in-crop-weather

State
Indiana Crop Weather

Week Ending Date  
July 25, 2004

Issue
IN-CW3004

Agricultural Summary

Crop reporters indicate conditions have been mostly favorable
for pollination of corn  this season, according to Indiana
Agricultural Statistics.  Cooler temperatures and timely
precipitation have helped.  Soybean plants are improving and
also making good progress as pods are forming on many of the
early planted fields.  Much needed rain helped development of
major crops and relieved dry soil conditions in most areas of
the state last week.  Many farmers were attending local county
fairs.  

Field Crops Report
     
There were 5.0 days suitable for fieldwork. Ninety-four percent
of the corn acreage has silked compared to 54 percent last year
and 76 percent for the average.  Twenty-four percent of the corn
acreage has reached the dough stage compared with 6 percent last
year and 13 percent for the average.  Corn condition improved
and is rated 77 percent good to excellent compared with 55
percent last year at this time. 

Seventy-seven percent of the soybean acreage is blooming
compared with 50 percent last year and 72 percent for the
average.  Thirty-six percent of the soybean acreage is setting
pods compared with 11 percent last year and 27 percent for the
average.  Soybean condition improved and is rated 72 percent
good to excellent compared with 51 percent last year at this
time.

Virtually all of the winter wheat acreage has been harvested
compared with 94 percent last year and 99 percent for the
average.  Second cutting of alfalfa hay is 85 percent complete
compared with 70 percent last year and 88 percent for the
average.

Other activities during the week were repairing equipment,
harvesting mint, scouting fields, mowing roads and pastures,
moving grain to market, hauling manure and taking care of
livestock.

Livestock, Pasture and Range Report

Pasture condition is rated 15 percent excellent, 59 percent
good, 20 percent fair, 5 percent poor and 1 percent very poor.
Livestock are in mostly good condition.  
 
                      Crop Progress Table
-----------------------------------------------------
                     : This :  Last :  Last : 5-Year
     Crop            : Week :  Week :  Year :  Avg
-----------------------------------------------------
                                 Percent
Corn Silked              94     82      54      76   
Corn in Dough            24     10       6      13   
Soybeans Blooming        77     67      50      72   
Soybeans Podding         36     22      11      27   
Alfalfa Second Cutting   85     68      70      88   
Winter Wheat Harvested  100     99      94      99   
                            
                    Crop Condition Table
-----------------------------------------------------------
                   : Very :      :      :      : Excel-
     Crop          : Poor : Poor : Fair : Good :  lent
-----------------------------------------------------------
                                Percent
Corn                  3      4     16     53      24    
Soybean               3      5     20     52      20    
Pasture               1      5     20     59      15    
               
   Soil Moisture & Days Suitable For Fieldwork Table
---------------------------------------------------
                 : This  : Last  :  Last :
                 : Week  : Week  :  Year :
---------------------------------------------------
                            Percent
Topsoil                            
  Very Short         2       1       1  
  Short             12      14       5  
  Adequate          79      76      65  
  Surplus            7       9      29  
Subsoil                            
  Very Short         1       1       1  
  Short             12      15       7  
  Adequate          82      78      66   
  Surplus            5       6      26
Days Suitable      5.0     5.0     4.5

Contact information
--Greg Preston, Director
--Bud Bever, Agricultural Statistician
  E-Mail Address: nass-in@nass.usda.gov
 http://www.nass.usda.gov/in/index.htm 
                
                     Crop Progress

Other Agricultural Comments And News

ESTIMATING CORN GRAIN YIELD PRIOR TO HARVEST

Fancy colored yield maps are fine for verifying grain yields at
the end of the harvest season, but bragging rights for the
highest corn yields are established earlier than that down at
the Main Street Cafe, on the corner of 5th and Earl.  Some
patrons of the cafe begin "eyeballing" their yields as soon as
their crops reach "roasting ear" stage.  Some of the guys there
are pretty good (or just plain lucky) at estimating yields prior
to harvest, while the estimates by others are not even close to
being within the proverbial ballpark.  Interestingly, they all
use the same procedure referred to as the Yield Component
Method.

