• TABLE OF CONTENTS
HIDE
 Front Cover
 Title Page
 Acknowledgement
 Table of Contents
 Abstract
 Introduction
 Summary of general questions asked...
 Specific questions addressed to...
 Specific questions addressed to...
 Specific questions addressed to...
 Specific questions addressed to...
 Summary remarks
 Literature cited
 Questionnaire
 Back Cover














Group Title: Bulletin - Agricultural Experiment Station. University of Florida ; 875
Title: The Impact of integrated pest management on selected vegetable crops in Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00086509/00001
 Material Information
Title: The Impact of integrated pest management on selected vegetable crops in Florida
Series Title: Bulletin
Physical Description: vi, 67 p. : ill. ; 23 cm.
Language: English
Creator: Pohronezny, Ken, 1946-
Publisher: Agricultural Experiment Station, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1989
 Subjects
Subject: Plant parasites -- Control   ( lcsh )
Pesticides -- Application   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 55-56).
Statement of Responsibility: Ken Pohronezny ... et al..
General Note: "September 1989"--Cover.
Funding: Bulletin (University of Florida. Agricultural Experiment Station) ;
 Record Information
Bibliographic ID: UF00086509
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 21348354

Table of Contents
    Front Cover
        Front Cover
    Title Page
        Page i
    Acknowledgement
        Page ii
    Table of Contents
        Page iii
        Page iv
    Abstract
        Page v
        Page vi
    Introduction
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
    Summary of general questions asked of all growers surveyed
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
    Specific questions addressed to tomato growers
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
    Specific questions addressed to snap bean growers
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
    Specific questions addressed to strawberry growers
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
    Specific questions addressed to pepper growers
        Page 47
        Page 48
        Page 49
        Page 50
        Page 51
        Page 52
    Summary remarks
        Page 53
        Page 54
    Literature cited
        Page 55
        Page 56
    Questionnaire
        Page 57
        Page 58
        Page 59
        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
        Page 65
        Page 66
        Page 67
    Back Cover
        Back Cover
Full Text


September 1989


The Impact of Integrated Pest Management
on
Selected Vegetable Crops in Florida

Ken Pohronezny, Editor


Library


MAR 29 ;t:

Unveisity of Florida
Agricultural Experiment Sta T'n -'' '-
Institute of Food and Agricultural Sciences
University of Florida, Gainesville
J. M. Davidson, Dean for Research


Bulletin 875













The Impact of

Integrated Pest Management on
Selected Vegetable Crops in Florida


Ken Pohronezny, David J. Schuster, Richard Tyson,
Phyliss Gilreath, Richard Mitchell, Reginald Brown,
Van H. Waddill, Robert McSorley, James Price,
William Summerhill, Wilbur Dankers, and Richard Sprenkel



Authors
All authors are (or formerly were) faculty members of the University of
Florida, Institute of Food and Agricultural Sciences, at various locations:

Ken Pohronezny, formerly at the Tropical Research and Education Center,
Homestead, now at the Everglades Research and Education Center, Belle
Glade
David J. Schuster, Gulf Coast Research and Education Center, Bradenton
Richard Tyson, formerly with the Dade County Cooperative Extension
Service, Homestead, now with Collier Growers, Immokalee
Reginald Brown, Collier County Cooperative Extension Service, Naples
Phyliss Gilreath, Manatee County Cooperative Extension Service, Palmetto
Richard Mitchell, Hillsborough County Cooperative Extension Service,
Seffner
Van H. Waddill, formerly at the Tropical Research and Education Center,
Homestead, now at the Everglades Research and Education Center, Belle
Glade
Robert McSorley, formerly at the Tropical Research and Education Center,
Homestead, now in the Department of Entomology and Nematology,
University of Florida, Gainesville
James Price, Gulf Coast Research and Education Center, Bradenton
William Summerhill, IFAS Program Evaluation, Gainesville
Wilbur Dankers, Tropical Research and Education Center, Homestead
Richard Sprenkel, North Florida Research and Education Center, Quincy





















Cover
The cover illustration shows Joyce Francis using a beat cloth to count
pests in a snap bean field in Homestead, Florida. Mrs. Francis was an IPM
scout who worked for IFAS for eight years before her death in 1985.





Acknowledgements
We thank Mary Jackson for preparation of figures, Bobbi M. Drawdy for
manuscript preparation, Mary Cilley and Sally Knox for editorial assistance,
and David Miller for the cover design and final rendering of figures.












Contents

Page

Abstract .......................................... v

Chapter 1: Introduction .............................. 1

Chapter 2: Summary of general questions asked
of all growers surveyed ............................. 7

Chapter 3: Specific questions addressed to
tomato growers .................................. 23

Chapter 4: Specific questions addressed to
snap bean growers ................................ 29

Chapter 5: Specific questions addressed to
strawberry growers ................................ 39

Chapter 6: Specific questions addressed to
pepper growers .................................. 47

Chapter 7: Summary remarks ......................... 53

Literature Cited .................................... 55

Appendix: Questionnaire ............................57













Abstract
A study on the impact of educational programs in integrated pest
management (IPM) on vegetables was made by the Florida Cooperative
Extension Service from 1984 to 1986. Data collected consisted of
answers to a questionnaire on IPM attitudes and practices of IPM.
The majority of the data were collected during interviews of growers
by county agents. Participating counties were Dade, Collier, Manatee,
and Hillsborough. Four crops representative of the range of involve-
ment by the Cooperative Extension Service in vegetable IPM were
included: tomato, snap bean, strawberry, and bell pepper.
Based on the data in this study, we conclude that extension IPM
programs have a substantial positive impact on production of these
crops. Disease and insect management accounts for most of the
behavioral changes and economic impacts. Nematode and weed control
practices have been less influenced by IPM programs. Percentages
of acreage scouted were: tomato, 47%; snap bean, 34%; strawberry,
14%; and bell pepper, 36%. Some type of commercial scouting (that
done by personnel trained by the Florida Cooperative Extension
Service) was used by 24 of the 81 growers interviewed. Sixty-two
percent of the growers reported that net returns (savings in pesticide
costs minus scouting fees) were increased through IPM. Savings aver-
aged $95.00/acre across the four commodities. Tomato farmers reported
savings of $121.00 an acre.
Most of the economic benefits relate directly to fewer applications
of pesticides. Overall, 83% of the growers reported that use of insecti-
cides has decreased as a result of involvement in IPM. On the average,
the amount of insecticide and miticide (lb a.i./acre) sprayed has
decreased 21.1%. Decreases ranged from 10% for snap bean to 50%
for bell pepper. Most growers reported that fungicide use remained
the same after initiation of IPM programs, but about 29% reported
a reduction of fungicides, averaging about 9% (lb a.i./acre). Human
health and environmental benefits may accrue from the lower amounts
of pesticides used.
Projected to the total tomato acreage in the four county areas,
savings from IPM scouting are about$1.3 million annually. Projections
for snap beans are $43,430 annually. However, growers did not list
cost savings as the major benefit realized in IPM programs. Rather,
early and accurate identification of pests was viewed as the major
incentive for hiring scouts.
Highlights of some of the responses to specific commodity questions
are given. Most growers were aware of the importance of insect








predators and parasites. About 57% of the growers of both tomato
and snap beans said that they considered the status of leafminer
parasites before making the decision whether or not to apply insec-
ticides. Among the tomato growers, 39% were aware of the Florida
Agricultural Information Retrieval System (FAIRS); 82% indicated a
desire to have access to FAIRS. Hypochlorite treatment of seed was
common among tomato growers (43%) but was not used by any of
the pepper growers interviewed. Broad-spectrum fumigants (primarily
those containing methyl bromide) were used on most of the acreage
for all four crops. Preplant sampling to assess nematode populations
was uncommon. Use of streptomycin to control bacterial spot also
was widespread among tomato growers (47%) but not among pepper
growers (7.5%). Many bean growers were still spraying fungicides
specifically to control white mold (Sclerotinia sclerotiorum) before the
disease is likely to occur. They also continue to space plants very
closely within the row, despite the tendency of this practice to aggravate
several pest problems. There has been an increase in the percentage
of growers who spray beans with fungicides in accordance with
Canadian laws and Florida Cooperative Extension Service recommenda-
tions. Little consideration is being given to the location of strawberry
fields in the integrated management of pests. Although great differ-
ferences in susceptibility of strawberry fruit to anthracnose exist,
cultivars are selected primarily on the basis of horticultural characteris-
tics and market appeal. Strawberry growers are very much interested
in the potential for biological control of two-spotted spider mites. They
would use predatory mites if they were commercially available.
Horticultural traits (including shape and size of fruit) were rated more
highly than pest resistance in selection of pepper cultivars.
The pest problems identified by growers were, for the most part,
also perceived as important to IFAS. Some of the problems listed
most frequently were:
tomato bacterial spot, leafminers, late blight
snap bean leafminers, white mold, rust
strawberry mites, anthracnose
bell pepper bacterial spot, pepper weevil, caterpillars
Across all crops, root-knot and sting nematodes were listed as the
most serious nematode pests. Black nightshade, nutsedges, pigweeds,
and Parthenium were viewed as the most noxious weed problems.
At present, extension programs in IFAS are targeting many of the
areas of concern to growers. Emphasis in the future may be con-
centrated on increasing the frequency of grower acceptance of program
tenets.








Chapter 1

Introduction




Brief history of integrated pest management
on vegetables in Florida
Integrated pest management (IPM) has become a widely known
and commonly used component of modern-day systems of agricultural
production. Indeed, as an indication of our confidence in the pervasive-
ness of the IPM concept among agriculturists, we will forego the usual
introductory definitions. The reader is referred to Getz and Guitierrez
(1), Harris (3), Pohronezny and Waddill (12), and Stern et al. (18) for
definitions of IPM and summaries of its scope and philosophy.
By the mid 1970s substantial effort had been made by IFAS in
both extension and research to develop IPM programs. Specific
commodities studied included soybeans, citrus (19), and celery (2).
During the 1976-77 winter vegetable season, Florida's $200 million
fresh-market tomato industry was threatened by a severe outbreak
of leafminers (Liriomyza spp). As many as 34 insecticide applications
were made to a single crop in a vain effort to control these pests (13).
Failure of control primarily was due to resistance to the then-available
pesticides and to heavy mortality of parasites of leafminers by
broad-spectrum insecticides.
Diseases, especially bacterial spot and late blight, continued to
cause heavy losses in many fields (13).
Several growers were interested in innovative approaches to the
solution of this dilemma. A pilot IPM program was subsequently
established in Dade County by the Florida Cooperative Extension
Service in the winter of 1976-77 (14) and was expanded to Manatee
and Hillsborough Counties in 1978 (15).
After approximately two seasons of public support, growers assumed
the full costs for scouting. Most of the vegetable acreage now being
scouted is handled by employees of private pest management com-
panies. Contractual arrangements between scouting firms and grower
clients are agreed upon and monies are provided periodically during
the crop cycle or in a lump sum, usually at planting. A few large
farming operations have even hired their own personnel with primary
responsibilities for field scouting. It should be noted that at least one
pest management firm was operational before the first pilot program
sponsored by IFAS was in place.








Not surprisingly, interest in IPM for other vegetable crops soon
developed. Indeed, ideas for other crops came from scouts, growers,
and IFAS extension and research workers. Considerable effort by
IFAS personnel was made in the development of a program for snap
beans, and some support was established for strawberries. All
scouting companies initiated their own trial-and-error efforts in other
crops, including sweet corn, cole crops, and pepper.
Some of the sampling techniques and action thresholds used on
these crops are unknown to persons outside these firms and are
viewed by these entrepreneurs as "trade secrets." At least some of
these protocols have not been subjected to scientific scrutiny; their
applicability has been tested only in the marketplace.
As the private sector took over the routine business of scouting,
extension programs concentrated on educational support for growers,
scouts, and consultants. Researchers continued to fill data gaps
identified by extension personnel.
With such a large programmatic commitment by IFAS, an
evaluation of the impact of IPM on grower attitudes and practices was
needed. An IPM component for vegetables was included in 1984 as
a part of the major state plan to examine the impact of IPM educational
programs on IPM production practices for a number of crops.
Originally, tomato was the only vegetable commodity to be included
in the study; however, the design committee expanded the study to
include snap bean, strawberry, and bell pepper.

