Texas Cooperative Extension

ISSUES IN AGRICULTURE
The Newsletter About Integrated Pest Management and Agriculture for the El Paso Valley

Volume: 26
Issue: 12
Date: July 26, 2002

  
Sarah McKenzie Downing
EA-IPM
E-Mail: SMDowning@ag.tamu.edu
 
 



 
1030 N. Zaragosa Suite A
El Paso, Texas 79907
Phone: (915) 859-7725
Fax (915) 860-0331

Cotton:

The rain was very nice to see, but it hasn't made life easy for the scouts or myself. While it has been difficult getting in and out of the fields, there is very little activity going on. I am starting to see more bollworms than I have in the past. One field we scouted had around 6,000 small worms to an acre, which averages out to about 10% plants examined infested. Once bollworms reach populations of 5,000/acre or more treatment may be justified, however the presence of predators may keep populations in check. After bolls are present worm are calculated on a per acre basis to better include the number of plants/acre and possible economic loss into the decision making. This can be done with the following calculations:

       Worms, eggs, etc per acre =   # eggs,worms, etc. counted      X     # of plants/acre
                                         # of plants checked

To find the # of plants/acre:
        Plants/acre=           Row feet/acre       X     Plants counted
                             Row feet examined


        Row feet/acre=            522,720        
                           Row spacing in inches

Pecans:

Yellow pecan aphids (black margined) are starting to build up a little in some orchards. Treatment should be considered when populations reach 25+per compound leaf. Some suggested insecticides to control black margined aphids are: Chlorpyrifos (Lorsban 4E), Cypermethrin (Cymbush 3 E or Ammo 2.5E), or Esfenvalerate (Asana 1.9 EC). Note: Studies have shown that pyrethroid insecticides may flare aphids.

Growth Interval
Calender Days
 Accumulated heat units

Mean
Range
Planting to:

Stand establishment

First true leaf

Squaring

1/3 grown square

First bloom

Peak bloom

First open boll

95% mature bolls



7 5 -13

16 11 - 25

36 29 - 41

44 36 - 49

61 45 - 81

79 59 - 102

96 88 - 106

146 129 - 163



5 -13

11 - 25

29 - 41

36 - 49

45 - 81

59 - 102

88 - 106

129 - 163



78

526

1064

1641

2271

Boll development:

Fiber length established:

Fiber micronaire and strength determined:



First 18-45 days

Next 20-60 days

We will seek to provide reasonable accommodations for all persons with disabilities to any of our meetings. We request that you contact the Texas Agricultural Extension Service at (915) 859-7725 , one week in advance to advise us of the auxiliary aid or service you will require. Extension programs serve people of all ages regardless of socioeconomic level, race, color, sex, religion, disability, or national origin. The Texas A&M University System, U.S. Department of Agriculture, and the County Commissioners Courts of Texas Cooperating.

The information given herein is for educational purposes only. References to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Texas Agricultural Extension Service is implied.
1

 

COTTON As of July 25, 2002      
2002
2001
2000
January 1 (PBW)
2436.5
2348
2520
April 15 (Cotton)
1640.5
1614.5
1764

 

PECANS As of July 25, 2002      
2002
2001
2000
January 1
5321
5298
5695
March 15 (PNC)
4384
4543
4618.5

 

Texas Boll Weevil Update

Pink bollworm
Traps inspected: 3083
Average moths/trap: 0.5

Beet Armyworm
Traps inspected: 10
Average moths/trap: 2.7

Boll Weevil
No boll weevils have been caught to date.


Texas Cooperative Extension
1030 N. Zaragosa Suite A
El Paso, Texas 79907

Posted at this web site by:
texagnet Internet Services.

 
2