Other pre-harvest yield prediction methods exist (Lauer, 2002;
Thomison, 2003), but the Yield Component Method is probably the
most popular because it can be used well ahead of harvest; as
early as the so-called "roasting ear" or milk (R3) stage of
kernel development.  Under "normal" conditions, the kernel milk
stage occurs about 18 to 22 days after pollination is complete
(Nielsen, 2004a).  Estimates made earlier in the kernel
development period risk being overly optimistic if subsequent
severe stresses cause unforeseen kernel abortion (Nielsen,
2004b).

The Yield Component Method is based on the premise that one can
estimate grain yield from estimates of the yield components that
constitute grain yield.  These yield components include number
of ears per acre, number of kernel rows per ear, number of
kernels per row, and weight per kernel.  The first three yield
components (ear number, kernel rows, kernels/row) are easily
measured in the field.

Final weight per kernel obviously cannot be measured until the
grain is mature (kernel black layer) and, realistically, at
harvest moisture.  Consequently, an average value for kernel
weight, expressed as 90,000 kernels per 56 lb bushel, is used as
a proverbial "fudge factor" in the yield estimation equation.
Crop uniformity greatly influences the accuracy of any yield
estimation technique.  The less uniform the field, the greater
the number of samples that should be taken to estimate yield for
the field.  There is a fine line between fairly sampling
disparate areas of the field and sampling randomly within a
field so as not to unfairly bias the yield estimates up or down.

1.  At each estimation site, measure off a length of row equal
    to 1/1000th acre.  For 30-inch (2.5 feet) rows, this equals
    17.4 feet.
   TIP: For other row spacings, divide 43,560 by the row spacing
  (in feet) and then divide that result by 1000 (e.g.,         
  [43,560/2.5]/1000 = 17.4 ft).
2. Count and record the number of ears on the plants in the
   1/1000th acre of row that you deem to be harvestable.
   TIP: Do not count dropped ears or those on severely lodged
   plants unless you are confident that the combine header will
   be able to retrieve them.
3. For every fifth ear in the sample row, record the number of 
   complete kernel rows per ear and average number of kernels
   per row.  Then multiply each ear's  row number by its number
   of kernels per row to calculate the total number of kernels
   for each ear.
  TIPS: Do not sample nubbins or obviously odd ears, unless they 
  fairly represent the sample area.  If row number changes from 
  butt to tip (e.g., pinched ears due to stress), estimate an  
  average row number for the ear.  Don't count the extreme butt
  or tip kernels, but rather begin and end where you perceive
  there are complete "rings" of kernels around the cob.  Do not 
  count aborted kernels.  If kernel numbers are uneven among the
  rows of an ear, estimate an average value for kernel number
  per row.
4. Calculate the average number of kernels per ear by summing
   the values for all the sampled ears and dividing by the
   number of ears.
   EXAMPLE: For five sample ears with 480, 500, 450, 600, and  
   525 kernels per ear, the average number of kernels per ear
   would be(480 + 500 + 450 + 600 +  525) divided by 5 = 511.
5. Estimate the yield for each site by multiplying the ear
   number by the average  number of kernels per ear, then
   dividing that result by 90.  The value of '90'  represents
   the average number of kernels (90,000) in a bushel of corn.
  TIP: Use a lower value (e.g., 80) if grain fill conditions
  have been excellent (larger kernels, fewer per bushel) or a
  larger value (e.g., 100) if grain fill conditions have been
  stressful (smaller kernels, more per bushel).

