Greenhouse IPM for the Amish and Mennonite community of Lancaster County

Final Report for LNE03-176

Project Type: Research and Education
Funds awarded in 2003: $56,890.00
Projected End Date: 12/31/2006
Matching Non-Federal Funds: $6,700.00
Region: Northeast
State: Pennsylvania
Project Leader:
David Bingaman
Pennsylvania Department of Agriculture
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Project Information


Lancaster County, Pennsylvania is the top non-irrigated, agricultural county in the United States and has one of the largest concentrations of Amish and Mennonite farmers in the country. These communities have traditionally been made up of dairy and tobacco farmers. In recent years however, low dairy and tobacco prices have caused many farmers to turn to high value crops including greenhouse vegetables, herbs, and flowers to supplement their income. Greenhouses are a means for local producers to extend the growing season and improve yields and quality of vegetable and flower crops, thus gaining additional income for their farming operations.
Amish and Mennonite greenhouse operations often involve the whole family, with all family members participating in the production process. The intensive use of pesticides in greenhouses and children, which are commonly barefoot, working with their parents in pesticide application areas have become a growing concern.

Education and training on the use of Integrated Pest Management (IPM) and biological controls (biocontrols) in greenhouse production has been lacking among the Amish and conservative Mennonites in Lancaster County, Pennsylvania. Given that members of Amish and Mennonite community travel by horse and buggy, their ability to attend educational meetings is limited. Traditional broad-based educational presentations using slides, overheads, videos or PowerPoint are often forbidden by many sects of the Amish community as well.

Through the use of seminars and on-farm weekly one-on-one training of individual greenhouse growers with an IPM/biocontrol specialist, growers learned pest identification, pest life cycles, and proper control of those pests using IPM and biocontrol techniques. The use of proper crop scouting and record keeping; sanitation; cultural, mechanical, and biological controls; and reduced-risk pesticides was also taught. Due to the weekly farm visits by the IPM/biocontrol specialist throughout a cropping cycle, growers developed a good working relationship and trust in not only the specialist, but also in the recommendations that the specialist made. This relationship and prolonged educational experience initiated a life-long adaptation of IPM and biocontrol methods by all growers involved in the program.

New techniques and changed attitudes resulting from a one-on-one approach created immediate positive changes in pesticide usage. This hands-on educational program lead to a decrease in conventional pesticide usage (particularly high risk pesticides) of at least 50 percent as growers learned a whole system approach to pest management. The implementation of IPM and biocontrol techniques in the greenhouse also lead to: an increase in crop quality and yield; an increase in the profitability and sustainability of local greenhouse operations; and a safer working environment for growers and their families (especially children). This program resulted in transferable technology that can be used in greenhouses throughout the United States.

Performance Target:

Have 30 greenhouse growers reduce traditional pesticide use by at least 50 percent replacing them with IPM techniques.

Over the three years of the project we worked with 33 greenhouse growers (23 flower greenhouses, 10 vegetable and herb greenhouses), educating them in the proper use of IPM and biocontrol techniques. All of the 33 greenhouse growers adopted varying IPM and biocontrol techniques into their pest management program, leading to a reduction in their use of traditional pesticides by an average of 50%. Several growers reduced pesticide usage to near zero as they fully implemented a complete biocontrol program.


Click linked name(s) to expand/collapse or show everyone's info
  • Wade Esbenshade
  • Jeff Stoltzfus
  • Cathy Thomas


Materials and methods:

In the first year, a group of ten vegetable, herb and flower growers were selected to initiate the hands-on approach to learn the IPM/biocontrol program. The mind-set of the grower was very important in the selection stage of the project. Only growers who demonstrated a positive attitude and strong desire to change the way they were managing their pests were selected to participate. For the system to work, a grower must have the patience necessary to work with the system.

Cathy Thomas, a recognized expert in greenhouse IPM/biocontrol systems with more than twenty years experience in the field, worked to oversee the technical aspects of the project. Cathy was also responsible for the training of a local IPM/biocontrol Specialist from Penn State University, Wade Esbenshade. Through his contact with the Amish and Mennonite community, Jeff Stoltzfus, Adult Farmer Program Advisor for the Eastern Lancaster County School District, provided Cathy, with a list of potential cooperators who expressed their strong interest and desire to change their current conventional production practices to ones based on IPM and biocontrol methods. Cathy then met with the potential cooperators to explain the program, interview the growers, and select growers who were committed to making long-term changes in their pest control and production practices.

IPM/biocontrol is a combination of management techniques requiring training over an extended period of time. After an initial orientation meeting, the growers and the IPM/biocontrol specialist worked together on a weekly basis throughout the crop production cycle. During the weekly visits, the specialist would walk through the participating greenhouses with growers, teaching them scouting techniques and helping them to identify pest problems. Through this interactive learning process, growers rapidly learned proper pest scouting techniques, pest identification, and the life cycles of pests.

Training also included biocontrol alternatives that could be blended with compatible chemical controls to manage the pest complex. Growers learned pest and biocontrol life cycles, the proper release of biocontrols, population assessment of both parasitized and non-parasitized pests, and how to determine pest thresholds. When necessary, the program allowed growers to identify pest problems and develop a practical control strategy within the production constraints of their own greenhouse. The specialist guided growers through a crop cycle to gain confidence and independence. These new pest control methods created a natural pest management system allowing growers to reduce or replace the use of traditional pesticides.

