in-crop-weather


State
Indiana Crop Weather

Week Ending Date
August 26, 2001

Issue
IN-CW3401



Agricultural Summary 

Farmers welcomed the rain last week.  This will help pod fill 
for soybeans and grain fill in later maturing corn fields. 
Heavy rain, strong winds and hail occurred in isolated areas.
Corn plants are advancing toward maturity and soybean plants 
are turning color in some fields.  Silage harvest continued 
and corn harvest has started in a few fields in southwestern 
Indiana.

						
Field Crops Report

There were 4.7 days suitable for fieldwork.  Corn condition
improved and is rated 72 percent good to excellent compared with
66 percent last week and 79 percent last year at this time. 
Thirteen percent of the corn acreage is mature compared with
8 percent last year and 5 percent for the average.  Seventy-one 
percent of the corn acreage is in the dent stage compared with
65 percent last year and 43 percent for the 5-year average.  
By area, 60 percent of the corn acreage is in the dent stage
in the north, 76 percent in the central regions and 83 percent 
in the south.  Soybean condition improved and is rated 67 percent 
good to excellent compared with 64 percent last week and 68 
percent last year.  Eight percent of the soybean acreage is 
shedding leaves compared with 9 percent last year and 5 percent
for the average.  Ninety-nine percent of the soybean acreage 
is setting pods compared with 97 percent last year and 89 
percent for the average.  Other activities during the week
included, preparing equipment for the fall harvest, baling hay, 
cleaning grain bins and care of livestock.

Livestock, Pasture and Range Report

Pasture condition is rated 4 percent excellent, 36 percent 
Pastures have improved. Third cutting of alfalfa hay is 92
percent complete compared with 84 percent last year.  Tobacco 
harvest is 25 percent complete compared with 20 percent for the 
average.  Livestock are in mostly good condition.


                          
                  Crop Progress Table
--------------------------------------------------------
                          : This : Last : Last : 5-Year
     Crop                 : Week : Week : Year :  Avg
--------------------------------------------------------
                                      Percent
Corn Dough                   97     93     97      85
Corn Dent                    71     50     65      43
Corn Mature                  13     NA      8       5
Soybeans Podding             99     98     97      89
Soybeans Shedding Lv          8      3      9       5
Alfalfa Third Cutting        92     84     84      NA




                    
                   Crop Condition Table
--------------------------------------------------------
                   : Very :      :      :      : Excel-
     Crop          : Poor : Poor : Fair : Good : lent
--------------------------------------------------------
                                  Percent
Corn                  2      6      20     53      19
Soybeans              2      7      24     51      16
Pasture               7     20      33     36       4



   Soil Moisture & Days Suitable For Fieldwork Table
-------------------------------------------------------
                   : This : Last : Last
                   : Week : Week : Year
-------------------------------------------------------
                           Percent
Topsoil
  Very Short          4      13     4
  Short              19      37    15
  Adequate           71      48    69
  Surplus             6       2    12
Subsoil
  Very Short         11      14     8
  Short              27      37    21
  Adequate           59      48    63
  Surplus             3       1     8
Days Suitable       4.7     6.2   5.2
Contact information
--Ralph W. Gann, State Statistician
--Bud Bever, Agricultural Statistician
  E-Mail Address: nass-in@nass.usda.gov
  http://www.nass.usda.gov/in/index.htm                     



Other Agricultural Comments And News


Sexual Dysfunction in the Corn Field 
                             
                              
- Pollination failure, especially on ear tips, is common in
  some fields
- Kernel abortion has also occurred in some fields
- Scattered kernel set due to pollination failure and kernel
  abortion is common in some fields
- Causes of sexual dysfunction are multiple

Deja vu or serendipity?  Several weeks ago I shared with
readers the ins and outs of the corn pollination process (P&C
Newsletter, 29 July) and the ways in which the pollination
process or subsequent grain filling period could go wrong (P&C
Newsletter, 11 Aug).  Since that time, quite a few reports
have come in describing pollination or grain filling problems
in fields around the state.

For the record, let's remember that pollination failure in
corn is caused by either lack of viable pollen, failure of
silks to emerge or non-receptive silks. Kernel abortion is
most likely to occur early in the kernel development process
when photosynthesis is restricted (cloudy days, leaf disease,
hail damage, severe N deficiency) or when photosynthate
availability to the kernels is limited (excessively warm
nights, competition with older kernels).

There seems to be a perception that one or two hybrids are
especially affected this year.  This may not be correct;
especially if folks are concentrating on walking fields of
those hybrids and ignoring fields of other hybrids.  Indeed,
I have observed serious tip fill problems and severely
scattered kernel set in more than one hybrid and from more
than one seed company.

Many fields exhibit some degree of pollination failure or
minor kernel abortion near the tip of the ears.  Typically,
one finds one to two inches of barren cob.  The bad news is
that the yield loss is about five bushels for every absent
'ring' of kernels around the cob.  The good news is that ear
length potential this year was often quite exceptional owing
to the generally favorable growing conditions prior to
flowering.

