2014-Progress Report
Individual Plant Treatments of Prickly Pear accompanied with Sendero
Site Locations:
Cooperators:
Authors:
Erath, Bosque and Parker Counties
Judy Lloyd, Bosque County Veterinary Clinic and Larry Walden
Property
James Jackson, Extension Program Specialist, Stephenville
Lonnie Jenschke, County Extension Agent, Erath County
Jon Green, County Extension Agent, Parker County
David Winkler, County Extension Agent, Bosque County
Summary
Multiple sites were established in 2014 to research the efficacy of Dow AgroSciences’ products
Surmount and Tordon 22K when mixed with Sendero. There were also treatments of PastureGard HL,
Grazon P+D, and GF-2766 put at each location. The primary objective of this study is to research the
effect Sendero will have when mixed with Surmount and Tordon 22K; however, this study was also
evaluating the effectiveness of PastureGard HL as a treatment option for prickly pear and comparing the
efficacy of GF-2766 to Grazon P+D. All treatments were mixed with MSO at a rate of 1.0% v/v.
Apparent mortality evaluations will be conducted at 60 days after treatment and one and two years
after treatment. Through evaluations, comparisons will be made to determine if the plots with Sendero
reached mortality at a quicker rate than those where Sendero was not added. It will also be recording
the results of GF-2766 and how it compares to Grazon P+D and the percentage mortality that
PastureGard HL delivers on prickly pear.
Objective
Prickly pear may interfere with movement and handling of livestock , with forage utilization, cause
serious livestock health problems, and compete with desirable forage plants. These plants are
extremely tolerant of drought and harsh conditions and are protected from grazing animals, to some
extent, by their spines. Prickly pear thrives in Central and the western half of Texas, both in rural
pastures and urban lots. They have the ability to grow and increase in abundance very rapidly. Once
prickly pear populations become very dense, control options are much more expensive and logistically
difficult. When this occurs, a ground broadcast treatment could be the most cost and time effective
method of control for prickly pear.
The herbicide recommended by the Brush Busters program for prickly pear control is Surmount, which
can take up to two 2 years to reach a high rate of mortality on the prickly pear. Tordon 22K is also an
effective herbicide on prickly pear. However, this treatment takes an extended period of time, as well,
to see any results. Sendero is Dow AgroSciences’ newest product for mesquite control. By using
Sendero on mesquite, it has been noted that it will have a yellowing effect on prickly pear shortly after
application. With the addition of Sendero to Surmount or Tordon 22K, we are examining the time that it
takes to reach mortality on prickly pear. The first objective of this project is to research the
effectiveness of Sendero on prickly pear when mixed with Surmount or Tordon 22K. The second
objective of this project is to look at the comparison of Grazon P+D to GF-2766 and the final objective of
this project is to look at PastureGard HL as a control option for prickly pear for non-private applicators
license holders. Should any of these options prove to be a viable option for prickly pear control, the
data generated by this project will be recommended as an addition to AgriLife Extension’s publication B1466 for faster results or other methods of controlling prickly pear.
Materials and Methods
Three sites were established in spring of 2014 in Erath, Bosque and Parker Counties. Each site
received all 7 treatments and were applied with backpack sprayer using an X8 conejet nozzle.
Hi-light spray indicator was added to each treatment to indicate the plants that were sprayed in
each plot. Each plot had a buffer of untreated plants between it and the next plot. Plots 1 and 2
in the Bosque county site were at half the rate due to human error and the total spray volume
per plot varied due to the amount of prickly pear at the location. Cost information is listed is
table 2 and varies depending on size and density of prickly pear plant in the plots. Herbicide
prices that were used to calculate this information are local prices and prices will vary
depending on supplier.
Environmental conditions on the day of application are provided in Table 1 and specific
treatment details are listed in Table 2.
Table 1. Environmental conditions on the day of application for prickly pear Individual plant treatment
trials established in 2014.
Site
Erath
Bosque
Parker
Date
4/29/14
5/2/14
6/5/14
Spray Time
8:00-11:30
7:15-11:00
9:00-12:00
Wind Speed/
Direction
8-12 mph/NW
4-8 mph/WNW
10-12 mph/SSE
Soil
Temp.
60⁰F
74⁰F
Air
Temp.
72⁰F
71⁰F
80⁰F
Soil Type/
Moisture
Purves/Med
Maloterre/Med
Windthrost/Med
RH
21%
24%
65%
Table 2. Herbicides, rates, and application data for Central Texas pricklypear Individual Plant Treatment
trials established in 2014. MSO at 1.0% v/v was added to all treatments
Treatment
No.