Vegetable commodities included in impact study
Tomato has had the longest history of active educational programs
by IFAS and the greatest effort in public-supported demonstration
plots in farmers' fields. Additionally, tomato constitutes, by far, the
largest source of revenue for private IPM companies specializing in
vegetable crops. Any evaluation of the impact of Florida Cooperative
Extension Service programs would naturally include this crop.
Snap bean was the second vegetable commodity to receive concen-
trated attention by IFAS. A sound research base already existed for
sampling and action thresholds for several key insect pests of the
crop. In addition, a very large data base adaptable in several aspects
to snap bean was available in the soybean literature. Snap bean is
also an excellent example of a crop for which IPM principles other
than scouting are readily adaptable to extension education programs.
These include pest control through plant spacing arrangements, variety
selection, and use of pesticides compatible with Canadian residue
tolerances.
Strawberry is a crop in transition as far as IPM is concerned.
Plants traditionally have been sprayed quite heavily with pesticides.








Some of these applications, particularly miticides, are probably not
warranted because pest densities are below injury levels. Several IPM
firms have begun scouting strawberries with little, if any, direct
assistance and training from IFAS. They have developed their own
sampling schemes and action thresholds (primarily for mites), based
on available California literature. The driving force to establish IPM
protocols for strawberry has been primarily from outside the University
system. This contrasts sharply with the tomato and snap bean areas
where formal IFAS programs preceded substantial private sector
activity.
Bell pepper was chosen, because it is a crop for which limited IPM
information is available. Many IFAS workers have expressed concern
about the application of traditional IPM practices (e.g., "scout-and-
spray" for insects) in bell pepper. Pepper weevil and aphid-transmitted
viruses are recurrent and severe problems with low damage thresholds
(22). Much less is known about pest management practices in pepper
than in tomato and snap bean. Therefore, the impact study was viewed
as an opportunity to explore the current status of pest management
knowledge and practice in the pepper industry.
Despite information gaps, there is substantial interest in IPM for
peppers among the grower clientele. Some pepper acreage is already
scouted by private companies. Little, if any, information is available
to IFAS on the scouting procedures in use. The impact study was
a means of establishing baseline data on the pepper industry and IPM
and to set educational goals and strategies for the crop.

Design of the survey document
Information for the impact study was gathered through a survey
of growers in four southern Florida counties: Dade, Collier, Manatee,
and Hillsborough. Every effort was made to contact all growers in
each commodity. However, since it was not possible to reach all
growers, special effort was made to assure that those representing
the largest acreage were interviewed. A survey questionnaire was
designed in 1984 (Appendix). The questions in the document reflected
several major objectives of the study:
a) to collect demographic-like data such as acres grown, acres
scouted, growers interviewed, etc.;
b) to determine the status of grower practices with respect to
objectives of ongoing plans of IFAS Cooperative Extension in
the area of pest management;
c) to determine levels of grower understanding of pest biology
(pest, beneficial organism, crop interaction) and of IPM
principles;








d) to record the most important pest management problems as
perceived by growers.
Because of the very specific, often fairly technical items on the
questionnaire, county agents specializing in vegetable crops in parti-
cipating counties contacted growers directly when possible. Some
growers were surveyed by mail when efforts to contact them directly
were not successful. Every attempt was made to survey all growers
of each commodity in each county. However, this was not possible.
Therefore, the growers with the largest acreage were targeted in this
study. Therefore, 80% or more of the acreage was represented in most
cases. Data were collected from the winter of 1984 to the summer
of 1986. The percentage of growers in the survey who were inter-
viewed in person are as follows: Hillsborough, 90%; Manatee, 90%;
Collier, 80%; Dade, 95%.
The survey document was divided into five parts. The first section
contained questions asked of all growers contacted regardless of
commodity grown. Then growers of each of the four commodities
were asked a series of specific questions for that commodity.
Interpretation of these data is somewhat limited, because 100%
of the growers and acreage was not included in the survey. Those
growers with a history of active cooperation with the Florida Coopera-
tive Extension Service were the most accessible and most willing to
cooperate in our study. These are the same growers who were most
interested when the pilot IPM programs were initiated. Therefore,
some data may be biased in favor of the objectives of the IPM
programs.
On the other hand, the timing of this study was a source of bias
against the impact of IFAS IPM programs on vegetables. Many of
the most dramatic behavioral changes among tomato growers were
recorded by 1980 (13). Hence, the "baseline" data collected from
1984 to 1986 no doubt underestimate some positive impacts of
educational programs in place since the late 1970s.
Ambiguity and misunderstanding were minimal problems on
individual survey sheets, especially when one-on-one interviews of
growers were made by county agents. The most troublesome spot
seemed to be in the directional statement immediately after Question
No. 2, Section I (Appendix): "IF NONE OF YOUR ACREAGE IS
SCOUTED, SKIP TO NO. 9." For the purpose of the survey, "scout-
ing" was defined (at least in the minds of the survey designers) as
formal sampling, carried out by personnel specifically trained to use
monitoring schemes recommended by the Florida Cooperative Extension
Service. Growers not using "commercial scouts" would presumably
skip from Question 2 to Question 9 of Section I (Appendix). However,








most growers answered all intervening questions. This occurred
because many growers felt that they were monitoring their fields even
though commercial scouting services were not used. Furthermore,
these monitoring activities (hereafter referred to as "minimal monitor-
ing") were perceived as important components of their pest manage-
ment efforts. In many aspects, this study then is a comparison between
acreage scouted in a formal, professional way and that monitored in
a less structured fashion.

Data management
The sheer volume of data received from agents, coupled with the
specificity of the individual questions necessitated writing a custom-
tailored computer program to handle the data. Data were recorded
and summarized on a real-time basis. The program was written in
AppleSoft BASIC. It is interactive enough to be used readily by those
familiar with BASIC and the operation of the Apple systems. It can
be run on Apple II, Apple He, and Apple Il (operated in Emulator
mode). A complete copy of the BASIC program is available upon
request from the senior author.
In order to apply rigorous statistical analyses to the data all growers
in each commodity would have had to be interviewed. It was simply
impossible to reach every grower. Therefore, statistical treatment of
the data could not be done. However, we made a concerted effort to
visit the majority of the larger farms in each county. Therefore, a
large portion of the acreage planted was included in the data. Options
in the program allowed for up-to-the-minute summary of data by
county, commodity, or combinations of county and commodity. Geo-
graphical breakdown of the data is not often shown in this paper.
However, those readers interested in more specific information, and
who have compatible computer equipment, may request copies of the
program on 5.25-inch diskettes. Address inquiries to:
Mr. Hank Dankers
IFAS, University of Florida
Tropical Research and Education Center
18905 SW 280th Street
Homestead, FL 33031
(305) 245-3566

Data summaries
The data in this report should be of interest to county agents,
other IFAS faculty and administrators, grower groups, scouts and
consultants, and the general public. The data summaries will follow,
for the most part, the sequence of questions in the survey document







(Appendix). One chapter each is devoted to the general questions and
to the four vegetable commodities. When possible, data are expressed
in tabular or graphic form.
Information in this report should provide a basis for evaluation
of the effectiveness of present extension programs as well as feedback
to IFAS extension and research personnel on grower-perceived
problems and needs. It is planned that another survey be conducted
in approximately five years to help determine progress in ongoing
extension programs.








Chapter 2

Summary of General Questions
Asked of All Growers Surveyed



Grower involvement in IPM programs
A total of 81 growers responded to the survey (Table 1). Numbers
of respondents were: tomato, 47; snap bean, 12; pepper, 10; and
strawberry, 12. A total of 37,763 acres were represented in the survey.
Acreage represented were: tomato, 25,995; snap bean, 8630; pepper,
2550; and strawberry, 578 (Table 1).
Comparisons were made between the acreage represented in the
survey and the total planted acres by county as summarized by the
Crop and Livestock Reporting Service. Percentage representation
varied considerably (Table 1). Some of the more comprehensive surveys
were made for pepper and tomato in Manatee County and for tomatoes
in Dade County. Across the board, about 56% of all the acreage
planted in the four commodities was included in this study. Data for
tomatoes are likely to be most reliable since nearly 70% of the planted
acres was included.
Commercial scouting is defined as that done by persons employed
by a firm specifically incorporated to perform such services or by
persons hired on grower payrolls with primary responsibilities for field
scouting. Based on survey data, scouting has a substantial impact
on the southern Florida vegetable industry. About 40% of the tomato
growers surveyed used commercial scouting (Table 2). In Collier
County, over 80% of the tomato growers availed themselves of scout-
ing services. Among growers of other commodities, preferences for
commercial scouting were: snap beans, 33%; peppers, 20%; and
strawberries, 17%.
Participation in formal IPM programs has grown from four tomato
farmers in the pilot program in Dade County in 1976-77 (13) to 24
growers in four commodities in four counties (Table 3). The survey
found active commercial scouting on 16,305 acres of vegetables, up from
the modest 365 acres scouted in the first season of the pilot program
in Dade County.
Sixty-three of the 81 growers reported that some type of periodic
field inspections for pests were made (minimal scouting, Table 3).
Minimal scouting was common among tomato and snap bean growers








Table 1. Number of growers and acreage represented in the survey of the impact
of the IPM program on vegetables sponsored by IFAS upon usage
of IPM by growers of four vegetable crops.
Percentage of
No. of Total planted acreage
growers Acreage planted (1984-85)
reporting represented acreage represented
Commodity Area in survey in survey (1984-85)b in survey

Tomatoes Dade 9 8,620 11,200 77.0
Collier 8 6,535 8,800 74.3
Manatee 22 8,920 11,100 88.5
Hillsborough 8 1,920 6,450 29.8
Survey total 47 25,995 37,550 69.2

Snap beans Dade 10 7,890 18,800 42.0
Hillsborough 2 740 1,600 46.3
Survey total 12 8,630 20,400 42.3

Peppers Collier 2 920 2,800 32.9
Manatee 4 1,020 1,020 100.0
Hillsborough 4 610 1,600 38.1
Survey total 10 2,550 5,420 47.0

Strawberries Manatee 2 50 150 33.3
Hillsborough 10 528 4,350 12.1
Survey total 12 578 4,500 12.8

Four-crop Dade 19 16,510 30,000 55.0
total Collier 10 7,455 11,600 64.3
Manatee 28 9,990 12,270 81.4
Hillsborough 24 3,808 14,000 27.2
Survey total 81 37,763 67,870 55.6
a. Counties reporting only those commodities of locally important economic interest.
b. Data from Crop and Lvestock Reporting Service, Orlando.

(89% and 92%, respectively). It was lower for pepper and strawberry
growers (50% and 33%, respectively). Few growers skipped from
Question 2 to Question 9 of the general question section of the survey
document (Appendix). Perhaps growers have a less restrictive view
of IPM. Some in extension tend to place such emphasis on extension-
recommended scouting that "scouting" (as we define commercial scout-








ing) becomes synonymous with IPM. Field inspections that consti-
tute minimal scouting are not as systematic as extension-recommened
plans and are not based on research results. However, data in this
report show that positive results from minimal scouting have occurred.
It is evident that commercial scouts, chemical company fieldmen,
and growers may all inspect the same fields (Table 2). This "redun-
dancy" in field monitoring may reflect grower concerns about the high
cash value of the crops. Growers view the multiple inspections of fields
as a worthwhile type of crop insurance.

