Chloroplast haplotype networkÂ including admixed samples. (PDF 598Â kb

HyunJung Kim (3446192)

Janelle Jung (3446189)

Namrata Singh (1971532)

Anthony Greenberg (3446195)

Jeff Doyle (3446183)

Wricha Tyagi (248597)

Jong-Wook Chung (3446180)

Jennifer Kimball (76861)

Ruaraidh Hamilton (3446186)

Susan McCouch (14331)

Allen, Charles T.

Neeb, Charles

Multer, Warren

Texas A&amp;M Repository

Organizing an Area Wide, Producer Operated, Boll Weevil Diapause Control Program.

Texas A&M University

Texas Agricultural Extension Service
L-2431
Organizing An Area Wide,
Producer Operated,
Boll Weevil Diapause
Control Program
Charles T. Allen, Charles Neeb, and
Warren Multer *
The fall diapause program is an effective and rela-
tively inexpensive means of controlling boll weevils
and reducing yield losses in Texas. Such programs
have been very successful on the fringe areas of the
geographic range of the boll weevil (Glasscock,
Reagan and Upton Counties and the eastern and
southern boundaries of the Texas High Plains). The
success of these programs has prompted cotton
producers to consider implementing control
programs in other areas as well. This report outlines
some steps and considerations necessary for im-
plementation of a successful diapause boll weevil con-
trol program.
Objective of the Diapause
Control Program
The objective of the diapause control
program is to reduce overwintering weevil
populations to the extent that damaging in-
festations do not occur the following year,
or occur only occasionally on a few pro-
gram acres within the control zone
(geographic area within which the pro-
gram operates).
This eliminates or reduces costly, multi-
ple, in-season insecticide applications, and
it helps maintain natural parasites and
predators which aid in control of other in-
sect pests.
Why Diapause Control
Programs Work
A change occurs in boll weevil populations each
year in the late summer and fall. From late August
* EXtension entomologist, District Extension Director and Ex-
tension agent-entomology (pest management), The Texas
A&M University System.
through mid-November, an increasing proportion of
the emerging adult weevil population begins to store
fat in preparation for overwintering instead of ex-
pending their energy reproducing. They spend 2 to 3
weeks feeding and resting on cotton plants in
preparation for migration out of cotton fields into
protected sites for overwintering. Research has
shown that they must feed for at least 2 weeks in
-order to store enough fat to successfully overwinter
and become the breeding stock for hte next year's
population. During this period the weevil population
is vulnerable and can be controlled with insecticides.
Insecticide treatments made at intervals of 10 to 14
days and continuing until weevil food and breeding
sites are no ~onger available in cotton fields will sig-
nificantly reduce the overwintering weevil popula-
tion. .
Diapause Program Organization
Feasibility Study
To organize a successful producer operated, area-
wide diapause control program, a number of steps
should be taken. A task force should be organized to
conduct a feasability study on a diapause control pro-
gram. The task force should consist of area agricul-
ture representatives and it should include farmers,
agricultural lenders, agricultural chemical repre-
sentatives, consultants, Extension and research per-
sonnel, ginners, county commissioners and any other
persons involved in cotton production. This group
should carefully evaluate all aspects of a
boll weevil diapause program for the area.
These are some of the issues that should
be addressed in the feasibility study:
1. Establish the boundaries of the
diapause control zone and divide the con-
trol zone into proposed districts to
facilitate operation of the program.
2. Determine how the diapause con-
trol program integrates with other boll
weevil management techniques. These could
include uniform delayed planting, plow up
deadlines, use of early maturing varieties, in-
season insecticide treatments, etc.
3. Estimate the number of acres to be
treated and determine the trapping and field
scouting program needed to determine acres to be
treated each year.
4. Make a realistic estimate of program costs.
5. Investigate how to obtain funds (gins,
farmers, bank loans, etc.).
Texas Agricultural Extension Service • The Texas A&M University System • Zerle L. Carpenter, Director • College Station, Texas
6. Estimate the economic value of eliminating
boll weevil damage and the need for in-season in-
secticide treatments. This should include the
program's impact on other pests (impact of sprays
in fall and avoidance of sprays in the summer).
7. Evaluate the biological and ecological limita-
tions of the proposed diapause control program.
These may include abundance and location of
good overwintering habitat; isolation of program
acres from nearby untreated cotton; and the
presence of bodies of water, game preserves, com-
munities, etc. within the control zone which would
complicate area wide spraying.
8. Determine the extent of grower commitment
to the program. For program success, it is critical
that 95 percent or more (preferably 100 percent)
of the farmers within the control zone be com-
mitted to support the program for at least 3 years.
Although money from other sources may be ob-
tained, the feasibility study should determine
whether or not the growers have sufficient commit-
ment to spend their own money to conduct the ,
program.
When the fact finding has been completed, one or
a few members of the task force should be selected to
write a report on the findings of the feasibility study.
The report should be completed at least 6 months
(preferably a year) prior to initiation of the program
(contracting with aerial applicators, chemical
dealers, etc.).
Education of Area Clientele
Upon completion of the feasibility study, the
Texas Agricultural Extension Service and former
task force members should begin an educational ef-
fort. The first purpose of the educational effort is to
