Insect Pest Shifts Following the Adoption of bollgard

1
Insect Management by North Carolina Leafy Green
Growers
Stephen J. Toth, Jr. and Kenneth A. Sorensen,
Department of EntomologyNorth Carolina State
University, Raleigh, North Carolina 27695-7613
USA
Insecticide Applications. A total of 49
respondents (78) reported the use of insecticide
to manage insects on their leafy greens in 1999.
Insects for which insecticides were used included
cabbage loopers (77 of respondents using
insecticide), diamondback moths (55), imported
cabbage-worms (45), aphids (45) and harlequin
bugs (Figure 1) (35) on collards, diamondback
moths (18), aphids (16), cabbage loopers (14),
imported cabbageworms (14) and flea beetles
(14) on kale, aphids (27), diamondback moths
(22), flea beetles (18) and cabbage loopers
(16) on mustard greens, and aphids (29),
diamondback moths (24), imported cabbage-worms
(18) and flea beetles (18) on turnip greens.
Insecticides applied to manage insects on
collards, kale, mustard greens and turnips greens
are listed in Tables 1-4. Integrated Pest
Management (IPM). Fifty-six percent of the
respondents claimed that they practiced
integrated pest management in growing leafy
greens, while 85 consider-ed IPM to be a good
pest management practice. Eighty-six percent of
respondents reported that they walked their
fields to scout for insects and their damage
however, only 10 kept records of scouting
information. Approximately 7 of respondents
used parasites and/or predators to management
insect pests of leafy greens. Three percent of
respondents used seed baits in soil or light
traps to monitor insect pests, while only 1 used
sex pheromone traps (Figure 2). Asked who scouted
their leafy greens for weeds, insects and
diseases, 98 of respondents reported that they
or a family member scouted their crop in 1999.
Nearly 7 claimed that an employee scouted their
crop, while professional scouts or consultants
provided this service for less than 2 of the
respondents. Survey respondents were asked
to report their sources of information on leafy
green pest management. The North Carolina
Cooperative Extension Service was a source of
information for 60 of respondents, followed by
other growers (39 of respondents) and pesticide
dealers (32). Eighty-one percent of respondents
indicated that they would like to receive
information on IPM. The methods by which they
preferred to receive IPM information were printed
materials (79 of respondents), direct contact
from county Extension agents, consultants, etc.
(35), scouting schools, on-farm demonstrations,
etc. (9) and computers (electronic mail,
Internet, etc.) (7).
ABSTRACT A mail survey of leafy green (i.e.,
collards, kale, turnip greens and mustard greens)
growers in North Carolina was conducted by the
North Carolina Cooperative Extension Service in
April 2000 to determine the pest management
practices used by leafy green growers during
1999. Results of the survey include data on the
insect management practices of leafy green
growers as well as information on the uses and
attitudes of leafy green growers toward
integrated pest management.
Figure 2. County Extension agent checking
diamondback moth sex pheromone trap. Photograph
by Ken Sorensen.
Figure 1. Harlequin bugs on collards.
Photograph by Ken Sorensen.
SURVEY METHOD Data on pesticide use,
integrated pest management and leafy green
production were collected by mail from leafy
green growers identified in the following 22
counties in North Carolina Brunswick, Cherokee,
Columbus, Cumber-land, Duplin, Edgecombe, Greene,
Halifax, Iredell, Johnston, Lee, Lenoir,
Montgomery, Onslow, Pitt, Rich-mond, Robeson,
Sampson, Union, Wake, Wayne, and Wilson. Mailing
lists of growers were obtained from county
Extension centers. On April 11, 2000, 430 leafy
green growers in the participating counties were
sent an initial correspondence, including a cover
letter, survey question-naire and pre-stamped
envelope in which to return the questionnaire
(Christenson 1975, Dillman 1978, Salant and
Dillman 1994), by mail. After one week, a
follow-up post-card was sent to each grower as a
reminder to complete and return the
questionnaire. After three weeks, another
correspondence, containing a cover letter,
questionnaire and pre-stamped envelope, was sent
to all non-responding growers. Questionnaires
were coded with identification numbers in order
to identify non-respondents. Information
collected from the survey questionnaires was
compiled and analysis in the Department of
Entomology at North Carolina State University.