Table 2. Profile of how field scouting is accomplished in fields of growers
interviewed during IPM impact survey.
Percentage of growers surveyed
using field monitoring information from:
Commercial "Payroll"b Grower Chem. co.
Commodity Area scouting firms scouts self-scouting fieldmen

Tomatoes Dade 11.1 22.2 88.9 11.1
Collier 37.5 50.0 25.0 0.0
Manatee 13.6 0.0 59.1 40.9
Hillsborough 62.5 12.5 62.5 25.0
Survey total 25.5 14.9 59.6 25.5

Snap beans Dade 20.0 10.0 80.0 30.0
Hillsborough 0.0 50.0 0.0 0.0
Survey total 16.7 16.7 66.7 25.0

Peppers Collier 50.0 50.0 0.0 0.0
Manatee 0.0 0.0 50.0 50.0
Hillsborough 0.0 0.0 25.0 0.0
Survey total 10.0 10.0 30.0 20.0

Strawberries Manatee 50.0 0.0 50.0 0.0
Hillsborough 10.0 0.0 20.0 10.0
Survey total 16.7 0.0 25.0 8.3

a. Data in rows may add to more than 100%, since a substantial number of growers use
more than one type of monitoring (e.g., commercial firm and chemical company
fieldmen) on the same fields.
b. Personnel on company payroll hired with primary job responsibility for scouting as
recommended by the Florida Cooperative Extension Service.








Table 3. Impact of commercial scouting verses minimal monitoring on acreage
represented in the survey of the impact of IPM upon grower practices.

Farms using commercial Farms using at least
scouts minimal monitoring
Commodity Area No. growers Acreage No. growers Acreage

Tomatoes Dade 2 3,700 9 7,070
Collier 6 5,435 7 5,435
Manatee 3 2,200 19 8,350
Hillsborough 5 1,030 7 1,180
Survey Total 16 12,365 42 22,035

Snap beans Dade 3 2,240 10 6,830
Hillsborough 1 700 1 700

Survey Total 4 2,940 11 7,530

Peppers Collier 2 920 2 920
Manatee 0 0 2 600
Hillsborough 0 0 1 100

Survey Total 2 920 5 1,620

Strawberries Manatee 1 30 2 50
Hillsborough 1 50 3 118

Survey Total 2 80 5 168



Use of IPM information in decision making
by management
Questions 4-8 (Appendix) were designed to ascertain what pest
problems are included in written scouting reports and to what extent
the information is used by farm managers. Most growers, whether
or not they received a written report from a commercial scout,
completed these questions. However, our summaries of these items
are based on responses from growers using commercial scouts.
All growers reported that insect and disease information was included
in the scouting reports that they received (Fig. 1). Nematode and
weed information was included less frequently (29% and 41%, respec-
tively). The information on these reports figured heavily in decisions









100-


t 80o-
o





0 40-


L1. 20- / // A
._ 60-







insects diseases nematodes weeds
Pest categories

Figure 1. Pest categories included in commercial scouting reports as reported
by growers participating in survey of the impact of IPM on grower
practices.

on insect management (Fig. 2). The majority of growers used insect
scouting data at least 2/3 of the time. Data on disease incidence and
severity were used less frequently in management decisions (Fig. 3).
However, substantial numbers of growers do use disease data on
scouting reports to assess efficacy of control programs. In contrast,
information on nematode and weed conditions is not used extensively
(Figs. 4 and 5).
The relative importance of scouting among pest categories is not
surprising. Insects often can be controlled readily on a "scout-and-
spray" basis; i.e., scouts estimate insect pest densities and growers apply
eradicative insecticide sprays at predetermined action thresholds.
Diseases cannot, for the most part, be controlled by scout-and-spray
tactics (5). Protectant fungicides, applied on a calendar basis are
required for adequate disease control. However, scouting still has a
substantial impact on decision-making. This may be a reflection of
the use of scouting to evaluate the efficacy of spray programs for disease
control. It may also relate to the large number of diseases afflicting
Florida vegetables. Adjustments in choice of fungicides are often
warranted in response to specific diagnoses made during scouting visits
and subsequent laboratory tests.









20




0
a,





CD
15-0



0
o




S0% 1-33% 3467% 68-99% 100%


Percentage of times in which scouting reports were used


Figure 2. Percentage of times in which individual growers used scouting report
data in decisions relating to insect control.


0% 1-33% 34-67%
rcentage of times in which scouting


68-99% 100%
reports were used


Figure 3. Percentage of times in which individual growers used scouting report
data in decisions relating to disease control.


20
a>


CL
0)

T


10 -
0

052
a" 5 -
E,

0 o
O -
Pe


NE'










a 20
.,a



V' 15.
o



1 10
0

0 u

i5
= >
z r


0% 1-33% 34-67% 68-99% 100%

Percentage of times in which scouting reports were used

Figure 4. Percentage of times in which individual growers used scouting report
data in decisions relating to nematode control.


0% 1-33% 34-67% 68-99% 100%


Percentage of times


in which scouting reports were used


Figure 5. Percentage of times in which individual growers used scouting report
data in decisions relating to weed control.


F'777~


a 20

.c
0-

I 15
0
a.



I 10
0)
0(a





*o
ir 0
iiC 0


I


I7777


-


-








Nematodes and weeds are controlled mostly by preplant application
of pesticides (e.g., fumigation of plastic-mulched beds or herbicide
treatment of row middles). Obviously, by the time scouts are in the
field, the important decisions concerning nematode and weed control
have already been made. Generalized observations may be made at
the end of a crop cycle which will be useful in planning for subsequent
seasons or double crops.
Growers viewed the early and accurate detection of pests as the
major benefit gained from IPM whether fields were scouted commer-
cially or minimally (Table 4). They did not view savings in pesticide
costs as their main reason for using IPM. Future educational programs
by the Florida Cooperative Extension Service perhaps should emphasize
education of scouts in the detailed diagnoses of plant health problems,
particularly those requiring supplemental attention in a laboratory.
More emphasis should be placed on the advantages of early detection
of pests in educational programs aimed at non-IPM growers.
Growers did not rate reduced environmental pollution highly as a
benefit of IPM programs (Table 4). Contrary to expections, growers
failed to view extension of the lifetime of pesticides very favorably.
For all commodities, the lifetime of pesticides was rated as poorly as
was reduced pollution. This suggests that growers may not fully

Table 4. Rankings of possible benefits of IPM as reported by growers in survey
of the impact of IPM upon grower practices for vegetable commodities.a
Tomato Snapbean Pepper Strawberry Total
Benefit Cb Mc C M C M C M C M

Extended useful life- 3.5 3.4 2.3 3.3 4.0 3.9 4.5 3.7 3.4 3.5
time of pesticides
Increased net returns 2.4 2.3 2.5 2.2 3.0 2.6 1.5 2.0 2.4 2.2
Reduced environ-
mental pollution 3.6 3.8 2.5 3.3 4.0 4.3 4.5 4.6 3.5 3.9
Improved levels of
pest control 1.9 2.2 1.8 1.9 2.0 2.1 3.0 2.6 2.0 2.2
Early detection and
accurate identifi- 1.5 2.2 2.3 1.5 2.0 2.1 1.5 2.2 1.7 2.1
cation of pests

a. Rankings were done from highest to lowest priority (1 = highest priority; 5= lowest
priority). Numbers represent average ranking of all growers surveyed.
b. c = Reports using commercial scouting.
c. M = Reports using minimal scouting.








comprehend the role of excess pesticide usage in the development of
resistant pest strains. Furthermore, growers may be callous to the
relatively rapid buildup of resistance to pesticides noted in the
production of Florida vegetables. In the past, new materials have
often become available to take the place of those no longer effective
due to resistance of the target pest. Growers have been cautioned that
the supply of new, effective pesticides might dwindle. However, with
a few notable exceptions (such as insecticides for leafminer control on
snap beans), new pesticides have become available. Chemical company
interest in tomatoes, in particular, has resulted in a fairly steady supply
of new chemicals to replace ineffective ones. Still, at some point it
is likely that growers will no longer experience the luxury of a steady
stream of new pesticides. Extension programs should be designed to
increase grower awareness of the pesticide-resistance problem and
the contribution of overspraying to its development.

Comparisons of use of pesticides and
of costs of pest management
Sixty-two percent of the growers using commercial scouting reported
that net returns (that is, cost savings of pesticides minus scouting fees)
were increased through participation in IPM programs. Average dollar
savings listed were $95.00/acre. Thirty-eight percent reported that
scouting costs about equalled pesticide cost savings. No growers using
commercial scouts reported that scouting increased their costs of doing
business. Even minimal monitoring had a notable positive impact on
grower costs: 54% of such growers reported a net savings, averaging
$62/acre.
A large percentage (36%) of these growers reported that pesticide
costs remained about the same with monitoring and 9% reported that
minimal monitoring actually represented a net increase in costs.
IPM programs have reduced substantially the amount of insecticides
used. Over 80% and 50% of the growers using commercial and minimal
scouting, respectively, reported that their insecticide use was reduced
as a result of using IPM spray tenets (Fig. 6).
As might be expected, the majority of growers said that fungicide
use remained about the same (Fig. 7). About 31% of the growers using
commercial scouting and about 17% using minimal scouting reported
a fungicide reduction (Fig. 7). Use patterns for insecticides and fungi-
cides for specific commodities are shown in Figures 8-15. Trends for
individual crops were generally comparable to the combined data.
However, a few points are worthy of note. Every snap bean grower
using commercial scouts reduced use of insecticides; however, the
reduction averaged only 10% (Fig. 10). IPM may have less impact
on spray practices for snap beans than for other crops. However,


































*Average percent change in amount of insecticide used.

Figure 6. Impact of commercial and minimal scouting on insecticide usage by
all growers interviewed during IPM impact study.


same increased
Influence of scouting on fungicide use


reduced


100

aD
80



a 60
0
o

.. 40
o
0
a)
L 20


i0,
U- 0


commercial scouting [ ]

_ minimal scouting EA








-9.28*

S-11.4*
+2.0*
F 7 4.0


* Average percent change in amount of fungicide used.

Figure 7. Impact of commercial and minimal scouting on fungicide usage by
all growers interviewed during IPM impact study.


-










100

0" -21.3*
.e 80
o commercial scouting [ ]
-20.3*
minimal scouting -J2
S60
0
%

40
C

2 20


0
same increased reduced
Influence of scouting on usage of insecticides on tomatoes

*Average percent change in amount of insecticide used.
Figure 8. Impact of commercial and minimal scouting on insecticide usage by
tomato growers interviewed during impact study.


100

commercial scouting []
80 minimal scouting [


.60
0

S40
o .13.0*

8 -15.6*
20
20 +17.5*


S0 .
< I I V 1+11.7*

same increased reduced
Influence of scouting on usage of fungicides on tomatoes

* Average percent change in amount of fungicide used.
Figure 9. Impact of commercial and minimal scouting on fungicide usage by
tomato growers interviewed during impact study.

17










100
-10.0*


.2 80 -

commercial scouting []
S60 minimal scouting -8.6*

0

S40 -


20


u- 0
same increased reduced
Influence of scouting on usage of insecticides on snap beans

* Average percent change in amount of insecticide used.
Figure 10. Impact of commercial and minimal scouting on insecticide usage by
snap bean growers interviewed during impact study.


100


Co


80
60
a







0. 20

0)


same increased reduced
Influence of scouting on usage of fungicide on snap beans

Figure 11. Impact of commercial and minimal scouting on fungicide usage by
snap bean growers interviewed during impact study. Few growers
estimated % savings on the survey form; therefore, no savings data
are shown.


commercial scouting [
minimal scouting 3








100 -


80 -


60 -


10


20


same


increased


reduced


Influence of scouting on insecticide usage on peppers

* Average percent change in amount of insecticide used.
Figure 12. Impact of commercial and minimal scouting on insecticide usage by
pepper growers interviewed during impact study.


80 -


60 -


40


20


0


same


increased


reduced


Influence of scouting on fungicide usage on peppers

* Average percent change in amount of fungicide used.
Figure 13. Impact of commercial and minimal scouting on fungicide usage by
pepper growers interviewed during impact study.

19


commercial scouting []
minimal scouting [


-50.0*


-22.7*


commercial scouting []
minimal scouting @

//


/I


I









100
-27.5*
"o
80 -

commercial scouting [ ]
2 60 minimal scouting 3

0
3 4


20
40 -_ / 1-20.0*


CL 20
I T +10.0*

iZ 0
e o / _
same increased reduced
Influence of scouting on insecticide and miticide usage on strawberries

*Average percent change in amount of insecticide and miticide used.
Figure 14. Impact of commercial and minimal scouting on usage of insecticides
and miticides by strawberry growers interviewed during impact study.


