids. Let’s save money and avoid
unnecessary applications if possible.
Bollworm trap counts spiked sharply over
the weekend. Egg and larval counts were high enough for us to begin
spraying our tests.
Spider Mites continue to be a problem in
many areas. I am getting several calls on tank mixing a pyrethroid,
a plant bug material, and a miticide. We’ve never done three-way
tank mixes. My initial impression is that this is not a good idea.
Remember, the plant bugs and worms are eating fruit and therefore
should be the primary target. Mites damage leaves and, if bad
enough, will cause defoliation. If they are this bad and you are
just now treating, chances are you waited too long. My advice is
get rid of the fruit feeders first and then treat the mites. Avoid
mixing too many chemicals at one time. Read labels carefully before
tank mixing.
Cotton
Economics
(Scott
Stiles and
Rob Hogan Extension Ag Economists)
Drought Outlook Positive for Cotton Prices?
On July 7, the Climate Prediction Center of
NOAA published an unscheduled update of the U.S. Seasonal Drought
Outlook. The Outlook may provide some insight into national weather
patterns through September. Based on current estimates there will
be very little change for the western half of Texas--particularly
the High Plains and Rolling Plains. This is not good news for Texas
cotton producers.
However, a continuation of current weather
patterns may lead to improvement in new crop cotton prices.
The recent USDA Planted Acreage report revealed
that the greatest increase in U.S. cotton acreage came from the
Southwest region. The National Ag Statistics Service estimated that
cotton acres increased by a combined 400,000 acres in Texas,
Oklahoma, and Kansas over the March 31 planting intentions number.
This increase brings the total cotton acreage for that region to 6.8
million acres - a decade high. 6.4 million of those acres are in
Texas.
On the surface, this acreage increase sounds
problematic for prices. However, much of the increase in cotton
acreage can be attributed to the abandonment of wheat. This year
Texas winter wheat acres totaled 5.6 million. Of that total only
1.4 million acres were harvested. The abandonment rate of the Texas
wheat crop was an astounding 75%. In search of an alternative,
Texans turned to cotton. Unfortunately, soil moisture content in
much of the state - particularly the western half--has not improved.
It is likely that many cotton acres will meet the same fate as did
wheat.
The big question on the minds of market
analysts is, "How much of the Texas crop will be abandoned?" Last
year it was 7.6%. That was low by Texas standards. In 1998,
abandonment reached 41.6%. The 10-year average for the state is
21.1%.
There were some rains over the weekend in the
northern and western sections of the Texas Panhandle. These rains
were welcomed. But it will obviously take a prolonged shift in the
current weather pattern to alleviate the drought conditions. The
current forecast for the Panhandle this week indicates a quick
return to hot and dry, with Lubbock seeing temperatures over 100F by
the end of the week.
The USDA will provide an estimate of yields and
abandonment on August 11.
Upcoming Meetings
2006 Field Days/Crop Tours
August 3 SEREC Rohwer Contact
Kelly Bryant
August 10 Clay County
August 24 Lon Mann CRS Marianna Contact
Claude Kennedy
August 25 Jefferson County
August 31 Judd Hill Contact
Fred Bourland
2006 County IPM Meetings
| Date |
County |
Location |
Time |
| July 25, 2006 |
Woodruff/Monroe |
Cotton Plant Gin |
Noon -
1:00 p.m. |
| August 1, 2006 |
Desha/Drew |
Tillar and Company |
11:30 a.m. - 1:00 p.m. |
For more information, contact your local Extension office.
Rice
Crop Condition and Status
Rice is beginning to reach heading across the state, with 6%
reported to be headed as of July 16 compared to 2% last week, 5% for
this time last year, and 10% for the 5-year average.
The latest estimate released today by the USDA is that Arkansas
planted approximately 1.471 million acres, 10% acres less than last
year’s record planted acreage of 1.643 million acres. This is an
increase of 60,000 acres from the March estimate. Long grain rice
acreage declined 12%, while medium grain increased by 8%. While
Missouri acreage remained flat compared to 2005, other southern
states declined sharply. Louisiana rice acreage declined by 32%,
Mississippi declined by 28%, and Texas declined by 26%. Overall,
the U.S. acreage declined by 14% with 2.9 million acres.
Based on preliminary estimates, the rice varieties and
distribution of acres include Wells (33.1%), Francis (11.2%), CL 131
(10.8%), Cheniere (10.1%), Bengal (7.9%) and CL 161 (7.3%).
Clearfield rice represents approximately 27% of the state’s rice
acreage (395,000 acres).
