ROLL  COTTON DEVELOPMENT ADVISORY
                                    AUG 31, 2008 
PLANTING                                                               +/- normal
DATE+-------------------------------------------------------------------------+
    |            |   |     |      |         |           |           |         |
    |            |   |     |      |         |           |           |  3813v  |
2/1 **************************************************************************-2 days
    |            |   |     |      |         |           |           |   3746  |
2/15**************************************************************************-1 day
    |            |   |     |      |         |           |           |   v3633 |
3/1 ************************************************************************* -2 days
    |            |   |     |      |         |           |           |v  3500  |
3/15**********************************************************************  -2 days
    |            |   |     |      |         |           |        v  |         |
4/1 ****************************************************************** 3314 -2 days
    |            |   |     |      |         |           |           |         |
    |           Pin Sus   1st     1"    Pk. Bloom    Cut-Out    Terminate     |
    |          head  Sq. Flowr   Boll   +---+---+   +---+---+   +---+---+     |
    |                                   S   M   F   S   M   F   S   M   F     |
    +-------+-------+-------+-------+-------+-------+-------+-------+-------+-+
    0      400     800     1200    1600    2000    2400    2800    3200    3600
               HEAT UNITS ACCUMULATED FROM  PLANTING to AUG 30
     v = Heat Units on AUG 23;  S,M,F = Short, Medium, and Full Season Varieties


  HEAT UNITS 
--------------------------------
Heat Unit (HU) accumulation since Jan 1 = 3921;  Last year = 4168
HUs since Jan 1 are running about 4 days behind normal.
HU last week = 193


HISTORICAL STATISTICS 
--------------------------------
  Last Week : AUG 24 - AUG 30             This Week : AUG 31 - SEP 6
           HIGH  LOW DEWPT HUs  RAIN               HIGH  LOW DEWPT HUs
  Normal    105   76   64  196  ----       Normal   103   71   57  182
  Recorded  100   75   70  193  0.68         2007   108   77   62  203


ESTIMATED WATER USE 
--------------------------------
      Planting date :     2/1    2/15      3/1    3/15     4/1
Water Use (last week):    1.07"   1.14"    1.25"   1.39"   1.59"


HEAT STRESS LEVELS 
--------------------------------
Date     8/24   8/25   8/26   8/27   8/28   8/29   8/30  
Stress    L1     L1     ns     L1     L1     L1     ns  
Key :  ns = no stress;  L1 = Level 1 Stress;  L2 = Level 2 Stress 


WEATHER UPDATE 
--------------------------------
A weak storm system & trough of low pressure may produce a significant rain
event Sunday & Monday. Warm & dry air will follow this system & could signal
the end of the monsoon season. Expect sunny & warm conditions from Tuesday on
with much lower humidity. Boll maturity estimates can assist growers with de-
cisions pertaining to late season irrigations & crop termination and are avail-
able at at http://ag.arizona.edu/azmet/Boll_Maturity_2006.pdf. This will be the
final advisory for the 2008 season. We would like to thank the Arizona Cotton
Research & Protection Council for their funding assistance which helps keep this
program functional. Your feedback regarding the future of this program would be
most appreciated. Please email Paul Brown at pbrown@ag.arizona.edu.