100

*o
680
~ / commercial scouting []
I A minimal scouting [
i 60







S+15.0* -5.0*
0 //
S20 /A
// +15.0* -5.0*


same increased reduce
Influence of scouting on fungicide usage on strawberries

* Average percent change in amount of fungicide used.
Figure 15. Impact of commercial and minimal scouting on fungicide usage by
strawberry growers interviewed during impact study.








relatively conservative spray practices may mean less margin exists
for reductions in pesticide use with this crop than for other crops.
About half the pepper growers using commercial scouts reported
that insecticide use was reduced (Fig. 12). Furthermore, the
reductions averaged about 50%. IFAS has had little direct involvement
in the favorable development recorded for IPM for pepper. This may
be an indication of the influence that private sector initiative can have
on development and adoption of IPM philosophy.
When commercial scouting is used on strawberry farms, a significant
reduction in use of insecticides and miticides is seen (Fig. 14). All
growers using commercial scouting reported a savings in applications
of these pesticides, with an average reduction of 27.5%. Only about
30% of the minimal-scouting growers reported reductions. This is a
good example of the reductions in pesticide usage that may be achieved
by use of formal IPM programs. Most of this savings is no doubt
in applications of pesticides for two-spotted spider mite. Again, the
private sector was involved in the development of sampling procedures
and action thresholds to be used in Florida. Close cooperation in the
future between IFAS and private pest management companies should
result in advances in pest management science of benefit to both the
university and the private sector. Such cooperation between IFAS and
private enterprise must be encouraged.











Chapter 3

Specific Questions Adressed to
Tomato Growers



Perceptions of tolerance to damage of foliage
Growers did not feel that tomatoes were very tolerant to partial
defoliation, responding, on the average, that plants could tolerate
only 9% defoliation before losses occurred. Four growers stated that
no defoliation at all could be tolerated. Keularts et al. (6) reported
that 30% or more defoliation was necessary to cause losses in yield
or quality of direct-seeded tomatoes. IFAS needs to emphasize the
relatively high tolerance of tomato to defoliation in future educational
programs. Such efforts may cause growers to use fewer pesticide sprays
to control subthreshold levels of foliar pests. Use of IFAS-recom-
mended defoliation thresholds was also fairly low only one grower
in four was using any kind of defoliation threshold when making spray
decisions.

FAIRS awareness
Thirty-nine percent of the growers were aware of the existence of
the Florida Agricultural Information Retrieval System (FAIRS).
Demonstrations and other efforts to make potential end users aware
of the existence and nature of the FAIRS data base have been
effective. What is even more significant, a strong interest in using
FAIRS exists among current non-users: over 82% of the growers said
they would like to have access to FAIRS. Therefore, the current efforts
by the FAIRS working group to set up field tests of the program are
both appropriate and timely.

Fumigation and nematode control
As expected, growers were heavily dependent on broad-spectrum
soil fumigants for control of nematodes. Almost 9 out of 10 growers
based their control programs on preplant fumigation (Table 5). Use
of preplant bioassay plants (7) was uncommon (8% of respondents).
The brominated hydrocarbon fumigants may be severely restricted in
the near future. Loss of these products will have a substantial impact
on the tomato industry. Alternatives to fumigants for control of








Table 5. Nematode control strategies reported as used by tomato growers.
Percentage growers
surveyed using various
Control program control strategies

Preplant fumigation 89.4
Preplant populations 2.1
Preplant bioassay plants 8.0
Assays during season 0.0
Previous crop condition 8.5
No control program 0.0


nematodes and other soil-borne pests must be sought, and long 40
range extension plans should include provisions to educate growers
about these alternatives.

Parasite mortality
Most growers were aware of the possible negative impacts of
broad-spectrum insecticides on beneficial insects; Eighty-five percent
of the respondents felt that they considered beneficial insects when
choosing a particular spray material. In addition, 53% felt that they
used information on the relative abundance of leafminer parasites when
making decisions about insecticide applications. These data verify that
IFAS has done a good job in educating growers on the possible
negative impacts of broad-spectrum pesticides on non-target organisms.

Streptomycin use
Streptomycin use is still fairly widespread in the tomato industry.
Almost 47% of the tomato growers used some streptomycin. This is
unfortunate considering the widespread occurrence of resistance to this
antibiotic among Florida strains of Xanthomonas campestris pv.
vesicatoria (Doidge) Dye (16, 17).

Summer field management practices
The majority of growers indicated that they kept their land fallow
during the summer offseason (Fig. 16). Cover cropping was used about
one-third of the time. Fields left in weed cover was a less common
practice. However, one in five growers let some fields develop a cover
of weeds. No growers used summer crops antagonistic to tomato pests,
probably reflecting the state of knowledge in this area.









100


e 80 -

c
2 60 -

0
0) 4
o

S20 /
20


fallow cover crop weed cover
Summer management strategies
Figure 16. Prevalence of several land management strategies used during the
non-cropping (summer) season.

Integrated management of bacterial spot
Growers were using most of the important strategies available to
them in attempts to minimize damage from bacterial spot (Table 6).
A surprisingly large percentage (42.6%) were using treatment of seed
with hypochlorite. The quantitative importance of seed in initiating
epidemics is still a matter of considerable controversy in Florida (4)
and in other states. More research is needed to better define the role
of seedborne inoculum in the epidemiology of bacterial spot.

Most important pest problems identified by growers
The most important pest problems identified by tomato growers are
shown in Tables 7-10. Leafminers were by far the insect problem
reported most frequently (Table 7). This is a pest of particular interest
to pest management. There is documented evidence of insecticide-
induced outbreaks of leafminers due to heavy mortality of leafminer
parasites (10, 21). Certainly, more demonstration work and other
educational effort is needed to show growers the impact of their own
insecticide use on the development of leafminer problems.
The responses "worms" and "pepper weevil" are interesting. They
indicate a need to offer (or continue to offer) programs that emphasize








Table 6. Practices used to minimize damage from bacterial spot and other
bacterial diseases on tomatoes as reported by growers surveyed during
the vegetable IPM impact survey.
Percentage of growers
surveyed using
Practice various practices

Hypochlorite treatment of seed 42.6
Avoidance of wet plants 89.4
Destruction of summer volunteer tomato plants 91.5
Application of copper and maneb (mancozeb) 80.9
Application of copper and maneb or other fungicide
depending on weather conditions and scouting reports 80.9


Table 7. Most important insect problems as reported by tomato growers during
the survey of the impact of IPM on grower practices.


Frequency (%) at which
each pest was recorded
as first or second most
important insect problem


Insect pest


Pinworm 38.2
Leafminers 97.8
Fruitworm 21.2
Armyworm 2.1
"Worms" a 17.0
Cutworm 2.1
Aphid 2.1
Pepper weevil 2.1

a. Colloquial term appearing on survey form.

the proper identification of pests. It makes a great deal of difference
what particular caterpillar is infesting a field if one is to choose the
most efficacious insecticide at the minimum effective rate to preserve
communities of beneficial organisms. "Worms" is often not specific
enough an identification. The "pepper weevil" response may very
well represent a misunderstanding during the interview process.
Perhaps the grower also produced pepper where pepper weevil damage
is common. Similar damage on tomato may have been ascribed to
pepper weevil.








As expected, bacterial spot was identified overwhelmingly as the
most important disease problem (97.8%) (Table 8). Late blight was
also considered a fairly serious problem (36.1%), although it has not
been observed by IPM personnel since about 1979. It is very difficult
to predict accurately outbreaks of potentially devastating late blight.
Grower concerns about this disease might be alleviated to a degree,
if disease prediction systems adapted to Florida could be developed
(13).
Most growers did not view nematodes as a serious problem at this
time (Table 9). This probably reflects good control by the readily
available broad-spectrum soil fumigants as noted previously. This
situation could change dramatically, of course, if these materials are
regulated off the market.

Table 8. Most important disease problems as reported by tomato growers during
the survey of the impact of IPM on grower practices.


Frequency (%) at which
each disease was recorded
as first or second most
important disease problem


Disease


Bacterial spot 97.8
Bacterial speck 6.3
Early blight 21.2
Late blight 36.1
Fusarium crown rot 8.5
Bacterial wilt 2.1
Leaf mold 2.1


Table 9. Most important nematode problems as reported by tomato growers
during the survey of the impact of IPM on grower practices.

Frequency (%) at which
each nematode was recorded
as first or second most
Nematode important nematode problem

Root-knot 8.51
Sting 8.51
Stunt 2.12
Stubby-root 2.12








Statewide, nightshade was listed as the most serious weed problem
(Table 10). As expected, there were large regional differences in the
relative importance assigned to given weeds. In Dade county, Par-
thenium was viewed as the number one weed problem; this weed is
less abundant in other tomato-growing areas. In Collier county, 100%
of the growers listed nightshade as one of the most important problems.
Pigweed was listed as a serious problem by Manatee growers nearly
as often as nightshade.

Table 10. Most importantweed problems as reported bytomato growers during
the survey of the impact of IPM on grower practices.

Frequency (%) at which
each weed was recorded
as first or second most
Weed important weed problem
Nightshade 63.8
Pigweed 36.1
Foxtail 2.1
Nutsedge 23.4
Parthenium 10.6
Purslane 2.1


Generally speaking, the growers' perceptions of the "most serious"
pest problems matched fairly well the perceptions of extension and
research faculty. Because IFAS seems to be aware of the pressing
problems facing producers, educational programs are probably already
directed towards the areas of critical need. This study provides
evidence that the programs are relevant and timely.







Chapter 4

Specific Questions Addressed to

Snap Bean Growers



All snap bean growers interviewed were either in Dade or Hills-
borough counties.

Nematode control
Not many bean growers used the nematode control tactics identified
in the survey (Table 11). The fact that one-third of the growers said
that they had no control program may reflect a lack of registered
chemical control alternatives. Certainly more growers could be using
estimates of nematode population densities and the condition of previous
crops to aid in making decisions about nematode control. Preplant
fumigation has not proven to be economically feasible in field tests
in the Homestead area (8), probably accounting for the low incidence
of preplant fumigation recorded in this study. In addition, no growers
were using bioassay plants for preplant assessment of rootknot nema-
todes. Extension agents may want to include more information on
this simple and very useful bioassay technique (7).

Table 11. Nematode control strategies used by snap bean growers as reported
during survey of the impact of IPM on grower practices.
Percentage of growers surveyed
Control program using various control strategies
Preplant fumigation 8.3
Preplant counts 8.3
Preplant bioassays 0.0
Assays during season 25.0
Previous crop condition 25.0
No control program 33.3


Perception of tolerance to foliar damage
Despite considerable effort to inform growers of the tolerance of
snap beans to partial defoliation, the tolerance of the crop was woefully








underestimated. On the average, growers felt that beans could tolerate
11% and 0% defoliation pre- and post-bloom, respectively. These levels
are considerably below the 20% and 10% levels recommended by IFAS
(20). This is an area where we would hope to see more progress
during the next five years.

Bacterial diseases of bean
Growers demonstrated a general lack of knowledge about the
epidemiology and control of bacterial diseases. Resistant varieties were
rated as the highest priority for control (Fig. 17). Unfortunately, there
isn't much difference in commercial bean varieties in susceptibility
to common blight (our most important bacterial disease). Foliar
application of copper was the second tactic of choice. The efficacy of
copper treatments for bacterial blight is extremely questionable.
This practice has not been particularly advocated by the Florida
Cooperative Extension Service. The two most useful treatments,
disease-free seed and avoidance of movement in wet fields, were rated
least important by growers. Obviously this is an area where more
education is necessary.



4




3 -




2




disease apply minimal resistant
free seed copper movement varieties
Control tactics

Figure 17. Grower ranking of importance of factors in the control of bacterial
diseases of snap beans (1 = highest priority; 4 = lowest priority).








Nematode problems and cropping season
Growers considered nematode problems to be independent of crop-
ping season (Question 6). One-third of the growers thought nematode
control to be more important in the fall and another one-third thought
spring infestations were more important. Twenty-five percent felt that
the need for control was the same in the fall and spring. Researchers
generally feel that the threat from nematodes is greater in the spring
cropping season on double-cropped beans following beans or squash.

