in-crop-weather

State
Indiana Crop Weather

Week Ending Date  
August 22, 2005

Issue
IN-CW3405

                       Agricultural Summary

While many parts of the state received sufficient rainfall this past
week, there are still areas that are dry, according to the Indiana 
Field Office of USDA's National Agricultural Statistics Service. 
While the rain will help the soybean pods fill, many reporters feel 
it came too late to help a major part of the corn crop. There is 
expectation that corn yields will be affected. 

                        Field Crops Report

There were 5.1 days suitable for fieldwork. Corn condition is rated 41
percent good to excellent compared with 79 percent last year at this
time. Eighty-seven percent of the corn acreage has reached the dough
stage compared with 88 percent last year and 80 percent for the average.
By area, corn in dough is 85 percent complete in the north, 86 percent
complete in the central region and 93 percent complete in the south.
Forty- three percent of the corn acreage has reached the dent stage
compared with 49 percent last year and 38 percent for the average. 

Ninety-six percent of the soybean acreage is setting pods compared with
94 percent last year and 87 percent for the average. Soybean condition
is rated 52 percent good to excellent compared with 73 percent last
year. 

Third cutting of alfalfa hay is 67 percent complete compared with 62
percent last year and 63 percent for the average. 

Major activities during the week included spraying for aphids and spider
mites, attending the state fair, baling hay, cleaning grain bins,
hauling grain to market, mowing, working on harvest equipment, and
attending outlook meetings and field days. 

                Livestock, Pasture and Range Report

Pasture condition is rated 1 percent excellent, 17 percent good, 38
percent fair, 29 percent poor and 15 percent very poor. Livestock are in
mostly good condition. Feeding of hay continued on some livestock farms.

                    Crop Progress Table
-----------------------------------------------------
                     : This : Last : Last : 5-Year
     Crop            : Week : Week : Year :  Avg
-----------------------------------------------------
                             Percent
Corn in Dough           87     76     88     80
Corn in Dent            43     22     49     38
Corn Mature              2     NA      6      3
Soybeans Podding        96     90     94     87
Alfalfa Third Cutting   67     50     62     63

               Crop Condition Table
----------------------------------------------------------
                  : Very :      :      :      : Excel-
     Crop         : Poor : Poor : Fair : Good :  lent
---------------------------------------------------------- 
                             Percent
Corn                  6     17     36     36     5
Soybeans              4     12     32     45     7
Pasture              15     29     38     17     1

   Soil Moisture & Days Suitable
        for Fieldwork Table
--------------------------------------
              : This  : Last  : Last :
              : Week  : Week  : Year :
--------------------------------------
                      Percent
Topsoil
  Very Short     12      20      3
  Short          30      33     19
  Adequate       56      46     71
  Surplus         2       1      7
Subsoil
  Very Short     19      23      3
  Short          39      38     19
  Adequate       42      39     75
  Surplus         0       0      3
Days Suitable   5.1     5.7    5.0
Contact information
--Greg Preston, Director
--Jamie Price, Agricultural Statistician
  E-Mail Address: nass-in@nass.usda.gov
  http://www.nass.usda.gov/in/index.htm            
---------------------------------------------------------------------------

 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. Corn in IndianaSome 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, 2005), 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 was originally described by the University
of Illinois many years ago (Univ. of Illinois, 2005) and 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). 

EXAMPLE 

Let's say you counted 30 harvestable ears at the first sampling site.
Let's also assume that the average number of kernels per ear, based 
on sampling every 5th ear in the sampling row, was 511. The estimated
yield for that site would (30 x 511) divided by 90, which equals 
170 bu./ac. 

Repeat the procedure throughout field as many times as you deem to be
representative. Calculate the average yield for all the sites to
estimate the yield for the field. 

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. 

RELATED REFERENCES 

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 8/9/05]. 