In such fields, ear length potential was so long that the tip
silks likely emerged after pollen shed was complete.  The
number of successfully developing kernels in these affected
fields is still 'normal' (from 30 to 35 kernels per row), even
though one or two inches of the ear tip are barren.  So, count
your kernels before you get all bent out of shape with the
poor tip fill in your fields.
                                   
In some fields, the poor tip fill includes some number of
aborted kernels in addition to simply blank portions of cob. 
Kernel abortion can be caused by any number of stresses,
including excessively warm nights  (low  to  mid -70's) 
during  silking  or severe moisture deficits.  Some areas
experienced several days of heavy overcast clouds during or
shortly after the pollination process.  Such excessive shading
or lack of intense sunlight soon after fertilization of the
ovary occurs can easily abort kernels.  Instances of all three
climatic conditions occurred in areas throughout the state
during pollination.  The cause of the abortion revolves around
a limited photosynthate supply to the younger developing
kernels. 

Unfortunately, the tip fill problems in other fields are not
related to exceptionally long ears or simply to warm  nights
or limited photosynthate supply.  Harvestable kernels per row
of ears in some fields sometimes number only 15 to 20. 
Moreover, varying degrees and frequencies of severely
scattered kernel set also exist in many fields.

In the fields I've walked, the more severe kernel set problems
are usually associated with significant levels of clipped
silks.  In most cases, it is unclear whether corn rootworm
(CRW) or Japanese beetles were the culprits, although goose-
necked plants in many of these fields were a good indication
that serious CRW larvae feeding injury to roots was a problem
earlier in the season.

The kernel set problems seem to be most prevalent in fields
where uneven plant development occurred due to uneven
emergence or uneven seedling growth.  In the fields I've
walked, severe silk clipping and resulting kernel set problems
were most evident in delayed plants than in 'normally'
developing plants.  Normal and delayed plants side-by-side
typically exhibit ears that are night and day different in the
success of pollination.  Plants in fields with more uniform
plant development exhibit less silk clipping in general and
fewer problems with severe scattered kernel set.

Uneven stands or plant development can be attributed to a)
uneven seedling emergence, b) injury from the Mother's Day
frost event, c) uneven plant development catalyzed by late
May/early June cold snap, d) injury from postemergence
herbicide applications, e) chilling injury from the mid-June
cold snap, f) chilling injury from the early July cold snap,
or g) injury from CRW larvae root feeding.  Any combination of
the above stresses could have set back plant development
unevenly throughout a field.  The delayed plants would silk
later and be more attractive to CRW or Japanese beetles than
would 'normal' plants.

The severe tip fill problems or scattered kernel set
associated with insect silk clipping are interesting because
few people, including yours truly, thought it was much of an
issue back in July when fields were pollinating.  Maybe we
were simply avoiding corn fields during the heat and humidity
and did not notice the problem.

There are also indications that earlier planted fields and
earlier maturity hybrids are less affected than later planted
fields or later maturity hybrids.  My own planting date study
at the Purdue Agronomy Farm illustrates the worst-case
scenario for CRW / Japanese beetle silk clipping in late-
planted corn.  Over many years of conducting planting date
studies, I have never seen such extensive CRW beetle feeding
on the silks in later-planted corn.

There are also a couple of weather-related issues that may
have played a role in setting up the corn plant for
pollination failure.  Above normal temperatures experienced in
some areas during pollen shed could have caused faster pollen
shed completion at the expense of later silk emergence from
tip ovules of long ears or delayed silk emergence due to
excessive CRW / Japanese beetle silk damage.

An admittedly farther stretch of imagination suggests that it
is possible that the one or two cold nights in early July
(remember the frost injury in low-lying muck fields)
interfered with normal pollen maturation, resulting in less
total pollen or some frequency of unviable or defective
pollen.  Similarly, the late May/early June cold snap may have
interfered with initiation of tassel branches and spikelets
due to the timing of the chilling injury with the initiation
of tassels occurring in corn that was at growth stages V5-V6. 
Interference with either tassel that was at development or
pollen maturation would have left the corn plant more
vulnerable to the effects of severe silk clipping by insects.

Bob Nielsen, Dept. of Agronomy, Purdue University.  This
article also contains pictures, which can be viewed at:
http://www.entm.purdue.edu/entomology/ext/targets/p&c/P&C200
1/P&C23_2001.pdf, pg. 3. 