Chemical control of Rhizoctonia root rot
Chloroneb fungicide has long been recommended as an important
part of a management program for the root rot complex affecting snap
beans. This material is particularly effective against Rhizoctonia, the
primary pathogen in this fungal complex in southern Florida. In the
past, in-furrow spray treatment has been emphasized as the most
effective method of application. Only 50% of the growers used
chloroneb in some way (Table 12). Among those using chloroneb,
most (67%) used it as a hopper box treatment. The other 33% applied
the material in-furrow as recommended. Since the time of the survey,
the in-furrow use of chloroneb is no longer a labeled use.

Table 12. Chloroneb control of Rhizoctonia disease as reported by snap bean
growers.

Percentage of all growers surveyed using chloroneb ...... 50.0
Of growers who use chloroneb,
percentage using hopperbox treatmenta ............ 67.7
percentage using in-furrow spray ................. 33.3

a. Hopperbox treatment: chloroneb applied dry to seed in the seed planter and mixed
thoroughly just prior to planting.


Timing for white mold control
White mold, caused by Sclerotinia sclerotiorum (Lib.) d By., is a
serious problem on beans, especially in Dade County Florida. How-
ever, the disease is primarily a cool season problem. During the fall
season (early September late October) another disease, Pythium
aerial blight, has often been misdiagnosed as white mold (20). While
the symptoms of the two diseases can be confused easily in the field,
they can be differentiated readily by microscopic examination of the
causal fungus. These misidentifications often have led to unnecessary
and expensive applications of benomyl (or other specific fungicides)








for non-existent white mold problems. In our experience, white mold
normally does not become a problem until November. Before that
time, "white mold epidemics" are invariably outbreaks of Pythium
aerial blight, for which no fungicide treatment is particularly effective.
Educational efforts have been made over the last several years to
address the confusion in diagnosis of these two diseases; however,
the survey results suggest that further education is needed. Many
growers continue to begin benomyl sprays in October (Fig. 18).
Seventeen percent of the growers initiated sprays of benomyl in
September to control Sclerotinia. One grower surveyed was already
using benomyl in August. A concerted effort needs to be made to
educate growers on the need to seek assistance from agents, scouts,
or state specialists with access to a microscope. Once proper diagnosis
is made, growers need more information on the best control measures
to be used for their specific problem. If at least 60% of the growers
delay spraying for control of Sclerotinia until November, about three
sprays of benomyl or similar compounds could be saved on 5000 acres
of fall beans.


Figure 18. Month in which snap bean growers begin spraying benomyl (or
other specific fungicide) for control of white mold (Sclerotinia
sclerotiorum).








Plant spacing and pest management
A considerable amount of research has been done at the Tropical
Research and Education Center on the relationship between pest density
and plant arrangement for optimal snap bean production. Both
in-row and between-row spacings have been investigated. These studies
have sought to determine which spacings minimize pest damage while
maximizing yields per acre. Results suggest that between-row spacing
can be reduced from the 36-inch distance recommended previously.
With closer spacing, yields are increased with no adverse change
in pest incidence and severity. However, it has been shown clearly
that an increase from 1 inch to 3 to 4 inches between plants in a row
significantly reduces damage from Sclerotinia and other pests. Most
growers (75%) are still using a between-row spacing of 36 inches
(Fig. 19). However, ongoing educational programs have resulted in
some closer between-row spacings on some farms (25% of the growers
used predominantly 24 or 18 inches). In informal interviews, these
growers have indicated substantial yield increases and no adverse pest
problems.
All growers are currently planting beans 1 to 2 inches apart in the
row (Fig. 20) even though this is conducive to white mold, nematodes,
and several other important bean pests. Optimizing bean spacing
within the row may have to await the integration of damping-off and
root rot and hypocotyl rot control (caused primarily by Rhizoctonia
solani Kuehn) with cultural control of these other pests. Growers
presently seed heavily in the row to make up for stand reductions due
to damping-off. To date, attempts to control damping-off and root rots
have met with little success (Pohronezny, unpublished). In order to
bring about increases in the in-row spacing, growers will need an
effective control for these soilborne diseases. Demonstration-research
trials in this area will need to be continued. Once growers are
convinced that is it safe to seed less heavily, 3- to 4-inch in-row
spacings will more likely be used as a cultural management tool for
Sclerotinia and other pests.

Fungicide residues on Florida beans destined for Canada
In recent years, Canadian agricultural and regulatory officials have
expressed a great deal of concern about the residues of ethylene
bisdithiocarbamate (EBDC, from commonly used fungicides such as
maneb and zineb) on snap beans intended for sale in Canada. The
Canadian tolerance for EDBC is only 0.1 ppm compared to the U.S.
tolerance of 7 ppm. Up to 20% of all Florida beans are marketed in
Canada in a given year. Florida growers depend quite heavily on
maneb, zineb, or other EBDC fungicides for disease control. In par-










100 -



80 -



60 -



40 -



20 -



0 _


3 30 24 18
Between-row spacings (in.)

Figure 19. Between-row crop spacing (inches) used by snap bean growers
surveyed in the study of the impact of IPM on grower practices.


100

4)

S80



io-
60
0





IL 20
0
C




.L
U_ 0


1 2 3
Within-row spacings (in.)


4


Figure 20. Within-row crop spacing (inches) used by snap bean growers sur-
veyed in the study of the impact of IPM on grower practices.








icular, control of bean rust, potentially one of our most devastating
bean diseases, has been achieved primarily by season-long sprays of
maneb and sulfur tank mixes.
IFAS developed a viable program in response to grower needs
(11). It is recommended that maneb and sulfur be sprayed until
flowering. Chlorothalonil sprays (chlorothalonil has a 5 ppm tolerance
in both Canada and the United States) is then used for the remainder
of the season. Growers using this approach can expect to meet
tolerance limits for EBDC imposed by Canada.
At the time of the survey, most growers were still spraying maneb
and sulfur throughout the season (including post flowering) (Table
13). A small percentage (16.7%) had already changed to the recom-
mended post-flowering chlorothalonil regime. The percentage of com-
pliance has increased in the last year (Pohronezny, unpublished). Even
though a considerable effort had already been made by the Florida
Cooperative Extension Service to effect this change, there is a need
to continue to emphasize these recommendations in ongoing educational
programs. The confidence of Canadians in the acceptability of Florida
snap beans may well rest on 100% compliance by growers.

Table 13. Rust control strategies used by snap bean growers as reported during
survey of the impact of IPM on grower practices.
Percentage of growers
Chemical surveyed using various
control program control strategies

Maneb until preharvest limit 8.3
Maneb & sulfur until preharvest 75.0
Chlorothalonil until preharvest limit 0.0
Maneb or maneb & sulfur until flowering,
followed by chlorothalonil 16.7
Other regimen 0.0


Predator/parasite mortality
As with tomatoes, IFAS has been fairly successful in making growers
aware of the importance of beneficial insects in the integrated
management of insect pests. Somewhat more than one-half of the
growers said that they considered the status of beneficial insects
(parasites and predators) in making decisions to control leafminers.








Most important pest problems Identified by growers
Leafminers were viewed by growers as the most important insect
pest affecting their crop (Table 14); they were mentioned more than
twice as often as the second insect on the list. Presently, there are
no registered insecticides which are still effective against leafminers
on snap beans. However, demonstration-research plots have shown
repeatedly the benefits of "scout-and-spray" tactics for conservation,
and subsequent management, of leafminers on snap beans (20). In-
creased emphasis on scouting is needed, along with registration of
an effective insecticide that can be used when action thresholds are
reached.

Table 14. Most important insect pests as reported by snap bean growers during
the survey of the impact of IPM programs on grower practices.

Frequency (%) at which each pest
was recorded as first or second
Insect pest most important insect problem

Leafminers 58.3
Cabbage loopers 25.0
Mites 8.3
Stink bugs 16.7
"Worms" a 16.7
Thrips 8.3
Armyworms 8.3

a. Colloquial term appearing on survey form.

Growers considered white mold (Sclerotinia) and rust to be their
most important disease problems (Table 15). Some mention also was
made of Rhizoctonia root and hypocotyl rot and Alternaria leaf spot.
We feel that Rhizoctonia and other soilborne fungus problems are
probably a lot more important than growers perceive them to be. The
damage from these diseases is less readily observed (symptoms are
primarily below ground). Insidious, chronic levels of root disease can
cause serious losses without the overt signs associated with Sclerotinia,
rust, or other above-ground problems. Growers need to made more
aware of the importance of soilborne pests. Additional demonstra-
tion-research activity is needed to find the best management practices
to deal with these problems.








Table 15. Most important disease problems as reported by snap bean growers
during the survey of the impact of IPM on grower practices.
Frequency (%) at which each disease
was recorded as first or second
Disease most important disease problem

White mold (Sclerotinia) 58.3
Rust 58.3
Alternaria leaf spot 16.7
Rhizoctonia root and hypocotyl rot 16.7
Damping-off 8.3


Nematodes are not perceived as an important class of pests. Many
growers did not identify any specific nematodes on the survey forms.
Root-knot nematode was listed by 25% of the growers (Table 16), and
sting nematode was mentioned by one respondent. No one listed
reniform nematode, even though McSorley et al. (9) have shown that
the reniform nematode is potentially quite damaging on Rockdale soils.
Nematodes are probably not perceived as important because of the
insidious nature of the damage (with the notable exception of root-
knot nematode). This situation might be improved through increased
emphasis on nematode biology and control at grower meetings and
in various newsletters.

Table 16. Most important nematode problems as reported by snap bean growers
during the survey of the impact of IPM on grower practices.
Frequency (%) at which each nematode
was recorded as first or second
Nematode most important nematode problem

Root-knot 25.0
Sting
8.3


Quite a number of different weed problems were listed by growers
(Table 17). Pigweed was reported most frequently (58.3%), followed
by ragweed (33.3%), Parthenium (28.6%), and purslane (16.7%).
Parthenium continues to be a difficult problem in most vegetable crops
in Dade County. Parthenium control is a viable area for IFAS research.








Table 17. Most important weed problems as reported by snap bean growers
during the survey of the impact of IPM on grower practices.


Frequency (%) at which each weed
was recorded as first or second
most important weed problem


Pigweed 58.3
Ragweed 33.3
Parthenium 28.6
Purslane 16.7
Mustard 8.3
Nutsedge 8.3
Grasses 8.3
Nightshade 8.3


Weed







Chapter 5

Specific Questions Addressed to
Strawberry Growers




All data on strawberry IPM practices were gathered in Hillsborough
and Manatee counties. These are the major strawberry producing areas
of Florida with a minimum of roadside and/or U-PIC operations in
the other study counties.

Preplant inspection of transplants
Most of the strawberry growers (69%) had plants inspected for one
or more pests before they accepted delivery to their farm. This is a
sound IPM practice and should contribute immensely to the production
of a quality crop. With lower initial pest populations, dependence on
field application of pesticides should be reduced. Perhaps future Florida
Cooperative Extension Service programs should concentrate on the
31% of the strawberry growers not using this important management
practice. It should be relatively easy to convince these growers of the
value of clean transplants to pest management programs.

Pest management and field site selection
A similar number of growers said that they used neither previous
nor neighboring crop type in land-selection decisions. Thus, pest
management practices are subjugated to the need to secure available
land for rent.
The majority of growers (53.8%) reported that land availability was
highly important in their selection of locations to farm (Table 18).
If land constraints continue during the next five years (and at pres-
ent, there appears little reason to think otherwise), there may be little
chance to modify decision-making on the basis of choice of land.

Market-driven adjustments in pest management costs
The study team thought that strawberry growers might adjust the
expenditure of time and money for pest control depending upon the
expected value of the harvested crop. This hypothesis was not borne
out by the data. About 83% of the growers seldom or never adjusted
their pest control expenditures as the expected prices of the crop








Table 18. Ratings of the relative importance of three factors in selection by
growers of a site for production of strawberries.