give growers in the proposed control zone training on
how the diapause program works. In addition, the
educational effort should explain and interpret the
feasibility study report to the growers. The second ob-
jective is to educate local residents who are not neces-
sarily involved in cotton production, but might be
concerned about the insecticide treatments.
Program Decision and Election of Directors
After the producers have been thoroughly edu-
cated about the program, the decision whether or not
to proceed with the program must be
made. This decision can be made
through a grower referendum or at an
area- wide grower meeting. It
should be made clear that the pro-
gram will operate for at least 3
years if a commitment to conduct
this program is made. The
feasability study report should be
reviewed prior to the decision. If
a decision is made to proceed with
the diapause control program, the
recommendations of the task
force given in the feasibility study
report regarding control zone
boundaries and districts should be
considered and accepted or
amended. A director should be
elected from each district in the
control zone. These directors will
form the Boll Weevil Diapause
Control Program Committee.
This committee will have the responsibility of or-
ganizing and conducting the Boll Weevil
Diapause Control Program. Directors should be
elected to serve terms of no more than 3 years. The
succession of directors should be arranged so that at
least half of the committee membership is always
made up of experienced directors. The initial commit-
tee of directors should be recognized leaders who
have demonstrated a strong commitment to the suc-
cess of the Boll Weevil Diapause Control Program.
Conducting The Program
Collecting Funds
The committee's first concern is to collect funds to
pay for the program. (The average cost in the St.
Lawrence area and High Plains boll weevil diapause
programs from 1986 to 1988 has been $2.66 and $3.07
per treated acre, respectively). The most convenient
way to collect funds is through a bale assessment at
gins within the diapause control zone. The limitation
is that assessments must be collected
at ginning time, the year before they
will be used. Another common way
to collect funds is by a per acre assess-
ment to the growers in the control
zone. The committee should collect
at least 20 percent more money than
they project will be needed in order
to cover unforseen expenses (such as
the need to spray more acres than ex-
pected). Excess money can be
rebated to growers or held for the
diapause program for the following year. If funds
run out before the program has been completed,
much of the desired weevil population reduction will
not be achieved.
Maps
Goo~ maps are very helpful in the conduct of a
diapause control program. 'In the Plains Cotton
Growers Assocation program maps are scaled to 1
inch = 1 mile (for scouting) and 1/2 inch = 1 mile
(for spraying). County ASCS offices, highway depart-
ments, county engineer offices and USDNSCS of-
fices are good sources of detailed maps.
Program Manager
In large programs it may be advis'able to hire a pro-
gram manager for the day-to-day conduct of the pro-
gram. His or her responsibilities include hiring of
scouts, supervision of field scouting and trapping,
working with the aerial applicator to calibrate spray
equipment, determining fields to be treated and
deciding when to spray and when to cancel treat-
ments, etc.
Determining The Infested Areas
Boll weevil pheromone traps should be in place
throughout the diapause control zone by early
August. Traps should be placed at densities of one
trap for 500 to 700 acres of cotton in the areas where
boll weevil populations are historically large. In less
heavily infested areas, trap densities can be gradually
decreased to one trap for 1,000 to 1,500 acres of cot-
ton. Funds should be allocated to pay salaries and
mileage for at least one part-time employee to
monitor traps for every 30,000 to 40,000 cotton acres.
Traps should be checked weekly from August
through October and a record should be kept of the
locations and weekly catches of each trap.
Field scouting should be conducted from late
August through about September 25. Several fields
should be checked in each area of the control
zone.
In each field four sites should be check-
ed. Two of these sites should be selected
at random and two should be deliberate-
ly selected in areas where weevil popula-
tions are most likely to be found. Field
scouts should move at least 50 to 60 feet
into fields. Sections of row (two at each
s.ite) that measure 8 feet 11/2 inch,
should be carefully examined for adult
weavils. The adult weevils should be col-
lected and counted from all plants in the sample
area. The area sampled using this technique is 1/200
acre (eight samples of 8 feet 11/2 inches each per
field). Multiply the number of weevils found in each
field by 200 to obtain the estimated weevil population
per acre. A sample of the weevils collected should be
dissected under a microscope to determine the per-
centage which are in the diapause condition.
In areas where large populations usually occur
scouting should be intensified, perhaps to include
every field. These areas also should be scouted first.
Trap catch information can be used to help identify
other areas in which infestations are more intense
and scouting efforts should be increased. For a rule
of thumb, at least three to five fields per 1,000 acres
should be scouted.
Blocking Of Acres To Be Treated
Areas should be blocked for spraying when weevil
populations are estimated (by field scouting) to have
reached 200 to 800 per acre or more and the percent-
age of diapausing weevils reaches 25 percent or
more.
Contracting For Materials
and Services
Aerial Application
Advertising for aerial application services should
begin in September. The description of the job
should include the estimated number of acres to be
treated and the expected dates of treatment. The ad-
vertisement also should inform applicators that they
