Community Education - IPM - UMass Extension

Tina M. Smith Extension Educator Plant & Soil Sciences	William M. Coli Extension Educator Entomology
Margaret Christie Survey Coordinator	Bert Szala Extension Technician

Introduction
This summary presents results of a survey of spring bedding plant growers in five New England states conducted by UMass Extension during 1996. The survey was part of a larger project that surveyed commercial growers of apples, sweet corn, potatoes and strawberries throughout the Northeast. The goals of the project were to define current IPM systems that are ready for adoption, to determine the extent of actual adoption, and to prioritize IPM research and outreach needs. The entire project was funded by a USDA National IPM Initiative Phase I IPM planning grant, and by the UMass Agriculture and Landscape Integrated Pest Management Program and UMass Extension.

Who was surveyed
The target population for the survey consisted of bedding plant growers from Massachusetts, Connecticut, Vermont, New Hampshire and Maine. The list of businesses to be surveyed was developed from mailing lists from grower associations and University Extension programs. Of the 906 surveys mailed throughout New England, 537 were returned. Thirty-four percent of respondents indicated that they grew bedding plants and results of these surveys are presented here.

A mail questionnaire was selected as the most appropriate vehicle to gather information because of the number of questions and the amount of information needed to be gathered in this study. Content of the questions was based on input and review from growers, Extension staff and faculty located in the five participating states, with UMass serving as lead unit and overall project coordinator. The survey was divided into sections addressing cultural practices, pesticide application and record-keeping, general pest management, insect management, weed management, disease management and effects of IPM

The nature of the New England bedding plant industry
According to the 1995 New England Agricultural Statistics(NASS), the greenhouse/nursery industry accounted for 19% of cash receipts from agriculture, ranking this industry second after dairy. Bedding plant sales in Massachusetts alone were valued at $26.7 million wholesale, making Massachusetts the top producing bedding plant state in New England. The greenhouse industry on the whole is a diverse and multi-faceted group of businesses with a long history of agricultural production.

The majority of respondents indicated that they have been in operation an average of 25 years. The majority of plants grown in greenhouses in New England are bedding plants and for many businesses, these crops contribute significantly to their income. The average responding grower earns 61% of income from bedding plants, with 70% of sales retail and 30% wholesale.

Leaving a greenhouse fallow
The first question in this section asked, "Do you leave any of your growing space empty or "fallow" during the year? Of the 293 respondents to this question, 81.% answered yes. The high number of respondents that answered yes reflects the fact that bedding plants are a seasonal crop requiring additional greenhouse space in the spring that would be used only for that crop. The fact that these businesses have greenhouses that are left fallow is an opportunity to reduce pest populations. Compared to a seasonal greenhouse, one in use year round has a greater risk that pests may be carried over from one crop cycle to another.

"Pet plants"
Growers were split in their responses to the question asking if "pet plants" were removed from inside and outside the greenhouse at least one month before introducing the crop. Forty percent said that they always removed pet plants, 35% did so sometimes and 26% never did. Pet plants are those that are not being grown for a commercial purpose but are in greenhouses with commercial crops. They may be a customer's plant being nursed back to health, or a plant growing in a corner of the greenhouse that is special to an employee or owner. Such plants can serve as a reservoir for insect pests and diseases and it is recommended that they be removed prior to introducing a crop into the greenhouse.

Nutrient management
Nutrient management is an important component of integrated crop production and it plays a major role in plant health and overall crop quality. Growers were asked how often they calibrated their fertilizer injector during an average spring production cycle and were given the opportunity to reply never, once, or more than once. More than half of the growers (62%) calibrate their fertilizer injector at least once during the spring. Thirty eight percent of respondents never calibrate their injector, 36% do so once and 26% more than once each year.

Growers were less likely to have their soil tested during an average spring production cycle (64% never, 24% once, 9% 2-4 times and 2% more than 4 times). Only 21% of the growers adjust their fertilizer rate based on soil test results. Other respondents adjust their fertilizer rate based on plant appearance and experience. One grower stated that the rate used is based on a "seat of pants" estimate.

Fifty-six percent of growers use controlled release fertilizers. High soluble salts, nutrient toxicity and nutrient deficiencies are all common problems during the spring bedding plant season. From these responses, it is evident that more emphasis should be placed on the value of soil tests and injector calibration in extension meetings .