Temperatures ranged from 1 to 5 degrees above normal for the week ending July 16. Summer and the warm weather that goes with it has arrived. Several areas reported high temperatures above 100 degrees. The excessive heat is not good for rice that is beginning to head. The temperatures during late July and early August are as critical as any factor in determining yield potential in a given year. As of July 16, the USDA reported that 16% of the rice is in excellent condition, 49% good, 30% fair, 4% poor and 1% very poor. Overall, the crop has improved considerably compared to early in the year. However, the next 3-4 weeks are critical to making good yields. Rainfall accumulations for the week ending July 16 ranged from none at several locations to 3.86 inches at Keiser. The rainfall patterns were typical for this time of year with very scattered showers. The National Weather Service Drought Monitor indicates that much of Arkansas is in moderate to severe drought conditions. Soil moisture supplies are reported to be 29% very short, 40% short, 29% adequate, and 2% surplus. Rice DD50
The 2006 Rice DD50
program is now updated and on
the website. The link to access the program is http://dd50.uaex.edu/dd50Logon.asp.
You can find it under Agriculture/Rice/ Computer Programs. If you
have any questions, please feel free to contact us. There is also a
link to the DD50 Users Guide, which contains information about
different program options.
There are 10 new varieties and
hybrids added to the program for 2006. These include CL 131,
Jupiter, Presidio, Trenasse, Rice Tec CL XP 730, Rice Tec XP 721,
Rice Tec XP 728, Rice Tec XP 729, Rice Tec XP 731, Rice Tec XP 732.
This program can assist producers
and consultants organize management of rice fields and help plan
when decisions should be made. For producers or consultants
responsible for several acres, the program serves as a good
management tool to help coordinate many fields.
To enroll, the program can be
accessed either through the local County Extension Office or online
at the DD50 website. Information that is needed to enroll includes
the variety/hybrid, acres, and emergence date. If multiple fields
of the same variety have the same emergence date, please enter the
total acres represented by the program.
As you use the program, please
consider any changes that you think should be made to improve it and
forward your suggestions to us. We do appreciate your input. If
you have any questions, please contact Becky Bridges at bbridges@uaex.edu or Chuck Wilson at cwilson@uaex.edu. Stink Bugs are on the Prowl  Rice stink bug pressure is reported to be high in several
fields across the state. Some fields are above treatment threshold
at 75% panicle emergence, the time to begin scouting. High numbers
were reported in the wheat crop and have remained high. If left
unchecked, pecky rice and subsequent dockage at the mill will
result. It is important to control rice stink bugs as they
influence both yield and/or quality, depending on when the feeding
occurs.
Fields should be scouted by using a 15-inch sweep net making 10 sweeps of 180 degrees, with the top of the sweep net just at the top of the canopy. Fields should be treated when stink bug levels are above 5 bugs per 10 sweeps during the first 2 weeks after heading. The threshold changes to 10 bugs per 10 sweeps during the 3rd and 4th weeks after heading. It is important to scout in the morning hours while it is still fairly cool unless it is cloudy all day. During the heat of the day, stink bugs move down into the canopy of the rice plant and may not be caught in the sweep net. 
Labeled products for controlling rice stink bugs include include Methyl Parathion, Karate Z, Mustang Max, Prolex, Sevin, and Malathion. The products provide varying degrees of control and varying degrees of residual activity. Methyl parathion normally provides good control but has no residual activity. Sevin has historically had the longest residual but tends to be expensive. Upcoming Meetings and Events The University of Arkansas Rice Field Day will be held at the Rice Research and Extension Center near Stuttgart on August 9, 2006 beginning at 7:30 AM. Contact Dr. Chris Deren at 870-673-2661 for more information. The University of Arkansas will host a Field Day will be held at the Southeast Research and Extension Center near Rowher on August 3, 2006. Contact Dr. Kelly Bryant at 870-460-1091 for more information. The University of Arkansas will host a tour of the Rice Research Verification Program on July 25 2006 beginning at the Rice Research and Extension Center near Stuttgart at 7:00 am. For more information, contact Jeff Branson (501) 258-7234 or Stewart Runsick at (870) 718-1310. The University of Arkansas will host a rice consultant training on August 2, 2006 at our research location near Lake Hogue in Poinsett County beginning at 9:00 am. More information will be made available as the date becomes near. For more information contact Chuck Wilson at 501-258-0210.