Percentage of growers reporting
positive response in each category
Factor Not at all Little Moderate High

Previous crop type 53.8 23.1 7.7 15.4
Neighboring crop type 53.8 38.5 0.0 7.7
Availability of land 23.1 15.4 7.7 53.8



changed (Fig. 21). No growers used such a decision-making process
frequently. The crop may be of too high a baseline value and the pest
management art at present too rudimentary for growers to risk pest
control modifications. Alternatively, the vagaries of the marketplace
may make it difficult for growers to gauge expected prices.

Perception of interactions between fields
About 50% of the growers felt that neighbors' pest problems had
little or no effect on their own crops. This philosophy is counter to



I inn I


C

0.
*I 80 -
o

so-
06
60-
0

0S 40-

ao
a. 20 -
rL 0

I1a.0O


never seldom often
Frequency of adjustment


most always


Figure 21. Prevalence of adjustments of expenditures by strawberry growers based
on anticipated price changes for crops.








that of many IFAS pest management professionals. Pest management
practices on nearby farms may impact greatly on each grower's control
efforts. The lack of awareness of between-field pest dynamics should
be addressed in future educational programs.

Anthracnose resistance and cultivar selection
Anthracnose damage to fruit has been a very serious problem for
Florida producers over the past several seasons. Growers have been
using frequent applications of fungicides in an attempt to control the
disease. This has proven to be very expensive and has contributed
to residue problems, particularly on fruit intended for market in
Canada. Generally speaking, Canadian tolerances for fungicides are
lower than those established by U.S. law. Since as much as 25% of
all Florida strawberries are marketed in Canada, it is important that
agricultural interests in our state be aware of Canadian concerns.
We feel that the anthracnose problem on strawberry fruit is, to a
great extent, associated with the current widespread use of cultivars
developed in California (e.g., 'Paharo'). Many of these cultivars are
highly susceptible to anthracnose much more so than are many
selections developed in Florida. However, growers apparently choose
to use the highly susceptible cultivars, because they produce very large
berries, with high market appeal. This was borne out by grower
responses.
Anthracnose resistance was not one of the highest priority attributes
in selection of a cultivar (Table 19). Ranked ahead of resistance (in
order) were earliness, brokers' market preference, and yield. Fruit
size and flavor were both rated less important than anthracnose
resistance.

Table 19. Relative importance of six attributes in the selection of a strawberry
cultivarforcommercial production as reported bygrowers participating
in a study of the impact of IPM programs on grower practices.

Attribute Relative ranking
Earliness 25
Anthracnose resistance 47
Fruit size 56
Flavor 75
Brokers' market performance 32
Yield 38
a. Each attribute ranked from 1 to 6, where 1 = highest priority and 6= lowest priority.
Numbers are totals of all rankings of all growers surveyed.








These data strongly suggest that growers are selecting their cultivars
on the basis of horticultural characteristics and buyer preferences,
rather than anthracnose resistance. Use of strawberry varieties
developed in Florida may be the long term answer. Anthracnose
resistance should be incorporated into cultivars with high yields,
earliness, and high appeal to produce brokers.

Predatory mites
Pest mites (particularly two-spotted spider mites, and, more recently,
cyclamen mites) are consistently some of the most serious problems
facing Florida strawberry growers. At the present time, no growers
report releasing beneficial mites to control problem mites. However,
77% of them said they would release such predators in lieu of chemical
miticides, if they were available.
Commercial releases of predatory mites in Florida have been
hampered by the need to control flower thrips. The latter pest, and
spider mites, usually invade strawberry crops about the same time.
Flower thrips are controlled by periodic applications of broad-spectrum
insecticides, which also may depress populations of predatory mites.
A scheme to integrate control of flower thrips and spider mites is
needed.

Nematode control
The strawberry industry currently is heavily dependent upon
broad-spectrum fumigants to control nematodes and other soilborne
pests. One hundred percent of all growers surveyed relied exclusively
upon preplant fumigation for nematode control. As long as the
brominated hydrocarbons continue to be available, growers probably
will continue to depend upon soil fumigation for control of most of
their soilborne pests. However, the Environmental Protection Agency
may rescind registrations of these compounds in the future. If that
occurs, other treatment tactics will have to be used, and research and
educational programs should concentrate on these other control
strategies. Appropriate action can then be taken quickly if the
regulatory situation should change.

Fungicide residues on strawberries
intended for sale in Canada
Canada buys about 25% of the strawberries grown in Florida. As
with snap beans, Florida strawberries occasionally have residues of
several fungi-cides which exceed tolerances established by Canada.
Of particular concern is captain. Several shipments of Florida
strawberries have been refused at the Canadian border because of








captain residues in excess of Canadian tolerances even though they are
within U.S. tolerance levels.
More than 75% of Florida growers depend heavily upon captain for
control of the major foliar diseases. Benomyl and thiophanate methyl
were the second and third most frequently listed choices (15 and 8%
respectively). Obviously, some dialogue is needed between Canadian
regulatory personnel and the Florida vegetable industry to attempt
to reconcile grower needs with health concerns of Canadians.
Demonstration-research efforts by county agents and specialists should
be considered in order to find alternative fungicides. These fungicides
should be chosen, if possible, so that future conflicts with the important
Canadian trade are minimized.

Most important pest problems identified by growers
Mites were viewed by producers as the most important "insect"
pest of strawberry. More than 90% of those interviewed listed mites
as the most serious pest (Table 20). Budworms and flower thrips
were each listed 38.5% of the time. These perceptions match fairly
closely those held by IFAS extension and research personnel. Also,
sampling for mites constitutes the primary thrust of private pest
management personnel.
Anthracnose damage to the fruit was seen as the most serious disease
problem; it was listed by 69% of the growers interviewed (Table 21).
Other diseases mentioned included Botrytis blight, angular leaf spot
(bacterial disease), anthracnose foliar damage, and common leaf spot.
IFAS workers also have noted the importance of anthracnose fruit
damage, and a major research and educational effort is underway to
address this problem. As noted earlier, an important component of
this effort is the development of cultivars with anthracnose resistance,
large fruit size, and market appeal.

Table 20. Most important insect pests as reported by strawberry growers during
the survey of the impact of IPM on grower practices.
Frequency (%) at which
each pest was recorded
as first or second most
Insect pest important insect problem

Mites 92.3
Budworm 38.5
Flower thrips 38.5
Lesser cornstalk borer 7.7









Table 21. Most important disease problems as reported by strawberry growers
during the survey of the impact of IPM on grower practices.

Frequency (%) at which
each disease was recorded
as first or second most
Disease important disease problem

Botrytis blight 15.4
Angular leaf spot 23.1
Anthracnose fruit 69.2
Anthracnose leaves 23.1
Common leaf spot 23.1


As with other crops where broad-spectrum fumigants are used,
nematodes were not viewed as serious threats to production at this
time (Table 22). Low frequencies of the following nematodes were
reported as problems: root-knot, sting, and "bud" nematode (Aph-
lenchoides fragariae (Ritzema Bos) Christie). Of course, nematode
problems, particularly sting nematode, would become much more
serious if the brominated hydrocarbon fumigants were no longer
available.

Table 22. Most important nematode problems as reported by strawberry growers
during the survey of the impact of IPM on grower practices.

Frequency (%) at which
each nematode was recorded
as first or second most
Nematode important nematode problem
Root-knot 7.7
Bud 7.7
Sting 15.4


A wide range of responses was received to inquiries about weed
problems. Nutsedge was listed as an important problem by 46% of
the growers (Table 23). Other weed problems listed by one or more
growers included pigweed, purslane, nightshade, dogfennel, clover, and
redshankk" (probably red root pigweed).









Table 23. Most important weed problems as reported by strawberry growers
during the survey of the impact of IPM on grower practices.


Frequency (%) at which
each weed was recorded
as first or second most
important weed problem


Nutsedge 46.2
Nightshade 15.4
Pigweed 23.1
Dogfennel 15.4
Clover 15.4
Purslane 23.1
Redroot pigweed 7.7


Weed











Chapter 6

Specific Questions Addressed to

Pepper Growers



Weevil management on pepper
Data from Collier, Manatee, and Hillsborough Counties were used
in the profile for pest management practices on pepper. Pepper
weevil is the most serious insect pest of pepper statewide. Con-
siderable direct damage to fruit can occur. Chemical control alone
is often inadequate to prevent economic losses, even though current
control measures primarily depend upon periodic applications of
insecticides.
Many growers are using recommended cultural practices for pepper
weevil management (Table 24). Prompt crop destruction and black
nightshade control are practiced widely. Destruction of cull fruit is
less often reported.

Table 24. Practices used to control pepper weevil.
Percentage of
growers surveyed
using
Practice various practices
Prompt destruction of crop after last harvest 100.0
Destruction of culls 27.3
Maintenance of minimum level of control during U-Pic operations 9.1
Control of in-field and field-border infestations of black nightshade 54.5


Minimum levels of weevil control usually are not maintained in
U-Pic operations. This may reflect the obvious restrictions imposed
upon growers in fields visited daily by the public. The contributions
of U-Pic field infestations to area-wide weevil activity should be
evaluated in economic terms. The extra income generated by U-Pic
operations should be compared to industry-wide risks of production
field losses.








Use of streptomycin
Streptomycin is used less frequently among pepper growers than
among tomato growers. Only 7.5% of the respondents used any
streptomycin, compared to 47% for tomato growers (Chapter 3).
These data correlate quite well with use patterns for streptomycin
reported by Sonoda and Pohronezny (16). The occurrence of strep-
tomycin-resistant isolates of Xanthomonas campestris pv. vesicatoria
(Doidge) Dye was much more prevalent in tomato fields than in pep-
per fields (16). This suggests that tomato growers historically have
exerted more selection pressure upon populations of X campestris
pv. vesicatoria than have pepper growers. Florida Cooperative
Extension Service programs can use these data to encourage pepper
growers to continue wise use of streptomycin. Emphasis can be placed
upon the risk of resistance associated with overuse of agricultural-grade
antibiotics.

Selection of pepper cultivars
Horticultural traits dominated the criteria used in selection of a
pepper cultivar (Fig. 22). Yield and fruit shape and size were rated
most important in variety selection. Although host plant resistance


5



4-




a /////


0 2



fruit shape virus earliness yield
set & size resistance
Cultivar traits

Figure 22. Factors involved in selection of a pepper cultivar by growers sur-
veyed during the IPM impact study ranked in order of importance
by growers (1 = highest priority; 5 = lowest priority).








is a major strategy for management of virus diseases, virus resistance
was a relatively low priority. More work is needed to determine why
producers do not view virus resistance more strongly when selecting
a cultivar.

Management of bacterial spot
Bacterial spot is a severe problem on pepper as well as on tomato.
At the present time, no growers reported that they were using
hypochlorite seed treatment as part of their bacterial spot control
programs (Table 25) (contrasting sharply with data for tomato growers,
Table 6). The quantitatively important sources of primary inoculum
of bacterial spot are still a matter of considerable debate. Use of seed
treatment assumes that seed is an important source of inoculum.
There is more positive evidence for seed transmission of X campestris
pv. vesicatoria in pepper than in tomato (4); however, the question
of relative importance of seed transmission in both crops is far from
resolved. Most pepper seed is probably treated with hypochlorite by
the seed companies before sales to growers (Dan Cantliffe, personal
communication). Therefore, it appears that additional seed treatment
by individual pepper growers is not warranted at this time.
Growers follow most of the recommended practices for the integrated
management of bacterial spot (Table 25). However, the continued
widespread destruction caused by this disease provides incentive to
continue a strong research effort in IFAS aimed at improved control
of bacterial spot.