Remember that this method for estimating pre-harvest grain yield
in corn indeed provides only an estimate.  Since kernel size and
weight will vary depending on hybrid and environment, this yield
estimator should only be used to determine "ballpark" grain
yields.  Yield will be overestimated in a year with poor grain
fill conditions (e.g., low kernel size and weight from a drought
year) and underestimated in a year with excellent grain fill
conditions (e.g., larger kernel size and weight from non-stress
grain fill periods).  You can try to improve the yield
estimation for unusual grain fill conditions by adjusting the
estimation formula .  For example, if you believe that kernel
weight will be lower due to stress during grain fill, you may
elect to replace the value of "90" in the equation with "100" to
reflect the potential for smaller and lighter kernels (i.e.,
more kernels per 56 lb.  bushel).  Conversely, in a good crop
year, you may elect to replace the value of "90" in the equation
with "80" to reflect the potential for larger and heavier
kernels (i.e., fewer kernels per 56 lb.  bushel).

Recognize that the Yield Component Method for estimating corn
grain yield is probably only accurate within plus or minus 30
bushels of the actual yield.  Obviously, the more samples you
measure within a field, the more accurately you will "capture"
the variability of yield  throughout the field.  Use the yield
estimates obtained by this method for general planning purposes
only.

** Thanks to Emerson Nafziger, Univ. of Illinois, for suggested
revisions to the kernel number calculations.

Illinois Agronomy Handbook. 2004. Estimating Corn Yields.  (An
Online Calculator) Univ. of Illinois.  Online at
http://www.ag.uiuc.edu/iah/index.php?ch=ch2/est_corn_yield.htm
l&m=CFAR.  (URL verified 7/11/04, but temporarily off-line as of
7/18/04)

Lauer, Joe.  2002.  Methods for Calculating Corn Yield. 
Agronomy Advice, Univ. of Wisconsin-Madison.  Online at
http://corn.agronomy.wisc.edu/AAdvice/2002/A033.pdf.  (URL
verified 7/11/04)

Nielsen, R.L.  (Bob).  2004a.  Grain Fill Stages in Corn.  Corny
News Network, Purdue Univ.  Online at
http://www.kingcorn.org/news/articles.04/GrainFill-0705.html. 
(URL verified 7/18/04)

Nielsen, R.L.  (Bob).  2004b.  Yield Loss Potential During Grain
Fill.  Corny News Network, Purdue Univ.  Online at
http://www.kingcorn.org/news/articles.04/GrainFillStress-0705.
html.  (URL verified 7/18/04)

Thomison, Peter.  2003.  Estimating Corn Yields Prior to
Harvest.  C.O.R.N. Newsletter, Ohio State Univ. Online at
http://corn.osu.edu/archive/2003/aug/03-28.html#linkc.  (URL
verified 7/11/04).

                      Weather Information Table
                  Week ending Sunday July 25, 2004
                                                               
   -------------------------------------------------------------
                | Past Week Weather Summary Data   
                |---------------------------------
 Station        |      Air      |            | Avg  
                |  Temperature  |  Precip.   |4 in.  
                |---------------|------------|Soil 
                |Hi |Lo |Avg|DFN|Total |Days |Temp 
------------------------------------------------------------- 
Northwest (1)
Chalmers_5W      93  55  73  -2   0.16     1   72
Valparaiso_AP_I  91  53  71  -3   1.12     2     
Wanatah          91  51  71  -2   1.92     1   78
Wheatfield       91  55  72  -2   1.94     3     
Winamac          90  56  71  -2   1.53     3   76
North Central (2)
Plymouth         89  55  71  -4   1.83     2     
South_Bend       88  55  72  -2   1.44     2     
Young_America    89  56  72  -3   0.41     3     
Northeast (3)
Columbia_City    89  55  71  -2   2.21     4   75
Fort_Wayne       90  55  72  -3   2.52     3     
West Central (4)
Greencastle      88  55  72  -5   0.25     3     
Perrysville      87  55  72  -3   0.55     3   79
Spencer_Ag       87  57  72  -4   1.89     3     
Terre_Haute_AFB  91  58  74  -3   0.45     3     
W_Lafayette_6NW  90  51  72  -3   0.41     2   82
Central (5)
Eagle_Creek_AP   89  60  74  -3   2.22     2     
Greenfield       91  57  73  -3   1.35     2     
Indianapolis_AP  89  60  74  -2   3.58     2     
Indianapolis_SE  89  57  73  -4   2.71     2     
Tipton_Ag        90  55  71  -3   1.15     2   79
East Central (6)
Farmland         89  54  70  -3   1.25     2   71
New_Castle       88  52  69  -5   1.32     2     
Southwest (7)
Evansville       91  63  77  -3   1.53     3     
Freelandville    90  57  74  -4   0.90     3     
Shoals           90  60  74  -2   2.04     3     
Stendal          91  62  75  -3   0.69     3     
Vincennes_5NE    91  57  76  -1   0.37     2   77
South Central (8)
Leavenworth      89  62  74  -2   1.03     2     
Oolitic          89  60  73  -2   1.55     2   78
Tell_City        90  65  77  -1   0.44     1     
Southeast (9)
Brookville       92  58  73  -2   0.96     2     
Milan_5NE        90  58  73  -2   1.51     4     
Scottsburg       89  59  73  -4   0.35     2     
 