County Field Days Eastern Clay County - August 10, 2006. Contact Andy Vanguilder, (870) 598-2246 Western Clay County - August 17, 2006. Contact Ron Baker, (870) 857-6875 Prairie, White, & Woodruff Tri-County Tour - August 8, 2006. Contact Hank Chaney (870) 998-2614 St. Francis County - August 22. Contact Mitch Crow (870) 261-1731 Cache River Valley Seed will be hosting their annual field day on August 16, 2006. For more information, contact Randy Woodard at (870) 477-5427.
Corn and Grain Sorghum Update According to the
latest Arkansas Agricultural Statistics Service report that was
released on July 17th, corn is developing ahead of last
year and previous years. 65% of the corn in the state is currently
in the dough stage, compared to 39% the previous week, 36% in 2005,
and 41% for the 5-year average. Overall the crop looks good, with
16% of the crop rated as being in excellent condition, 45% good, 29%
fair, 8% poor, and 2% rated as being in very poor condition. Crop
condition has continued to decline over the last few weeks as the
extreme heat and dry conditions continue to take their toll on the
crop. Grain sorghum
heading is nearing completion with 88% being reported headed. This
compares to 73% last week, 69% for last year, and 76% for the 5-year
average at this time. Overall crop condition is rated as 7% being
in excellent condition, 33% good, 44% fair, 14% poor, and 2% rated
as being in very poor condition. Much like corn, crop condition has
declined over the last couple of weeks as dry, hot weather
continues. Much of the state
is in need of rainfall currently. Good rains fell across the
northern tier of counties last week, with some reports of over 5
inches in localized areas. Statewide soil moisture has declined
this past week, and a majority of the state has not seen significant
rainfall in several weeks. Statewide soil moisture is rated as 29%
very short, 40% short, 29% adequate, and 2% surplus. Temperatures
of 100 degrees have been very common across the state this week.
This, combined with extremely dry conditions in much of the state,
has been taking its toll on all crops. The extended range weather
forecast is calling for slightly cooler temperatures over the
weekend with highs in the mid-90s but only slight chances of rain.
Irrigation
Termination for Corn
Jason Kelley, Wheat and Feed Grains
Extension Agronomist Many corn fields are currently nearing
irrigation termination. The goal with watering corn is to maintain
soil moisture until corn reaches physiological maturity (black
layer). This allows corn to maintain top yield potential without
spending excess money on watering.
One way to determine how close you are to
irrigation termination is to evaluate how far the starch layer has
developed in the kernel. The starch layer develops from the top of
the kernel and slowly moves down. Pick six or more representative
ears from different locations in the field. Break the ears in half
and pull kernels from the middle of the ear. Slice these kernels
lengthwise and evaluate how far the starch layer has progressed.
If the starch layer has developed more than halfway down the kernel
on a furrow- or flood- irrigated field and you have good moisture at
that time, then irrigation can be terminated. For
pivot-irrigated fields, we are not putting out as much water, so we
would like to see the starch layer develop at least ¾ of the way
down the kernel and have good soil moisture at that time before
irrigation is terminated. When in doubt, it is always better to
water one more time to ensure that maximum yield potential is
obtained. On fields that dry especially fast or hybrids with poor
stalk quality, the last watering can be critical to maintain yield
and prevent possible lodging issues at harvest.
The "dent" stage is not a good indicator of
when to stop irrigation. Hybrids dent differently, so some hybrids
may be near irrigation termination, while other may be a couple
weeks from irrigation termination. Stopping irrigation too early
can lead to reduced yields, primarily through reduced kernel
weights.
Corn and Grain Sorghum Verification
Jeremy Ross, Verification Coordinator Growth stages of the corn in Corn Research
Verification fields last week ranged from milk in Clay County to
dent in Desha County. All fields have been irrigated within the
last 5 to 7 days. Randolph, Clay, and Mississippi Counties have
received between 2 to 5 inches for rainfall in the last three days.
Irrigation termination will occur on the Desha County field this
week. The other corn fields will reach irrigation termination
(determined by 50% starch layer movement) within the next one to two
weeks. Corn earworm damage and some ear rots have increased from
last week. Trace amounts of common rust have been observed in the
Desha, Randolph, and Mississippi County corn fields, but due to the
warm weather, these amounts have not increased.
Both grain sorghum fields in Poinsett County
are progressing rapidly. The non-irrigated field is in the dough
stage and the irrigated field is in the milk stage. The irrigated
field is being irrigated every 10 to 14 days. Both fields were
scouted for sorghum midge, but none was found. Both fields will be
scouted until hard dough (in 2 weeks) for sorghum webworm and corn
earworm.
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