Table 1. Insecticides applied to collards by
North Carolina growers to manage
insects. Insecticide Acres Treated Acres
Treated1 Ambush 444.40 30.05
Asana XL 547.00 36.99 Diazinon
453.25 30.65 Dimethoate
300.00 20.29 Dipel (B.t.) 1,249.20
84.48 Lannate 282.00
19.07 Lorsban 100.00 6.76
Malathion 432.75 29.26 Mattch
(B.t.) 200.00 13.52 Phaser
740.50 50.08 Provado 450.00
30.43 Sevin 293.85 19.87
Spintor 1,307.40 88.41 Thiodan
850.00 57.48 Xentari (B.t.)
1,054.25 71.29 1 Acres of collards
planted 1,478.775
Table 2. Insecticides applied to kale by North
Carolina growers to manage insects.
Insecticide Acres Treated Acres Treated1
Ambush 250.00 55.66 Asana XL
155.00 34.51 Diazinon 250.75
55.82 Dimethoate 150.00
33.39 Dipel (B.t.) 350.50 78.03
Lannate 282.00 19.07 Malathion
75.75 16.86 Mattch (B.t.)
180.00 40.07 Phaser 155.00
34.51 Provado 110.00 24.49
Spintor 170.00 37.85 Thiodan
75.00 16.70 Xentari (B.t.)
350.00 77.92 1 Acres of kale planted
449.175
Table 3. Insecticides applied to mustard
greens by North Carolina growers to manage
insects. Insecticide Acres Treated Acres
Treated1 Dimethoate 200.00 25.07
Dipel (B.t.) 703.55 88.19
Malathion 102.50 12.85 Phaser
200.33 25.11 Provado 73.00
9.15 Sevin 50.83
6.37 Spintor 700.00 87.75
Xentari (B.t.) 700.00 87.75 1
Acres of mustard greens planted 797.75
Table 4. Insecticides applied to turnip greens
by North Carolina growers to manage
insects. Insecticide Acres Treated Acres
Treated1 Ambush 151.25 19.78
Diazinon 150.25 19.65
Dimethoate 300.00 39.23 Dipel
(B.t.) 654.08 85.54 Malathion
102.23 13.37 Mattch (B.t.)
100.00 13.08 1 Acres of turnip
greens planted 764.65
RESULTS AND DISCUSSION Leafy Green Production.
Of the 430 individuals surveyed, 222 (52)
responded. However, only 75 respondents planted
leafy greens in 1999, and only 64 were commercial
growers. Data were collected from questionnaires
returned by the 64 commercial growers responding
to the survey. These respondents, representing
every county surveyed except for Cherokee County,
planted 1,478.775 acres of collards, 449.175
acres of kale, 797.75 acres of mustard greens and
764.65 acres of turnip greens. They harvested
908.93 acres of collards, 197.70 acres of kale,
376.36 acres of mustard greens and 360.86 acres
of turnip greens. The 1999 growing season was
marked by extreme weather conditions in North
Carolina, significantly reducing leafy green
production. Approximately 78 of the respondents
reported that their yields were effected by
extreme weather, including hurricanes, floods,
drought, heat and wind).
LITERATURE CITED Christenson, J. A. 1975. A
procedure for conducting mail surveys with the
general public. J. Community Develop-ment
Society 6(1) 135-146. Dillman, D. A. 1978.
Mail and Telephone Surveys The Total Design
Method. John Wiley and Sons, New York. 325
pp. Salant, P. and D. A. Dillman. 1991. How to
Conduct Your Own Survey. John Wiley and Sons,
New York. 232 pp.
The use of trade names of pesticides does not
imply endorsement of these products by the North
Carolina Cooperative Extension Service nor
discrimination against similar products. This
project was supported by a grant from the
Southern Region Pesticide Impact Assessment
Program, University of Florida.