Table 25. Practices used by growers surveyed during the study of the influence
of IPM programs on grower practices to minimize damage from bacterial
spot and other bacterial diseases of pepper.
Percentage of
growers surveyed
using
Practice various practices

Hypochlorite treatment of seed 0.0
Avoidance of wet plants 81.8
Destruction of summer volunteer pepper plants 72.7
Application of copper and maneb (mancozeb) 63.6
Application of copper and maneb or other fungicide
depending on weather conditions and scouting reports 100.0








Nematode control
All pepper growers surveyed said they were using preplant
fumigation for nematode control. This practice provides broad spectrum
control of most soilborne pests. It is obviously an important component
of the pepper production system. The possible removal of all bromi-
nated hydocarbon fumigants by the EPA would have a severe impact
on the Florida pepper industry. Cost/benefit analyses may be
warranted in order to provide data on the economic consequences of
cancellation of registrations for methyl bromide and other fumigants.
Decision-making patterns for nematode control by growers reflects
the ready availability and effectiveness of broad-spectrum fumigants.
Most growers surveyed made no particular effort to assess the potential
impact of nematodes on their crops prior to control decisions (Fig.
23). The broad-spectrum fumigants give growers excellent control of
weed seed, soilborne pathogens, and insects, as well as nematodes.
Therefore, it is unlikely that pepper growers will deviate a great deal
from the full-bed, fumigation, plastic-mulch production system. If these
fumigants become unavailable growers may have to consider alternative
management strategies for soilborne pests. The technology to make
informed decisions is fairly well outlined and available to extension
personnel for incorporation into educational programs as needed.


100


j 80 -


60 -
o 40

40


C0 2
0//
0 ////



prior to during previous none
planting planting planting taken
Timing of sampling

Figure 23. Timing of sampling by growers for informed nematode control.








Most important pest problems identified by growers
As expected, pepper weevil was reported most frequently as a major
insect pest of pepper (Table 26). This insect is an excellent candidate
for research on sampling and action thresholds. Pepper weevil attacks
fruit directly, causing considerable damage unless vigilantly controlled.
Therefore, pepper weevil is one of the primary reasons that IFAS
workers have been reluctant to institute IPM programs in this crop.
More sophisticated sampling methods (e.g., pheromone trapping) may
be needed in order to properly apply scout-and-spray strategies for
weevil.

Table 26. Most important insect pests as reported by pepper growers during
the survey of the impact of IPM on grower practices.
Frequency (%) at which
each pest was recorded
as first or second most
Insect pest important insect problem
Pepper weevil 63.6
Armyworm 27.3
Pinworm 9.1
"Worms" a 36.4
Aphid 36.4
a. Colloquial term appearing on survey form.

Growers also voiced major concerns about lepidopterous pests in
pepper armywormss and "worms" in Table 26). Aphids (vectors of
most pepper viruses) also were viewed as fairly important.
Not surprisingly, 100% of the growers listed bacterial spot as their
most important disease problem (Table 27). No other disease was
identified consistently in the survey. Several growers reported
problems with Pythium blight. We would think that Phytophthora
blight, caused by Phytophthora capsici Leonian, is a more important
disease than Pythium blight. It may be that reports of Pythium blight
have indeed been outbreaks of Phytophthora blight. Apparently, virus
outbreaks (which do tend to be sporadic from year to year) were not
particularly serious during the time of this survey relative to other
periods (Table 27). However, serious losses due to virus diseases of
pepper are well documented (22).









Table 27. Most important disease problems as reported by pepper growers
during the survey of the impact of IPM on grower practices.

Frequency (%) at which
each disease was recorded
as first or second most
Disease important disease problem

Bacterial spot 100.0
Southern blight 9.1
Damping off 9.1
Pythium blight 18.2
Viruses 9.1


Over 90% of the respondents listed black nightshade as a problem
weed (Table 28). Other weeds listed included nutsedge, ground cherry,
lambsquarters, pigweeds, and purslane. However, reported frequencies
of all these weeds were relatively low.

Table 28. Most important weed problems as reported by pepper growers during
the survey of the impact of IPM on grower practices.


Frequency (%) at which
each weed was recorded
as first or second most
important weed problem


Black nightshade 90.9
Nutsedge 27.3
Ground cherry 9.1
Lambsquarters 9.1
Pigweeds 27.3
Purslane 9.1


More and more interest in scouting peppers is being generated in
Florida (Kathy Carbeiner, personal communication). Hopefully, the
base line information in this report will help formulate plans by both
extension and research to address IPM needs in this crop.


Weed








Chapter 7

Summary Remarks




The positive impact of integrated pest management on vegetable
production in southern Florida has exceeded our expectations. A
conscious effort was made to control bias that would unfairly represent
IPM in a positive light; however, the positive results of IPM efforts
by IFAS are demonstrated clearly. For example, about four out of
every 10 acres of tomatoes are now scouted by extension-trained
professionals. Growers find that commercial scouting is a sound
financial investment. Savings of over $100/acre, after scouting fees
(about $30.00/acre) commonly were reported by tomato growers. These
figures ought to be a source of gratification to all IFAS workers involved
in the development of IPM programs on vegetables.
Benefits to growers involve more than the traditional savings in
spray costs. Across the board, growers listed early and accurate pest
identification as the most desirable benefit of IPM. This aspect of IPM
needs more emphasis in discussions with policy makers and funding
sources. IPM is an important tool used by Florida growers to produce
a high quality, saleable commodity. It is a product that can compete
economically with Mexico, California, and the Caribbean Islands. As
an added benefit, Florida vegetables are often sprayed less where IPM
tenets are used. Considering turnover in pest management personnel
and county staff, more programs on pest identification are warranted.
Since most private IPM companies now have access to microscopes,
training in identification of fungi and other plant pathogens may be
appropriate.
Additional benefits accrue from commercial scouting programs.
Some growers who used only a minimal form of monitoring still
realized cost savings and improvements in crop quality. If IPM is
equated with commercial scouting, industry-wide benefits from pest
management programming by IFAS can be underestimated.
In some cases, little change has occurred where efforts by IFAS
have been considerable. For example, many tomato growers still
use streptomycin sprays, even though plant pathologists have known
for a long time that resistance in populations of the pathogen to this
material is widespread. In another case, snap bean growers have been
cautioned repeatedly about the need to differentiate between Pythium
aerial blight and white mold (Sclerotinia). Despite these efforts, some








growers still apply fungicides to control Sclerotinia when Pythium is
the problem. The present survey provides much-needed objective
feedback on actual attitude and behavioral changes.
It would be virtually impossible for IFAS to address all IPM needs
on all vegetable crops in southern Florida. However, the results of
the survey indicate that the private sector will initiate scouting
activities in new crops without necessarily waiting for IFAS to develop
sampling schemes and other system components. IFAS should expend
some effort in each geographical area for a number of crops deemed
adaptable to an IPM approach. This policy will recognize the needs
of both the growers and the rapidly emerging agribusiness of profes-
sional scouting and consulting.
Growers tend to rank pest problems (insects, diseases, nematodes,
and weeds) in the same order of relative importance as do IFAS
extension workers. Therefore, most Florida Cooperative Extension
Service programs are targeting areas of most concern to growers. Little
redirection is indicated. County programs need to emphasize current
research results so that growers will have the latest information with
which to combat these pests.
The survey was a hard-earned lesson in the problems of data
collection and management. Since the number of growers in any of
the four commodities is small, virtually all must be interviewed if
statistical analyses are to be applied to the data. It was impossible
to collect data from all growers. However, a large portion of the
acreage was represented in the data by assuring that most large-size
farms were visited. Therefore, even though statistical tests cannot
be applied, we feel that the recorded responses are truly reflective
of industry attitudes and practices.
Collecting, collating, tabulating, and interpreting the data were
time-consuming, laborious tasks. We found that writing a computer
program specifically tailored to the questionnaire saved time and effort
in the long run. The complexity of this program is such that the task
is not for the programming faint-of-heart. Of course, if another survey
is done in the future using similar questions, a large part of the
framework for data management is already in place.
Some of the information in this report can be interpreted as a
statement on the total crop management viewpoint of the grower.
For example, in some cases, host plant resistance is the only practical
means of pest control. Yet growers often do not rate resistance as
the major criterion in cultivar selection. Traits such as fruit size and
total crop yield are deemed more important. We see the possibility
that surveys of the future may be even more encompassing and
ambitious than the present one. These surveys will likely come under
the new acronym, ICM Integrated Crop Management.









Literature Cited
1. Getz, W. M., and A. P. Guiterrez. 1982. A perspective on systems
analysis in crop production and insect pest management. Ann. Rev.
Entomol. 27:447-466.
2. Guzman, V. L., W. G. Genung, D. D. Gull, M. J. James, and T. A. Zitter.
1979. The first four years of integrated pest management in Everglades
celery: Part II. Proc. Fla. State Hort. Soc. 92:88-93.
3. Harris, M. K. 1983. Integrated pest management of pecans. Ann. Rev.
Entomol. 28:291-318.
4. Jones, J. B., K. L Pohronezny, R. E. Stall, and J. P. Jones. 1986.
Survival ofXanthomonas campestris pv. vesicatoria in Florida on tomato
crop residue, weeds, seeds, and volunteer tomato plants. Phytopathology
76:430-434.

5. Jones, J. P. 1978. Disease thresholds for downy mildew and target
spot of cucurbits and late blight of tomato. Plant Dis. Rep. 62:798-802.

6. Keularts, J., V. Waddill, and K. Pohronezny. 1985. Effect of manual
defoliation on tomato yield and quality. Univ. Fla., IFAS, Agric. Exp.
Sta. Tech. Bull. No. 847. 41 pp.

7. McSorley, R., and K. Pohronezny. 1981. A simple bioassay as a
supplement to soil extraction for detection of root-knot nematodes. Proc.
Soil Crop Soc. Fla. 40:120-123.

8. McSorley, R., and K. Pohronezny. 1984. Cost-effectiveness of nematode
control by fumigation with SMDC on Rockdale soils. Proc. Soil and Crop
Sci Soc. Fla. 43:188-192.

9. McSorley, R., K Pohronezny, and W.M. Stall. 1981. Aspects of nematode
control on snap bean with emphasis on the relationship between nematode
density and plant damage. Proc. Fla. State Hort. Soc. 94:134-136.

10. Oatman, E. R., and G. C. Kennedy. 1976. Methomyl induced outbreak
of Liriomyza sativae on tomato. J. Econ. Entomol. 69:667-668.

11. Pohronezny, K., J. Francis, and W.G. Fong. 1987. Strategies for chemical
control of snap bean rust in Florida and their compatibility with Canadian
residue tolerances. Plant Dis. 71:639-642.

12. Pohronezny, K., and V. Waddill. 1986. Integrated pest management-
development of an alternative approach to control of tomato pests in
Florida. Univ. Fla., IFAS, Ext. Plant Pathol. Rep. No. 22 (revised). 7 pp.

13. Pohronezny, K., V. H. Waddill, D. J. Schuster, and R. M. Sonoda. 1986.
Integrated pest management for Florida tomatoes. Plant Dis. 70:96-102.








14. Pohronezny, K, V. H. Waddill, W. M. Stall, and W. Dankers. 1978.
Integrated control of the vegetable leafminer (Liromyza sativae Blanchard)
during the 1977-78 tomato season in Dade County, Florida. Proc. Fla.
State Hort. Soc. 91:264-267.

15. Schuster, D. J., R. T. Montgomery, D. L. Gibbs, G. A. Marolowe, J.P.
Jones, and A. J. Overman. 1980. The tomato pest management program
in Manatee and Hillsborough Counties, 1978-80. Proc. Fla. State Hort.
Soc. 93:235-237.

16. Sonoda, R. M., and K Pohronezny. 1983. Status and potential of
pesticide resistance among fungal and bacterial pathogens of vegetable
crops in Florida. Proc. Fla. State Hort. Soc. 96:66-69.

17. Stall, R. E., and P. L. Thayer. 1962. Streptomycin resistance of the
bacterial spot pathogen and control with streptomycin. Plant Dis. Rep.
46:389-392.

18. Stern, V. M., R. F. Smith, R. van der Bosch, and K S. Hagen. 1959.
The integrated control concept. Hilgardia 29:81-101.

19. Townsend, K G., and B. Abbitt. 1978. Four year summary of coopera-
tive extension service integrated pest management program. Proc. Fla.
State Hort Soc. 91:68-72.

20. Waddill, V. H., R. McSorley, and K Pohronezny. 1980. Field monitoring:
basis for integrated management of pests on snap beans. Trop. Agric.
58:157-169.

21. Waddill, V. H., and K. Pohronezny. 1979. Tomato IPM: key to vegetable
leafminer control. Citrus Veg. Mag. 42:34-37.

22. Zitter, T. A., and H. Y. Ozaki 1978. Aphid-borne vegetable viruses
controlled with oil sprays. Proc. Fla. State Hort. Soc. 91:287-289.