2014 Erath Co
1
2
3
Herbicide
Tordon
Surmount
Tordon
Sendero
4
Surmount
Sendero
5
PastureGardHL
6
Grazon P+D
7
GF-2766
2014 Bosque Co.
1
Tordon
2
Surmount
3
Tordon
Sendero
4
Surmount
Sendero
5
PastureGardHL
6
Grazon P+D
7
GF-2766
2014 Parker Co.
1
Tordon
2
Surmount
3
Tordon
Sendero
4
Surmount
Sendero
5
PastureGardHL
6
Grazon P+D
7
GF-2766
TSV/
plot
#
Plants
Treated
Area
Treated
Cost/
Plot
Cost/
Plant
IPT Rate
Material/
plot
1%
1%
0.5%
0.5%
0.5%
0.5%
1.0%
2.0%
1.35%
37.8 mL
37.8 mL
37.8 mL
37.8 mL
37.8 mL
37.8 mL
75.6 mL
151.0 mL
101 mL
29
27
43
0.74 A
0.17 A
0.19 A
$0.88
$0.75
$2.52
$0.03
$0.03
$0.06
36
0.14 A
$2.40
$0.07
32
36
34
0.29 A
0.22 A
0.06 A
$2.61
$1.75
$0.08
$0.05
0.32 A
0.16 A
0.14 A
$0.53
$0.93
$2.52
$0.01
$0.02
$0.06
51
0.21 A
$2.40
$0.05
2 gal
1 gal
1 gal
1.0%
2.0%
1.0%
37.8 mL
37.8 mL
37.8 mL
37.8 mL
37.8 mL
37.8 mL
75.6 mL
75.6 mL
50.7 mL
65
51
45
2 gal
0.5%
0.5%
0.5%
0.5%
0.5%
52
45
28
0.28 A
0.29 A
0.08 A
$2.61
$0.87
$0.05
$0.02
2 gal
2 gal
2 gal
1.0%
1.0%
0.5%
0.5%
0.5%
0.5%
1.0%
2.0%
1.35%
75 mL
75 mL
37 mL
37 mL
37 mL
37 mL
75 mL
151 mL
101 mL
33
45
27
0.12 A
0.09 A
0.03 A
$1.77
$1.50
$2.52
$0.05
$0.03
$0.09
55
0.30 A
$2.40
$0.04
43
40
39
0.14 A
0.07 A
0.08 A
$2.60
$1.75
$0.06
$0.04
1 gal
1 gal
2 gal
2 gal
2 gal
2 gal
2 gal
2 gal
2 gal
2 gal
2 gal
2 gal
2 gal
2 gal
Results and Discussion
The initial results of 2 and 4 months after treatments were applied indicate that Surmount tank
mixed with Sendero accelerate the rate at which prickly pear plants turn yellow. It has also
been noted that the PastureGard HL treatments at all sites have yellowed at a faster rate than
the other treatments applied at each location. The treatments of Grazon P+D and GF-2766
appear to have a slower rate of yellowing than the other treatments that were applied at all
locations. The Parker County site did not receive the 2 month after treatment evaluation,
however for the next year all plots will be evaluated every 90 days to analyze and compare the
speed of mortality between treatments. Table 3 indicates the results that have been collected
at the time the progress report was prepared.
Table 3: Results of plots 2 and 4 months after treatment Parker County did not receive and 2 month
after treatment evaluation.
Treatment #
1
2
3
4
5
6
7
Herbicide
Tordon
Surmount
Tordon+Sendero
Surmount+Sendero
PastureGard HL
Grazon P+D
GF-2766
Erath
20%
50%
40%
60%
50%
20%
25%
2 MAT
Bosque
30%
50%
50%
60%
50%
60%
40%
Parker
Erath
25%
55%
20%
60%
75%
40%
45%
4 MAT
Bosque
40%
55%
55%
65%
65%
20%
30%
Parker
25%
60%
55%
80%
60%
25%
30%
Acknowledgements
This project was supported by Dow AgroSciences, Erath, Bosque and Parker Counties and the
cooperating landowners.
Trade names of commercial products used in this report is included only for better understanding and clarity. Reference to
commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by
Texas AgriLife Extension Service and the Texas A&M University System is implied. Readers should realize that results from
one experiment do not represent conclusive evidence that the same response would occur where conditions vary.