Nielsen, R.L. (Bob). 2004a. Grain Fill Stages in Corn. Corny News
Network, Purdue Univ. Online at <www.kingcorn.org/news/articles.04/
GrainFill-0705.html>. [URL verified 8/9/05]. 

Nielsen, R.L. (Bob). 2004b. Yield Loss Potential During Grain Fill.
Corny News Network, Purdue Univ. Online at <www.kingcorn.org/news/
articles.04/GrainFillStress-0705.html>. [URL verified 8/9/05]. 

Nielsen, R.L. (Bob). 2005. Kernel Set Scuttlebutt. Corny News 
Network, Purdue Univ. Online at <www.kingcorn.org/news/articles.05/
KernelSet-0809.html>. [URL verified 8/9/05]. 

Thomison, Peter. 2005. Estimating Yield Losses in Drought Damaged 
Corn Fields. C.O.R.N. Newsletter, Ohio State Univ. Online at <http://
corn.osu.edu/story.php?setissue ID=96&storyID=571> [URL verified
8/9/05]. 

Univ. of Illinois. 2005. Estimating Corn Yields. (An Online 
Calculator). Illinois Agronomy Handbook. Online at <www.ag.uiuc.edu/
iah/index.php?ch=ch2/est_corn_yield.htm>. [URL verified 8/9/05]. 

For other Corny News Network articles, browse through the CNN
Archives at <www.kingcorn.org/news/archive.html>. For other 
information about corn, take a look at the Corn Growers' Guidebook 
at <www.kingcorn.org>. 

Bob Nielsen, Department of Agronomy, Purdue University, West 
Lafayette, IN.   

The INDIANA CROP & WEATHER REPORT (USPS 675-770), (ISSN 0442-817X) is
issued weekly April through November by the USDA, NASS, Indiana Field
Office, 1435 Win Hentschel Blvd,  Suite B105, West Lafayette IN 
47906-4145. Second Class postage paid at Lafayette IN. For 
information on subscribing, send request to above address. POSTMASTER:
Send address change to the USDA, NASS, Indiana Field Office, 1435 Win
Hentschel Blvd, Suite B105, West Lafayette IN 47906-4145. 
---------------------------------------------------------------------------------

             Weather Information Table

        Week ending Sunday August 21, 2005
-----------------------------------------------------
                | Past Week Weather Summary Data   
                |---------------------------------
 Station        |      Air      |            | Avg  
                |  Temperature  |  Precip.   |4 in.  
                |---------------|------------|Soil 
                |Hi |Lo |Avg|DFN|Total |Days |Temp 
----------------------------------------------------- 
Northwest (1)                                    
Chalmers_5W      90  60  74  +3   0.71     4      
Valparaiso_AP_I  85  57  73  +3   1.85     3     
Wanatah          86  55  72  +3   0.86     4   77
Wheatfield       87  59  73  +4   1.03     5     
Winamac          87  61  73  +4   0.23     3   73
North Central(2)                                 
Plymouth         86  59  73  +2   0.89     4      
South_Bend       84  57  73  +3   0.65     3     
Young_America    87  60  73  +3   0.21     2     
Northeast (3)                                    
Columbia_City    85  58  72  +3   0.23     3   78 
Fort_Wayne       87  59  73  +2   0.24     2     
West Central(4)                                  
Greencastle      90  59  74  +1   2.15     3      
Perrysville      99  58  75  +4   1.88     4   75
Spencer_Ag       91  62  75  +4   1.90     4     
Terre_Haute_AFB  91  59  76  +4   0.80     2     
W_Lafayette_6NW  89  59  74  +4   0.41     3   80
Central (5)                                      
Eagle_Creek_AP   88  61  75  +2   0.19     2      
Greenfield       90  60  74  +2   1.16     4     
Indianapolis_AP  90  63  76  +3   0.63     3     
Indianapolis_SE  89  61  74  +2   0.74     4     
Tipton_Ag        89  58  72  +3   0.92     4   77
East Central(6)                                  
Farmland         88  56  72  +3   1.58     4   71 
New_Castle       90  56  72  +3   1.45     5     
Southwest (7)                                    
Evansville       95  70  80  +5   2.14     5      
Freelandville    92  66  77  +4   1.84     6     
Shoals           92  65  77  +5   0.68     4     
Stendal          96  67  79  +4   0.98     6     
Vincennes_5NE    95  67  78  +5   1.42     4   78
South Central(8)                                 
Leavenworth      94  68  79  +6   1.37     5      
Oolitic          92  64  76  +4   1.56     5   79
Tell_City        96  70  81  +6   2.35     6     
Southeast (9)                                    
Brookville       93  62  76  +6   1.39     6      
Milan_5NE        93  62  76  +4   1.47     6     
Scottsburg       95  66  78  +5   2.80     6     
-----------------------------------------------------

