Texas Agricultural Extension Service
The Texas A&M University System
Jones Mitchell
Nolan
Scurry
Stephen Biles
Extension Agent - IPM
P.O. Box 558
Sweetwater, TX 79556
Office: (915) 236-9011
Fax: (915) 236-9018
e-mail: biles-sp@tamu.edu
Website: http://nolan-ext.tamu.edu/ipm
Vol. 4, No. 9
THE INTEGRATED PEST MANAGEMENT NEWSLETTER
FOR THE LOWER ROLLING PLAINS
July 16, 2002

Growing Conditions

Cotton growing conditions continue to be very good. Additional rain fell in parts of the Lower Rolling Plains and soil moisture remains at levels adequate for higher cotton production. Fields range from pinhead square to early bloom. Insect activity is increasing. Populations of both pest and beneficial insects are on the rise.

Table 1. Pest and beneficial insect populations in the Lower Rolling Plains of Texas.

. Cotton
Fleahoppers		 Bollworms Aphids Beneficials
Conty # / 100 Plants
Jones 2-12 0-23 0-35 4-24
Mitchell 4-26 0-4 0-76 14-118
Nolan 2-8 0-33 0-27 6-26
Scurry 2-24 0-18 0-34 32-139

COTTON INSECTS

Aphids have been found in some fields in alarming numbers. Most of these fields have maintained lower populations of aphids for some time now and have higher levels of beneficials, mainly lady beetles adults and larvae and will not need treatment. These fields need to be watched to ensure that the beneficial insects do their part in reducing the aphid numbers.

If populations continue to exist above 50 aphids per leaf for more than one week, or rise to much levels above 100 aphids per leaf, treatment will be essential to prevent yield reductions.

Insecticides recommended for cotton aphid control include:
Bidrin at 6-8 oz./A; Centric 40WG at 2 oz./A; Intruder at 0.6oz./A; Provado 1.6F at 3.75oz./A; or Trimax at 1.5oz./A.

 

 Cotton fleahoppers continue to be found in the cotton fields at populations of 0-26 per 100 terminals, but are becoming less of an issue since the cotton is growing well and holding squares at acceptable levels. Dryland cotton fields that average more than 5-6 squares larger than a pinhead should be past the damage window for the cotton fleahopper unless additional square loss occurs by other factors such as bollworm damage.

Bollworms are being found in higher numbers that usual for this time of year. Cool temperatures and high humidity combined with low numbers of beneficials have increased survival of the small worms. Some fields are experiencing significant fruit loss. This can be a problem even in cotton that has not yet begun to bloom.

Before bloom, thresholds recommend that insecticide treatments should not be made if at all possible. However, treatment may be warranted where 15-25% of the green squares examined are worm damaged and small worms are present.

After bloom, treatment may be justified when counts average 5,000 to 10,000 or more small worms per acre, depending on scouting confidence. Consider aphids when making any insecticide sprays.

Producer Turn-Row Meetings
1 hour CEU available
All meetings begin at 8:30 a.m.

Monday

Tuesday Wednesday Thursday
15
U.A.P - Roscoe		 16
Producers COOP -Colorado City		 17
Snyder Farm and Ranch		 18
Corinth Gin

 

Educational programs conducted by the Texas Agricultural Extension Service serve people of all ages regardless of socioeconomic level, race, color, sex, religion, handicap or national origin. 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 Cooperative Extension Service is implied. We will seek to provice reasonable accomodations for all persons with disabilites for all extension programs. We request that you contact Mr. Stephen Biles (915/236-9011) as soon as possible to advise us of the auxiliary aid or service that your require.

___________________________________________________________________________________________________________

The Texas A&M University System, U.S. Department of Agriculture, and the Commissioners Courts of Texas Cooperating

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Table 2. Heat Units Accumulated from
Selected Dates Through July 2, 2001
From
Heat Units Accumulated
5/01
1234.5
5/10
1104
5/20
1103.5
6/01
851.5
6/10
702
6/20
506.5
7/01
270.5
Table 3. Accumulated Heat Units Required for Different Stages of Cotton
Growth Stage
From Emergence
From Previous Stage
1st True Leaf
16
16
Pin-head Square
455
439
Match-head Square
560
105
1/3 Grown Square
770
210
First Bloom
1064
294
First Open Boll
1641
577
95% Mature Bolls
2271
630

 
Table 4. Estimated Time Sequence of Growth and Development Stages in the Cotton Plant.
Planting Date
 --
1st Square 32 Days
--
1st White Bloom 23 Days
--
1st Open Boll 55 Days
--
30% Open 15 Days
--
60% Open 10 Days
--
85% Open 20 Days
--

 

Table 5. Projected Dates of Crop Growth Landmarks for Various Planting Dates Based on Table 4
Planting
Date
1st
Square
1st White
Bloom
1st Open
Boll
30%
Open
60%
Open
85%
Open
5/01
6/02
6/25
8/19
9/03
9/13
10/03
5/10
6/11
7/04
8/28
9/12
9/22
10/12
5/20
6/21
7/14
9/07
9/22
10/02
10/22
6/01
7/03
7/26
9/19
10/04
10/14
11/03
6/10
7/12
8/04
9/28
10/13
10/23
11/12
6/20
7/22
8/14
10/08
10/23
11/02
11/22
* Keep in mind that these dates are estimates, warmer and cooler temperatures will hasten and delay crop maturity, respectively.

 
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Lower Rolling Plains IPM Unit Weather Station Data
Located approximately 7.5 miles north of Roscoe, TX

Date
Rainfall
(inches)
Temp
(deg_F)
Heat
Units
(DD60)
Min
Soil
Temp
(8-in)
10 Day
Average
Min Soil
Temp
Average
Wind
Speed
Max
Releative
Humidity
Min
Relative
Humidity
Max
Min
07/09
0
93
69
21.0
79
80
4
85
33
07/10
0
92
69
20.5
80
80
5
89
30
07/11
0
95
69
22.0
82
80
5
85
28
07/12
0.4
92
68
20.0
83
80
4.1
79
33
07/13
0.11
89
69
19.0
80
80
4
88
40
07/14
0
92
67
19.5
79
80
4.2
90
28
07/15
0
90
65
17.5
80
80
6
86
36

 


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