The final question in this section asked about the type of irrigation currently in use. Drip irrigation (44%) and hand-watering (23%) were the two methods used most often by growers. Fourteen percent use saucers to water the crop. Ebb and flood systems, overhead sprinklers and booms and trough systems are used by 8%, 7% and 6% of growers respectively. Many growers likely still hand water plants for a variety of reasons: they use the time when watering to observe plants and spot any problem areas, this method is very adaptable to any pot size, and there is very little initial investment. However, hand-watering is very labor intensive and wasteful. Subirrigation, including ebb and flood, trough, saucers and mats saves labor, fertilizer and water. Though very efficient for bedding plant production, most Subirrigation systems are expensive to install and some are not adaptable to different sized containers used for bedding plants. Lower initial costs would motivate some growers to adopt Subirrigation systems. Drip irrigation and saucers are used for potted plants and hanging baskets and are very efficient methods of irrigation. More emphasis should be placed on maximizing watering efficiency during extension training sessions or by additional demonstrations in grower greenhouses

Tank-mixing pesticides
Half of the growers (50%) responded that they never mixed 2 or more pesticides together, while 46% circled that they sometimes did. Only 5% circled that they always tank mixed pesticides. Although research has shown that tank mixing pesticides can increase the incidence of pest resistance to insecticides, for some pests such as thrips, tank mixing has proven to be more effective than using pesticides separately.

Rotating classes of pesticides
It is well documented that rotating to a different class of pesticide after one to two generations of insects (for example, changing from organophosphates to pyrethroids) is helpful in reducing the incidence of pest resistance to insecticides. According to survey responses, the majority (82%) of growers rotate classes of pesticides. Forty three percent of growers responded that they sometimes rotate classes of pesticides after one or two insect generations and 39% responded that they always do. Although only 18% of all growers claim to never rotate classes of pesticide, there was substantial variation among states in response to this choice (from a low of 8% in one state to a high of 32% in another). Desirability of this practice would indicate an opportunity for enhanced grower education in that state.

Number of treatments for specific pests
Growers were asked to estimate the number of pesticide treatments they applied to a specific list of insect pests and diseases. The greatest average number of sprays were applied to control thrips (average of 3.6 sprays), with aphids close behind (average of 3.5 sprays). The least number of sprays were applied to control shoreflies (average of 1.95 sprays). Thrips and the Impatiens Necrotic Spot Virus (INSV) they spread have been a major problem in the bedding plant industry in recent years. Research and educational programs focusing on thrips and INSV continue to be needed.

On average, slightly more treatments were used to control Botrytis (1.9) than root rots (1.3). Both diseases cause problems on a wide variety of bedding plants. Most growers tend to use a preventative treatment for root rots while they may wait for symptoms to show before treating for Botrytis. This may account for the higher number of sprays applied for Botrytis compared to root rot.

It is interesting to note the trend regarding pesticide use according to size of greenhouse operation in the following table.

Although sprays against aphids, whiteflies and spider mites show no obvious pattern in relation to size, there is a clear trend toward increasing numbers of sprays for thrips, fungus gnats, shoreflies, root rots and botrytis as greenhouse operation size increases.

How to know when to treat
One hundred forty growers (50%) responded that the most frequently used method to base the timing of their pesticide application was results of a scouting program. The next most frequent method was informal observation (33%). Only 9% based their pesticide application on a time schedule. This shows that many growers are using the very basis of IPM, scouting, as a method to detect the presence of pests and time their pesticide applications. In Massachusetts, the Extension Floriculture Program began its IPM program in 1990 focusing on teaching growers to scout. Each year since then, scouting has been emphasized as part of growers outreach.

Choosing pesticides
Eighty six percent of growers replied that the pesticide effectiveness (from previous experience) was very important in choosing a pesticide, 68% considered potential toxicity to greenhouse workers as very important, and 58% ranked re-entry time the same. Although pesticide effectiveness appeared to be the most important criterion in pesticide choice, toxicity is also very important to growers, likely because of their concern for worker safety. The recent enactment of Federal Worker Protection Standard (WPS) regulations specifying the length of time workers must wait before re-entering a greenhouse after a pesticide application undoubtedly has influenced the way growers choose pesticides.

Not surprisingly, slightly over 67% of growers reported that cost was somewhat to very important in their choice of a pesticide.