      Weather Information Table (Continued)

      Week ending Sunday August 21, 2005
------------------------------------------------
                        Accumulation           
                --------------------------------
                      April 1, 2005 thru       
 Station                 August 21, 2005         
                 --------------------------------
                  Precipitation   |GDD Base 50oF
                 --------------------------------
                       |     |    |     |
                 Total | DFN |Days|Total| DFN   
-------------------------------------------------
Northwest (1)   |
Chalmers_5W     |13.27  -4.66  47   2564  +211
Valparaiso_AP_I |12.44  -6.12  43   2427  +283
Wanatah         |13.87  -4.24  51   2340  +288
Wheatfield      |18.43  +0.78  89   2437  +333
Winamac         |15.74  -2.17  53   2475  +305
North Central(2)| 
Plymouth        |12.77  -5.42  52   2387  +116
South_Bend      | 9.88  -7.56  50   2484  +351
Young_America   |16.99  -0.11  48   2459  +232
Northeast (3)   |
Columbia_City   |14.58  -2.73  51   2331  +298
Fort_Wayne      |12.88  -3.29  51   2452  +224
West Central(4) | 
Greencastle     |21.91  +1.59  43   2444   -63
Perrysville     |15.61  -3.73  46   2657  +314
Spencer_Ag      |19.92  -0.90  51   2480  +116
Terre_Haute_AFB |16.66  -2.68  45   2710  +212
W_Lafayette_6NW |12.00  -5.92  51   2525  +305
Central (5)     | 
Eagle_Creek_AP  |15.14  -3.08  47   2733  +256
Greenfield      |21.56  +1.48  57   2516  +145
Indianapolis_AP |15.09  -3.13  47   2736  +259
Indianapolis_SE |15.76  -3.16  49   2536   +76
Tipton_Ag       |19.12  +0.90  53   2342  +185
East Central(6) |
Farmland        |15.46  -2.25  50   2372  +267
New_Castle      |18.35  -1.02  46   2228   +74
Southwest (7)   |
Evansville      |14.70  -3.78  45   2977   +97
Freelandville   |16.96  -2.29  47   2800  +220
Shoals          |17.74  -3.15  57   2790  +298
Stendal         |16.61  -4.02  44   2957  +246
Vincennes_5NE   |21.82  +2.57  51   2899  +319
South Central(8)|
Leavenworth     |17.45  -3.94  46   2847  +364
Oolitic         |17.80  -2.30  52   2574  +191
Tell_City       |17.83  -3.25  38   3115  +364
Southeast (9)   |
Brookville      |16.49  -3.01  49   2636  +375
Milan_5NE       |18.58  -0.92  71   2595  +334
Scottsburg      |17.89  -1.92  53   2748  +183 
------------------------------------------------------------------
DFN = Departure From Normal (Using 1961-90 Normals Period).
GDD = Growing Degree Days.
Precipitation (Rainfall or melted snow/ice) in inches.
Precipitation Days = Days with precip of .01 inch or more.
Air Temperatures in Degrees Fahrenheit.

Copyright 2005:  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