must be equipped to apply 12 to 16 ounces of ULV
malathion per acre and that flaggers in radio contact
with the pilots are required. Finally, aerial ap-
plicators should be informed that they will be apply-
ing the chemical from a few feet higher than a
conventional application (under the direction of the
program directors) and that the swath widths will be
100 feet. The advertisement should require that all
bidders be inspected by the Texas Department of
Agriculture to be sure that their licensing, bonding,
insurance and equipment are in order.
When evaluating bids the committee should con-
sider the amount of time in which each bidder could
accomplish the job. Small planes should be able to
spray 3,500 acres per day and large planes should be
able to spray 6,000 acres per day. Spraying of the
acreage in the program should be completed in 7
days to ensure that treatments are applied at the
proper time. Keep in mind that weather often causes
delays. The committee should reserve the right to
refuse any and all bids.
The blocked acres should be
sprayed the first time when
weevils first begin to enter
diapause (early October for West
,-:;;::---~.
Texas). Field scouting should continue while spraying
is in progress so that newly infested fields can be
blocked and treated with second, third and fourth ap-
plications. Subsequent applications should be made
only to unharvested cotton within the original block-
ed acreage and to newly infe~ted, unharvested cot-
ton. The second treatment should be applied 10 to
14 days after the first treatment. Committee mem-
bers (district directors) should poll each farmer in
their districts just prior to the second application to
determine the acreage within the blocked portion of
the control zone that has been harvested (and will
not be sprayed). They can then determine the acres
to be sprayed (tank loads required and the payment
to the applicator).
Second and third applications may not be neces-
sary in those years when an early freeze or drought
terminates the crop, allowing an early harvest or caus-
ing a rapid decline in late October boll weevil ac-
tivity. However, plans should be made for second and
third applications which will be needed in most years.
A third application should go out 10 to 14 days after
the second treatment. Occassionally, a fourth ap-
plication is needed on a few acres.
Chemical and Services
In early September when
advertising for the aerial ap-
'--IIiiiiiiiiiiii; ~=----- ~~
plication is done, bids for insecticide purchase also
should be solicited. ULV malathion should be
specified because problems relating to human health,
livestock and wildlife have been associated with other
insecticides. The amount of insecticide required
should be calculated based on a use rate of 1 pint of
ULV malathion per acre per application. Liability in-
surance for the diapause control program should be
considered. The committee should arrange to hire
an accountant to prepare the books for audit and en-
sure proper disposition of funds.
Evaluation
Since there are many factors that impinge on the
success of a boll weevil diapause control program
(e.g., winter weather, overwintering habitat, nearby
untreated cotton, crop earliness, etc.), a meaningful
evaluation can be made only after several years in the
program. Diapause control programs are long term
programs, and it is essential that growers understand
that when they embark on this program they should
be committed to it for at least 3 years.
Evaluations are essential each year, so that at the
end of 3 or 4 years a decision can be made about
whether or not the program is successful and should
be continued.
A pre-program survey should be conducted to
determine how many in-season insecticide treatments
per acre were used to control boll weevil and
other insects during the preceeding 2 to 3 years. Year-
ly surveys of the diapause control program should be
conducted to obtain similar information critical to
the evaluation of the program. A reduction of in-
season insecticide applications for boll weevil and
secondary pests over a 3-year period is a good in-
dicator of the program's success. Records of boll
weevils captured in pheromone traps during the
spring and fall are also useful in the program's evalua-
tion. An assessment of the program's impact on the
overwintering boll weevil population can be obtained
after the first year by sampling overwintering habitat.
Samples from overwintering habitat in the control
zone, when compared with those collected from
similar habitat near cotton fields outside the control
zone, can provide an early indication of effectiveness.
However, sampling to determine weevil numbers in
winter habitat does require a large commitment of
time.
The fall boll weevil diapause control program is a
proven method of managing weevil populations.
However, the proper organization and cooperation
of virtually 100 percent of the producers within the
control zone are essential for the success of the pro-
gram.
Acknowledgements
The authors gratefully acknowledge the assistance of Mr. Roger Haldenby, Plains
Cotton Growers; Dr. Don Rummel, Texas Agricultural Experiment Station
(TAES); Dr. JeffSlosser, TAES; Mr. Emory Boring, Texas Agricultural Extension
Service (TAEX); Dr. Thomas Fuchs, TAEX; Dr. James Leser, TAEX; Dr. Ray
Frisbie, TAEX; and Dr. Philip Hamman, TAEX.
Educational programs conducted by the Texas Agricultural Extension Setvice serve people of all ages regardless of socioeconomic level, race,
color, sex, religion, handicap or national origin.
Issued in furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of Congress of May 8, 1914, as amended, and
June 30, 1914, in cooperation with the United States Department of Agriculture. Zcrle L. Carpenter, Director, Texas Agricultural Extension
Service, The Texas A&M University System.
3M- 7-90, New AGR 2


English

https://figshare.com/articles/Additional_file_12_Figure_S8_of_Population_Dynamics_Among_six_Major_Groups_of_the_Oryza_rufipogon_Species_Complex_Wild_Relative_of_Cultivated_Asian_Rice/4351982