Calibrating sprayers and using indicator plants
According to survey results, while thirty four percent of the growers replace worn nozzles on application equipment, only 27% maintain and calibrate their sprayers for rate at least once during the bedding plant season, only 9% calibrate equipment for droplet size, and 4% use water/oil sensitive cards during calibration to test sprayer coverage of leaf surface. Although growers may walk through the greenhouse after treatment and make general observations, only about 25% mark a small number of infested plants and observe them over time to evaluate the effectiveness of their pesticide treatments. Marking indicator plants is the recommended method to monitor effectiveness of pesticide treatments over time, since insect growth regulators or systemic pesticides may take several days or weeks to affect population levels. It may also take time to see results of fungicide applications for diseases such as powdery mildew. Growers often report that particular pesticides are ineffective or that a particular insect is difficult to control. However, such reports may actually be due to inadequate spray equipment, sprayer calibration or evaluation of the treated area. It appears from these responses that more outreach education in this area would be important.

Types of pesticide application used
Probably because of their versatility, hydraulic sprayers are the most frequently used type of pesticide application equipment (47%), followed by aerosol bombs (41%), granules (26%), smoke generators (18%), mist blowers (14%), and foggers (15%). Only 9% of the respondents to this question use electrostatic sprayers. Aerosol bombs, though more expensive than some other methods, are easy to use, especially for small growers and do not require special equipment. Applying granules to the soil is another easy method of applying a pesticide. The response to this question possibly reflects the wide-spread use of granular Marathon, an effective, general use pesticide for whitefly control which is widely used by growers.

Record-keeping
Seventy-six percent of growers surveyed report that they maintain pesticide records. The principal reason given for doing so is that it is required by the states (88%). Growers also maintain pesticide records to help them to make pest management decisions on their current crops (62%) and to assist in management decisions the following year (55%).

Alternatives to conventional pesticides
Growers were asked to check off from a list, specific materials that they used. Two hundred eighty seven responded to this question. Of the materials listed, 53% of the growers used insecticidal soaps, 35% used insect growth regulators, 24% used horticultural oils, 12% used beneficial nematodes and 14% used other biological control agents. Although conventional pesticides are still widely used by growers, there is an encouraging trend toward use of biological materials, and products that are environmentally friendly and safe for applicators. The wide-use of these products supports evidence that growers are genuinely concerned about the toxicity of the pesticides.

Scouting
Ninety percent (217) of growers indicated that they were the ones who scouted their greenhouses. Only 3% (6) used a hired employee and 2 growers (0.8%) hired an independent crop consultant. This is not unusual since most greenhouse businesses in New England are small family run businesses who have traditionally managed their own pest problems. Also, there are very few private scouts available in New England for growers to hire. Extension training of additional private-sector scouts, and potential provision of business start up funds may increase use of formal scouting programs, especially because 20% of survey respondents list "cost-sharing of IPM consultants" as an encouragement to use IPM techniques they are not currently using in a later question.

The monitoring techniques used most often are weekly examination of randomly-selected plants (67%) and yellow sticky cards (63%). Forty percent of growers use an optivisor, hand lens or microscope to assist their monitoring. Although a significant number of growers are using the two monitoring techniques which form the basis of a greenhouse IPM system, about 8% use none of the monitoring techniques listed. About 10% of the growers used indicator plants such as petunias or fava bean to detect Impatiens Necrotic Spot Virus (INSV) and 5% used potato plugs to monitor fungus gnat larvae. Since a previous question indicated that thrips are an important pest, the use of indicator plants to detect INSV would seem to be a valuable tool for growers.

While most maintain pesticide use records, many (83%) do not maintain records of pest monitoring. Of the 17% (n= 45) of the growers that maintained pest records, monitoring the effectiveness of a treatment and helping decide if a treatment was needed were equally important reasons for doing so. Maintaining records is time-consuming for growers. However, pest monitoring records can provide growers with information about pest population trends that can indicate the effectiveness of pesticide treatments and other management practices. The importance of maintaining scouting information should be emphasized in extension training.

Most growers (84%) said that they inspect incoming plants and/or cuttings immediately upon arrival for insects, diseases and other problems. Twenty five percent isolate incoming plants until visual inspection can be made and 22% use sticky cards to monitor for insects on incoming plant material. Only 2% request pesticide use information from suppliers of incoming plants. This low response is not surprising since the floriculture industry is global, and plant material is shipped throughout the United States and the world. Since many purchases of plant material are through a broker, one item may come from one grower in one state and another from a different grower in a different state. Obviously, it would be very difficult and time-consuming to track down pesticides used on purchased plants.

Screening
Only 21 growers of 296 (7.1%) have installed screening to prevent insects from entering the greenhouses. This is likely due to the fact that screening is expensive to retrofit to existing greenhouses and has to be properly installed for adequate ventilation. Thus, the practice may not currently be practical for small bedding plant growers. However, it would be valuable for a wholesale propagator, or producer of plants that are susceptible to the thrips/INSV complex.