                                  
                      Weather Information Table
                  Week ending Sunday July 25, 2004
----------------|--------------------------------
                |        Accumulation           
                |--------------------------------
                |      April 1, 2004 thru       
 Station        |       July 25, 2004         
                |--------------------------------
                | Precipitation   |GDD Base 50oF
                |--------------------------------
                |      |     |    |     |
                |Total | DFN |Days|Total| DFN   
-------------------------------------------------
Northwest (1)
Chalmers_5W       20.54  +6.10  40  1744   -15
Valparaiso_AP_I   13.24  -2.08  45  1634   +57
Wanatah           13.13  -1.71  47  1543   +37
Wheatfield        25.62 +11.11  53  1613   +61
Winamac           17.08  +2.54  51  1671   +58
North Central (2)
Plymouth          16.18  +0.94  49  1608   -74
South_Bend        15.56  +1.31  50  1701  +141
Young_America     18.04  +4.05  44  1775  +127
Northeast (3)
Columbia_City     16.48  +2.15  54  1612  +123
Fort_Wayne        17.81  +4.61  49  1746  +108
West Central (4)
Greencastle       17.73  +1.27  48  1780   -88
Perrysville       15.83  +0.06  40  1949  +200
Spencer_Ag        21.44  +4.59  53  1912  +162
Terre_Haute_AFB   13.91  -2.06  44  2073  +207
W_Lafayette_6NW   19.20  +4.70  36  1792  +143
Central (5)
Eagle_Creek_AP    15.51  +0.68  48  1965  +118
Greenfield        16.71  +0.48  50  1870  +109
Indianapolis_AP   20.93  +6.10  46  2053  +206
Indianapolis_SE   17.21  +1.80  42  1887   +61
Tipton_Ag         15.30  +0.68  46  1717  +122
East Central (6)
Farmland          15.71  +1.16  47  1756  +205
New_Castle        17.62  +1.67  39  1560   -25
Southwest (7)
Evansville        19.05  +3.51  42  2349  +177
Freelandville     17.67  +1.59  44  2088  +158
Shoals            22.12  +4.75  48  2089  +234
Stendal           19.23  +2.00  45  2233  +203
Vincennes_5NE     18.37  +2.29  52  2179  +249
South Central (8)
Leavenworth       25.85  +8.32  51  2105  +255
Oolitic           21.05  +4.60  52  1969  +203
Tell_City         23.84  +6.41  45  2371  +315
Southeast (9)
Brookville        13.98  -1.83  41  1961  +299
Milan_5NE         20.17  +4.36  67  1944  +282
Scottsburg        28.82 +12.57  49  2051  +138
 
DFN = Departure From Normal (Using 1961-90 Normals Period).
GDD = Growing Degree Days.
Precipitation (Rainfall or melted snow/ice) and Pan Evap in
inches.
Precipitation Days = Days with precip of .01 inch or more.
Air Temperatures in Degrees Fahrenheit.

Copyright 2004:  Agricultural Weather Information Service, Inc.
All rights reserved.

       The above weather information is provided by AWIS, Inc.
For detailed ag weather forecasts and data visit the AWIS home page at
          www.awis.com or call toll free at 1-888-798-9955.