 
                                  
 

                  Weather Information Table
     
               Week Ending Sunday August 26, 2001
---------------------------------------------------------------
                | Past Week Weather Summary Data   
                |---------------------------------
 Station        |      Air      |           | Avg  
                |  Temperature  |  Precip.  |4 in.  
                |---------------|-----------|Soil 
                |Hi |Lo |Avg|DFN|Total |Days|Temp 
--------------------------------------------------------------- 
Northwest (1)   |                                
Valparaiso_Ag   | 85  55  72  +3   0.88    5     
Wanatah         | 80  49  67  -3   3.73    5   75
Wheatfield      | 89  54  72  +4   1.61    4     
Winamac         | 88  54  71  +3   2.32    5   73
North Central(2)|                                
Logansport      | 94  55  71  +0   3.15    3     
Plymouth        | 86  52  70  -1   1.04    5     
South_Bend      | 85  55  72  +3   1.91    4     
Young_America   | 88  52  71  +1   2.81    3     
Northeast (3)   |                                
Bluffton        | 83  53  70  -1   2.30    3   71
Fort_Wayne      | 82  52  70  -1   2.51    4     
West Central (4)|                                
Crawfordsville  | 90  50  70  -2   1.38    4   73
Perrysville     | 90  52  72  +2   1.07    5   77
Terre_Haute_Ag  | 94  51  72  -1   0.38    3   76
W_Lafayette_6NW | 91  52  71  +2   1.87    4   74
Central (5)     |                                
Castleton       | 89  54  72  -1   0.59    3     
Greenfield      | 90  51  74  +4   1.77    4     
Greensburg      | 87  54  72  +2   0.89    6     
Indianapolis_AP | 92  55  74  +2   1.03    3     
Indianapolis_SE | 90  52  72  -1   1.25    4     
Tipton_Ag       | 88  50  70  +1   1.47    5   68
East Central (6)|                                
Farmland        | 84  48  69  +0   3.71    6   69
New_Castle      | 89  49  69  -2   1.23    2     
Southwest (7)   |                                
Dubois_Ag       | 93  53  74  +2   0.44    3   78
Evansville      | 92  58  76  +1   2.44    3     
Freelandville   | 91  57  73  +1   1.92    2     
Shoals          | 91  54  73  +1   0.42    2     
Vincennes_5NE   | 95  57  75  +3   1.57    3   73
South Central(8)|                                
Bloomington     | 91  55  73  +1   1.32    4     
Tell_City       | 93  59  77  +3   0.35    3     
Southeast (9)   |                                
Scottsburg      | 90  55  74  +1   0.97    4     
-------------------------------------------------------------
-------------------------------------------------------------
                |        Accumulation           
                |      April 1, 2001 thru       
 Station        |        August 26, 2001  
                |---------------------------------
                |Precipitation|  GDD Base 50oF   
                |-------------|-------------------
                | Total | DFN |Days|Total| DFN  
-------------------------------------------------------------     
Northwest (1)   |
Valparaiso_Ag   | 17.54  -1.65   70  2500  +258
Wanatah         | 21.40  +2.69   68  2302  +156
Wheatfield      | 18.00  -0.25   64  2495  +296
Winamac         | 20.76  +2.25   66  2474  +208
North Central(2)|
Logansport      | 26.10  +8.40   68  2504  +177
Plymouth        | 19.63  +0.89   65  2343   -31
South_Bend      | 19.09  +1.05   62  2486  +255
Young_America   | 22.27  +4.57   60  2551  +224
Northeast (3)   |
Bluffton        | 18.84  +1.06   65  2525  +137
Fort_Wayne      | 21.58  +4.86   63  2490  +160
West Central (4)|
Crawfordsville  | 18.56  -1.26   62  2461   -36
Perrysville     | 16.06  -3.88   58  2648  +201
Terre_Haute_Ag  | 23.84  +3.99   57  2868  +260
W_Lafayette_6NW | 15.80  -2.72   58  2628  +309
Central (5)     |
Castleton       | 21.79  +2.36   59  2709  +138
Greenfield      | 24.54  +3.89   63  2854  +376
Greensburg      | 22.14  +1.99   66  2816  +399
Indianapolis_AP | 20.52  +1.75   51  2862  +275
Indianapolis_SE | 19.27  -0.16   59  2623   +52
Tipton_Ag       | 17.77  -1.05   54  2425  +172
East Central (6)|
Farmland        | 22.74  +4.48   63  2462  +262
New_Castle      | 27.20  +7.28   61  2221   -31
Southwest (7)   |
Dubois_Ag       | 19.63  -1.99   56  2995  +370
Evansville      | 20.64  +1.71   57  3247  +242
Freelandville   | 19.55  -0.20   45  2972  +278
Shoals          | 20.18  -1.26   55  2828  +223
Vincennes_5NE   | 16.37  -3.38   42  3094  +400
South Central(8)|
Bloomington     | 19.75  -0.40   58  2830  +187
Tell_City       | 15.81  -5.87   41  3174  +299
Southeast (9)   |
Scottsburg      | 20.97  +0.61   70  2931  +251
-------------------------------------------------------------
DFN = Departure From Normal (Using 1961-90 Normals Period).
GDD = Growing Degree Days.
Precipitation (rain or melted snow/ice) in inches.
Precipitation Days = Days with precipitation of 0.01 inch or
more.
Air Temperatures in Degrees Fahrenheit. 

Copyright 2001:  AWIS, Inc.  All Rights Reserved.


   The above weather information is provided by AWIS, Inc.
 For detailed ag weather forecasts and data visit the AWIS
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