At the end of the first year, ten greenhouse operators implemented an IPM/biocontrol program. Two new groups of growers participated in the program the following two years. During this time, Cathy and Wade were able to continue to provide expertise and advice to the previous group of growers on IPM and biocontrols as they trained a new group. Over the three year life span of the project, a total of thirty-three growers were able to implement the IPM/biocontrols system.

In addition to the on-farm one-on-one training, an all-day IPM/biocontrol workshop was held at Black Creek Greenhouse in East Earl, Lancaster County. Pest management specialist from Penn State University, PA Department of Agriculture, and the biocontrol industry gave presentations on a variety of greenhouse pest control topics. The more than 40 local greenhouse growers who attended the all day workshop also had opportunity to receive hands-on training on insect and biological control identification. Due to workshops such as this one, growers can further increase their knowledge and improve their own pest management techniques. The workshop was also used to increase the awareness of the IPM/biocontrol program.

Research results and discussion:
Results, Milestones, and Outcomes

Weekly visits of the participating greenhouse growers by Wade Esbenshade began in late January and continued through early June of each year. During these visits, growers learned various IPM techniques including: insect identification on sticky cards; record keeping on pest levels and thresholds; plant inspection for insect damage and disease development; proper use of natural enemies; and proper use of reduced-risk pesticides, such as insect growth regulators, soaps, oils, and target-specific insecticides. Growers were also given a new greenhouse manual, “Greenhouse IPM with an Emphasis on Biocontrol” by Cathy Thomas, along with other information for study and reference on developing an IPM program in their operations and implementing biological controls to replace the use of traditional pesticides.

Half of the growers used biological controls, such as beneficial nematodes (Steinernema feltiae), to replace soil applications of insecticides to control fungus gnat larvae, a very destructive greenhouse pest. Four growers also introduced parasitoid wasps and predatory mites to control pests such as aphids, whiteflies, and two-spotted spider mites, almost completely eliminating pesticides. Biological fungicides were used by nearly three quarters of growers to control root diseases such as pythium, and rhizoctonia, as well as several foliar diseases. The use of these natural products was able to replace and/or reduce the use of traditional chemical fungicides. Growers felt that overall control of pests was better compared to previous crop cycles and losses due to pathogens had decreased significantly.

One limitation to the further use and implementation of biocontrols in the participating greenhouses is the current expense of biocontrols. Although most growers showed a strong desire to eliminate chemical pesticides in their operations, many were reluctant to pay the higher price of the biocontrols needed. Growers who did use biocontrols to manage their pest problems were very satisfied with the results. However, most growers are working with a limited amount of financial resources and therefore were reluctant to pay the increased expense. Hopefully as more U.S. growers make the shift towards biocontrols, pricing will become more competitive with the ever-increasing expense of chemical pesticides.

In general, growers were very open and receptive to the information and pest control techniques that were being taught by the IPM/biocontrol specialist. Due to the weekly farm visits throughout the growing season, growers quickly developed a personal working relationship with the specialist and gained confidence in the information and recommendations that were being provided. The weekly visits also forced growers to take time out of their busy schedules and devote it to crop scouting and controlling pests.

Growers reported numerous benefits to the program and the new techniques that they acquired. All growers felt as if they increased the quality of their crops due to locating problems early and controlling them effectively with the IPM/biocontrol methods that were being learned.

Using control tactics after scouting and only when necessary as well as controlling pest problems at low levels resulted in a significant reduction in pesticide use and overall control costs. Growers commented on having a safer working environment for themselves, their families, and their employees due to the reduction in pesticide usage. They enjoyed being able to have quicker access to the greenhouse due to no re-entry interval restrictions when using biological control methods and shorter REI’s when using reduced risk compounds. Adoption of the IPM/biocontrol system also allowed the use of bumble bees for pollination of vegetable crops which improved production, fruit quality, and decreased the amount of labor needed to pollinate crops.

Unlike traditional pesticide education methods, this educational approach guaranteed immediate implementation of IPM/biocontrol methods. Long-term adaptation of the techniques and methods that were being learned is great due to a behavior change by growers. Due to growers being required to change their behavior and set aside time each week for to focus on pest control for an entire growing season, growers are more likely to continue the practice in the future. Follow-up visits to growers who have successfully completed the program have shown that growers are implementing approximately 90% of the information and habits that they previously acquired.

Participation Summary


Educational approach:

The manual, "Greenhouse IPM with an Emphasis on Biocontrol", was developed by Cathy Thomas in response to the need for practical information on greenhouse IPM and biocontrols. Based on Thomas' "Bug vs. Bug" article series, the 108-page manual begins with an introduction to IPM and its principles, information on starting an IPM/biocontrol program and using compatible pesticides, and addresses many of the most common greenhouse pests and their biocontrols. In addition, the manual contains more than 90 full-color images as well as descriptions of the most common pests in the greenhouse industry and the biocontrols used to manage them. The manual is very practical and designed to instruct greenhouse operators through a stepwise process of pest control.

No milestones
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.