Weed management
Weeds are a source of insect and disease problems in greenhouses and weed management is an important part of IPM. Greenhouse pests will establish themselves on weeds outside the greenhouse during warm months and migrate from outside back to crops inside the greenhouse. Most growers (77%) eliminate weeds inside the greenhouse before a crop is introduced and 58% use mechanical weed management (e.g., fiber cloth). Forty three percent use herbicides inside the greenhouse and 42% use herbicides outside the greenhouse. However, only 20% eliminate grassed areas and weeds within 10-20 foot buffer zone outside the greenhouse.

Disease management
Eighty-six percent of respondents said that they observed bedding plants each week for symptoms of disease. Of the 287 growers that responded to this question, only 3 (1.15) used Agdia test kits on-site to detect diseases such as INSV. INSV test kits have a shelf life of about 1 year, and may be too expensive for small growers. However, their use would be beneficial to growers with a history of thrips and INSV and should be encouraged.

Horizontal air flow (HAF) is the practice of using strategically placed fans in the greenhouse to reduce the incidence of disease such as Botrytis and help maintain uniform temperature for better crop production. Over half (52%) of the growers have HAF in all their greenhouses and another 30% in some of their greenhouses. Only 18% do not use HAF.

Most growers (76%) said they always or sometimes sanitize greenhouse floors, benches and greenhouse structures. Twenty four percent responded that they never use this practice. Sanitizers eliminate algae which can reduce the incidence of fungus gnats and shoreflies in the greenhouse. Several commercial products are commonly used for this purpose in addition to household bleach.

Where growers obtain information
The next section of the survey asked how important are various sources of information about bedding plant pest and crop management. Growers reported that other growers are somewhat (46%) and very (43%) important, Extension specialists are very (45%), and somewhat (38%) important, Extension newsletters are somewhat (45%) and very (35%) important, trade magazines are somewhat (55%) and very (31%) important. Because there are very few private crop consultants in the New England region for greenhouse bedding plants 85% rated this information source as not important.. The importance of salespeople was split between 32% not, 50% somewhat and 18% very important. The importance of the New England Recommendation Guide was also split between 42% not, 27% somewhat and 31% very important. This response could be the result of growers not having a copy of this publication which is distributed primarily at the New England Greenhouse Conference every two years.

Growers experiences and opinions of IPM
A series of questions were asked about grower's experiences and opinions of IPM. Fifty five percent of growers disagreed with the statement that the use of IPM attracts more customers. Most growers (67%) agreed that the use of IPM increases management time. Most growers (88%) disagreed with the statement, "IPM allows growers to charge a higher price for their product". Most (62%) agreed that the use of IPM does not increase the costs of pest management. A sizable majority (63%) agree that use of IPM improves relations with neighbors. Most (92%) do not feel the use of IPM decreases the quality of the product, and they agree with the statement that the use of IPM leads to decreased insecticide use (91%).

What keeps growers from using an IPM technique? Fifty five percent said that they are satisfied with their current production methods. Thirty-four percent aren't sure about how effective the technique will be and 33% don't know exactly how to use it.

Over half of the growers (57%) said that they might be encouraged to adopt IPM techniques that they are currently not using if they learned more about how to use IPM techniques, they had better evidence that IPM techniques work (44%), they had new IPM techniques that are safer to the applicator than their current practices (42%), or if currently registered materials were no longer available (35%). A relatively small percent (20%) might adopt IPM if markets wanted IPM-grown crops or they had cost sharing for IPM consulting available to them (19%).

Acknowledgments
Support for this work came from the USDA North East Region National IPM Implementation Program, UMass Agriculture and Landscape Integrated Pest Management Program and University of Massachusetts Extension. The authors extend specific thanks to participants Paul Lopes and Roy VanDriesche, University of Massachusetts; Peter Konjoian, Konjoian's Greenhouse Inc., Massachusetts; Bob Demers, Demers Garden Center Inc., New Hampshire; Jay Wilson, Newfane Greenhouses, Vermont; and John Hinman, Connecticut who contributed to the bedding plant survey design. The following Faculty and Staff contributed to the bedding plant survey design and also represented their state University in the mailing of the survey; Margaret Skinner and Michael Brownbridge, University of Vermont; Alan Eaton, University of New Hampshire; Leanne Pundt, University of Connecticut and Ron Mack, University of Maine. William Coli, IPM Coordinator, UMass provided overall project direction for all of the commodity surveys. Margaret Christie of UMass coordinated survey instrument design and mailing, Bert Szala of UMass oversaw data entry, error checking and results compilation, and Judy Kolb, UMass typed data results.