APPENDIX


IMPACT STUDY ON FLORIDA'S VEGETABLE IPM PROGRAM



Ken Pohronezny, Dave Schuster, Van Waddill,
Robert McSorley, and Jim Price

SECTION I.

QUESTIONS TO BE ASKED OF ALL GROWERS INTERVIEWED,
REGARDLESS OF COMMODITY.


1. How many acres of (tomatoes, strawberries, snap
beans, bell peppers) do you grow?

2. How many acres do you have scouted?


ANS.

ANS.


IF NONE OF YOUR ACREAGE IS SCOUTED, SKIP TO NO. 9.
3. If you have acreage scouted, who does the scouting?
[Possible answers include:]


A) Commercial scouts?


ANS.


B) "In-house", full-time scouts?

C) Grower himself?

E) Chemical reps?

4. If your fields are scouted, which of the follow-
ing pest categories are included in the scouting
report? (check any or all).
A)_ insects
B)_ diseases
C)_ nematodes
D)_ weeds

5. In describing my control program, I would say my
insect control decisions are based on scouting
reports (check one).
A)__ (0%)
B)_ seldom (1-33% of the time)
C)__ often (34-67% of the time)
D)_ in most cases (67-99% of the time)
E)_ (100%)









6. In describing my control program, I would say my disease
control decisions are based on scouting
reports (check one).
A)__ (0%)
B) seldom (1-33% of the time)
C)_ often (34-67% of the time)
D)_ in most cases (67-99% of the time)
E)_ (100%)

7. In describing my control program, I would say my
preplant nematode control decisions are based on
scouting reports (check one).
A)_ (0%)
B)_ seldom (1-33% of the time)
C)__ often (34-67% of the time)
D)__ in most cases (67-99% of the time)
E)__ (100%)

8. In describing my control program, I would say my
weed control decisions are based on scouting
reports.
A)__ (0%)
B)___ seldom (1-33% of the time)
C)__ often (34-67% of the time)
D)__ in most cases (67-99% of the time)
E)__ (100%)

9. Please rank the following 5 possible benefits of
IPM as you perceive them in your farming opera-
tions from highest to lowest priority (1-highest
priority; 5-lowest priority).
A)__ extended useful lifetime of
pesticides
B)__ increased net returns
C) reduced environmental pollution
D)__ improved levels of pest control
E)_ early detection and accurate
identification of pests

10. Do you feel that in your IPM program (check one)
A) costs of scouting (assessed fees)
about equal reduced production
costs
B)_ expenses are increased
C)__ net returns are increased (through
reduced expenses)









10. Which of the following practices do you use in
attempting to minimize damage from bacterial spot
and other bacterial diseases (check all that apply)?
A)__ treat seed with dilute commercial
bleach or other hypochlorite treat-
ment
B)__ avoid handling of wet plants
C)__ destroy summer volunteer tomato plants
D)__ spray with copper and maneb (mancozeb)
E)_ spray with copper and maneb or mancozeb
(or other fungicide alone) depending
on weather conditions and scouting
reports.

11. Over the last several seasons, what would you say your two
most important insect pests have been?

12. Over the last several seasons, what would you say your two
most important disease problems have been?



13. Over the last several seasons, what would you say your two
most important nematode problems have been?

14. Over the last several seasons, what would you say your two
most important weed problems have been?









SECTION III.


SPECIFIC QUESTIONS FOR SNAP BEAN GROWERS

1. Is your nematode control program based on (select
one)?
A)_ preplant fumigation in all cases
B)_ treatment decisions based on preplant
counts
C)__ treatment decisions made relative to
to populations detected during crop growth
D)__ treatment decisions based on condition
of previous crop
E)__ no control program

2. Are you using bioassay plants for prepant assess-
ment of root knot nematodes? ANS.

3. What level of defoliation (%) prebloom and post-
bloom do you think a snap bean plant can tolerate
without any loss in yield or quality? ANS.

4. Do you use defoliation thresholds in your decision-
making for pest control? ANS.

5. For your operation, rank in order of importance
these factors in controlling bacterial diseases of
bean (especially common bacterial blight) (1-highest
priority; 4-lowest priority).
A)___ use of disease-free seed
B)__ foliar applications of copper compounds
C) avoidance of movement of personnel
and equipment in fields when plants are
wet
D)_ resistant varieties

6. Do you consider nematode control more important in
the fall crop or the spring crop? ANS.

7. Do you use chloroneb ("Demosan") as a partial
control of Rhizoctonia disease? ANS.
If so, do you apply it as a hopper-box treatment
or as an in-furrow spray? ANS.

8. All things being even over the seasons, in what month
do you begin spraying benomyl (or other specific
fungicides) for Sclerotinia (white mold) control? ANS.









9. Indicate the number which is nearest to your
current predominant spacing between rows of the
snap bean crop.
A)__ 36 in.
B)__ 30 in.
C)__ 24 in.
D)_ 18 in.

10. Indicate the number which is closest to your current
predominant spacing between plants in a row of beans.
A)__ 1 in.
B)__ 2 in.
C)__ 3 in.
D)_ 4 in.

11. Check below the choice that best describes your approach
to chemical control of bean rust.
A)__ maneb until the preharvest limit
B)__ maneb and sulfur until the preharvest
limit
C)__ chlorothalonil until the preharvest
limit
D)_ maneb or maneb and sulfur until
flowering, followed by chlorothalonil
E)_ other regimen (please specify)

12. Do you consider parasites and predators (beneficial
insects) in making control decisions for leaf-
miner? ANS.

13. Over the last several seasons, what would you say your two
most important insect pests have been?

14. Over the last several seasons, what would you say your two
most important disease problems have been?

15. Over the last several seasons, what would you say your two
most important nematode problems have been?

16. Over the last several seasons, what would you say your two
most important weed problems have been?









SECTION IV.


SPECIFIC QUESTIONS FOR STRAWBERRY GROWERS

1. Are the strawberry plants you use inspected for one
or more pests prior to shipment to your farm? ANS.
2. How important are the following factors in your
selection of a crop site (circle one answer for
each part).
A) previous crop type not at all little moderate higl
B) neighboring crop type not at all little moderate higl
C) availability of land not at all little moderate higl
3. Do you adjust pest control expenditures during
the season as expected prices of the crop change
(check one)?
A)__ (0%)
B)__ seldom (1-33% of the time)
C)_ often (34-67% of the time)
D)__ in most cases (67-99% of the time)
E)__ (100%)
4. To what extent do you feel that pest problems in your
neighbors' fields affect your own pest problems
(check one)?
A)__ no effect
B)__ little effect
C)_ moderate effect
D)_ great effect
5. Rank the following attributes of a cultivar as to
their importance in selecting the cultivar to be
transplanted in your field (1-highest priority;
6-lowest priority).
A)__ earliness
B)_ anthracnose resistance
C)__ fruit size
D)___ taste
E)__ brokers' market preference
F)__ yield
6. Do you currently use releases of beneficial
predatory mites for spider mite control? ANS.
7. If a beneficial predator of spider mites were
available at a reasonable cost, would you consider
using the predator in lieu of chemical miticides? ANS.









8. Is your nematode control program based on (select
one)?
A)_ preplant fumigation in all cases
B)__ treatment decisions based on preplant
counts
C)__ treatment decisions made relative to
to populations detected during crop growth
D)_ treatment decisions based on condition
of previous crop
E)__ no control program

9. What fungicide do you depend most on for control of
the dominant strawberry foliar diseases (e.g. common
leaf spot, scorch)? ANS.

10. Over the last several seasons, what would you say your two
most important insect pests have been?

11. Over the last several seasons, what would you say your two
most important disease problems have been?



12. Over the last several seasons, what would you say your two
most important nematode problems have been?



13. Over the last several seasons, what would you say your two
most important weed problems have been?









SECTION V.


SPECIFIC QUESTIONS FOR PEPPER GROWERS

1. Which of the following cultural practices do you
follow in attempting to control pepper weevil? (check
one or all that apply).
A)__ prompt destruction of crop after
last picking
B)___ destruction of culls
C)_ maintaining minimum level of control
during U-Pick
D)_ control of in-field and field border
infestations of nightshade

2. Do you use streptomycin as part of your spray
program for control of bacterial spot? ANS.
If so, about how many applications per crop do
you make? ANS.

3. Rank in order of importance the following factors
in the selection of a pepper variety (l=highest
priority; 5-lowest priority).
A)__ concentrated fruit set
B)__ fruit shape and size
C)__ virus resistance
D)__ earliness
E)__ yield

4. Which of the following practices do you use in
attempting to minimize damage from bacterial spot
and other bacterial diseases (check all that apply)?
A)__ treat seed with dilute commercial
bleach or other hypochlorite treat-
ment
B)__ avoid handling of wet plants
C)__ destroy summer volunteer pepper plants
D)__ spray with copper and maneb or mancozeb
E)_ spray with copper and maneb or mancozeb
(or other fungicide alone) depending
on weather conditions and scouting
reports.









5. My ne
(chec


matode
k one)


control program is best described as


A)__ fumigation prior to planting the peppers
B)_ application of nematicides to growing
plants
C)__ depends on fumigation of previous crop
for adequate control
D)_ depends on fumigation of previous crop
and application of nematicides to
growing plants
E)__ no control is used


6. My nematode control decisions are ( check any that apply).
A)__ based on samples taken prior to planting
B)__ based on samples taken during plant
growth
C)__ based on samples taken in the previous crop
D)__ not based on samples and scouting

7. Over the last several seasons, what would you say your two
most important insect pests have been?

8. Over the last several seasons, what would you say your two
most important disease problems have been?

9. Over the last several seasons, what would you say your two
most important nematode problems have been?

10. Over the last several seasons, what would you say your two
most important weed problems have been?









SECTION V.


SPECIFIC QUESTIONS FOR PEPPER GROWERS


1. Which of the following cultural practices do you
follow in attempting to control pepper weevil? (check
one or all that apply).
A)__ prompt destruction of crop after
last picking
B)__ destruction of culls
C)__ maintaining minimum level of control
during U-Pick
D)_ control of in-field and field border
infestations of nightshade


2. Do you use streptomycin as part of your spray
program for control of bacterial spot? ANS.
If so, about how many applications per crop do
you make? ANS.

3. Rank in order of importance the following factors
in the selection of a pepper variety (1-highest
priority; 5=lowest priority).
A)___ concentrated fruit set
B)__ fruit shape and size
C)__ virus resistance
D)__ earliness
E)__ yield

4. Which of the following practices do you use in
attempting to minimize damage from bacterial spot
and other bacterial diseases (check all that apply)?
A)__ treat seed with dilute commercial
bleach or other hypochlorite treat-
ment
B)__ avoid handling of wet plants
C)_ destroy summer volunteer pepper plants
D)__ spray with copper and maneb or mancozeb
E)_ spray with copper and maneb or mancozeb
(or other fungicide alone) depending
on weather conditions and scouting
reports.








5. My nematode control program is best described as
(check one)
A)__ fumigation prior to planting the peppers
B)__ application of nematicides to growing
plants
C)_ depends on fumigation of previous crop
for adequate control
D)_ depends on fumigation of previous crop
and application of nematicides to
growing plants
E)__ no control is used

6. My nematode control decisions are ( check any that apply).
A)__ based on samples taken prior to planting
B)__ based on samples taken during plant
growth
C)__ based on samples taken in the previous crop
D)__ not based on samples and scouting

7. Over the last several seasons, what would you say your two
most important insect pests have been? _

8. Over the last several seasons, what would you say your two
most important disease problems have been?

9. Over the last several seasons, what would you say your two
most important nematode problems have been?

10. Over the last several seasons, what would you say your two
most important weed problems have been?






































UNIVERSITY OF FLORIDA


This publication was promulgated at a cost of $3,637.00, or
$1.45 a copy, to inform Floridians about the impact of inte-
grated pest management on selected vegetable crops in Florida.



All programs and related activities sponsored or assisted by the Florida
Agricultural Experiment Station are open to all persons regardless of race,
color, national origin, age, sex, or handicap.


ISSN 0096-6071




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs