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. 17
THE INTEGRATED PEST MANAGEMENT NEWSLETTER
FOR THE LOWER ROLLING PLAINS
September 13, 2002

GROWING CONDITIONS

Cotton fields continue to open and are becoming more ready for harvest aids to be applied. A few fields are already defoliated and will probably be stripped within a week or so.

COTTON INSECTS

I would probably consider most if not all of the cotton fields safe from worms and all other pests except aphids. At this point, aphids will be more of a lint quality issue than a yield reducing factor. I think that the current condition of most of the crops is unfavorable to aphid populations. Thus, I do not expect to see many fields with aphid problems.

Extension trials have shown that as few as 15 aphids per leaf can produce enough honeydew to be a problem. However, as little as 1/4 inch of rainfall can wash this honeydew off and temporarily solve the problem. I have not seen honeydew become a problem in this part of West Texas, but there is always a first. Just keep an eye on your fields for the presence of aphids and you should be ok.

CROP TERMINATION

The latest question has been "When should I defoliate this field?" If using Cyclone or some other paraquat formulation, I would wait for more than 80% of the harvestable bolls to be open. I don't think you will lose much if you wait for 100% open bolls.

For other products you may treat the field as early as 60% open or when the highest harvestable boll is less than 4 nodes above the highest first position cracked boll. In these fields you may want to include a boll opener in the mix.

Mitchell County Crops Tour
Monday, September 16, 2002
8:30 at the C.C.Thompson Room

For More Information Contact
John Senter (728- 3111)

DEFOLIATION TRIALS

Defoliation Trials have been applied in Nolan and Mitchell Counties. Results have been erratic to say the least. I suggest that you check both sites to see what you think. The Nolan County field demonstration was applied way too early for good defoliation on 9-3-02, the cotton was ~ 10% open. This really tells a story when compared to the Mitchell County field which was applied the next day, on 9-4-02, with ~75% open bolls.

Many o f the products and tank mixes that did not work in the Nolan county field worked fine at 7 days after treatment in the Mitchell County field.

These fields can be located as follows:
Nolan County Harvest Aid Demo: West side of FM 608, 1 mile South of I-20.

Mitchell County Harvest Aid Demo: Southeast corner of CR 149 and CR 151/456. Or 3.25 miles East of FM 208 on FM 1982, then North 1 mile on CR 149.

These demos will remain marked for about 2 weeks.

Please Note the Change in the Normal Schedule for Tuesday and Wednesday.

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
2550
5/10
2419
5/20
2319
6/01
2167
6/10
2017
6/20
1822
7/01
1586
7/10
1434
7/20
1233
8/1
955
8/10
756
8/20
520
9/1
227
9/10
51
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

1. Date Rainfall (inches) Temp
(deg_F)
Max___Min 		Heat Units (DD60) Min Soil Temp (8-in) 10 Day Average Min Soil Temp Average Wind
Speed 		Max
Relative Humidity 		Min
Relative Humidity
09/05 0.01 91 69 20.0 84 86 5 74 33
09/06 0 93 67 20.0 83 86 4 69 24
09/07 0 90 67 18.5 84 86 7.2 76 32
09/08 0.75 85 69 17.0 64 86 7.2 91 54
09/09 0 83 68 15.5 80 86 5.3 95 55
09/10 0 85 69 17.0 79 86 4 96 45
09/11 0 86 66 16.0 78 86 5 93 36
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