Integrated pest management (IPM) is a systematic approach to managing pests that focuses on long-term prevention or suppression with minimal impact on human health, the environment, and nontarget organisms. IPM incorporates all reasonable measures to prevent pest problems by properly identifying pests, monitoring population dynamics, and using cultural, physical, biological, or chemical pest population control methods to reduce pests to acceptable levels as outlined in Part 325 of the NYS Department of Environmental Conservation rules and regulations relating to the application of pesticides. This official definition does not change the concept of IPM, but it supports and encourages the grower to exercise more time, thought, and creativity in pest prevention. An upgrading of the facility may be the key to management of some pests. For example, building a screened cover for vents or heating the floor may solve pest problems. The site history determines an IPM strategy; correct pest identification and better understanding of pest biology are critical to successful IPM. With a long-term perspective it is easier to see that an investment in IPM can pay for itself in a higher-quality crop and a cleaner environment. In reality, all growers currently practice some level of IPM. It is a site-specific strategy for managing pests that relies on understanding pest biology.

3.2 Basics of Integrated Pest Management

Many floral crops require specific cultural conditions and preventive strategies for pest management. Learning to grow a crop may take several seasons of personal experience, absorbing the details from colleagues, suppliers, special classes, extension programs, and reading. Unique crop susceptibilities to insects and disease and the features of a particular greenhouse determine which IPM tools will be necessary, such as screening, seed or bulb treatment, careful examination of newly arrived stock plants, or ventilation to reduce humidity. Each operation must develop its own IPM strategy to produce high-quality crops and thrive economically. Continuous education is required as new pests, crops, and management techniques appear.

Through each year’s experience and attendance at professional meetings, you will increase your understanding of the impacts of sanitation, early detection of pests, proper timing of sprays, and effective use of new products. You will adopt new IPM practices over time as you increase your knowledge and skill levels. Many of the methods incorporated in an IPM strategy are logical greenhouse operating procedures and basic horticultural practices. The following methods will produce a healthier crop, prevent many pest problems, and isolate pests to smaller areas in the greenhouse: preseason cleanup, cultural practices in IPM, scouting, careful identification of pests, examination of plants upon arrival, and keeping records. The primary goal of IPM is to optimize pest management in an economically and ecologically sound way.

3.2.1 Preseason Cleanup

Before introducing a new crop into the greenhouse, it is extremely important to eliminate the pests from the previous crop. Remove all plant debris from the site and compost it to kill pathogens and insect and mite pests. Clean up spilled media on benches because it is likely to contain fungal spores, nematodes, or insect eggs, larvae, or pupae. Remove any weeds in the greenhouse by hand pulling or use an herbicide followed by removal. Please refer to the section “Management of Greenhouse Weeds” (and Table 9.2.1) before using an herbicide indoors and around the greenhouse to prevent damage to future crops. Clean the floor thoroughly. Next disinfest surfaces with a labeled product, being careful to wear goggles or other protective clothing as described on the label. Chlorine bleach may be used for pots or flats, but it is not approved for application to greenhouse walls, benches, or flooring. If using bleach, make up fresh solutions regularly because the active components will dissipate after two hours. If cut flowers are grown in ground beds, pasteurization of the soil by steam is recommended. See Table 3.3.2.

A fallow period of four weeks will reduce the pest load considerably, but having an empty greenhouse for even two weeks can help. The house should be free of both crops and weeds. To determine whether thrips, fungus gnats, or other insects are present, set up yellow sticky cards and indicator plants after watering all benches and the floor. Close up the greenhouse (turn on the heat to break dormancy in winter). Observe any insects that are trapped on the cards after two days.

3.2.2 Cultural Practices in Integrated Pest Management

Proper plant nutrition balance, water pH, and fertilizer salt concentration are critical to plant health. Many insects and diseases have an advantage when the plant is compromised by excess amounts of nitrogen, excess fertilizer salts in solution, or deficiencies in calcium or other nutrients. Floral crops differ in their temperature requirements; recording maximum and minimum temperatures will help determine whether the heating or cooling is set appropriately for the species grown. Appropriate growing conditions allow the plant to develop its natural resistance to the fullest. Plant defense mechanisms include the physical barriers of strong stems, sturdy cell walls, and waxy cuticle as well as the ability to manufacture toxic response compounds to discourage insect feeding and resist infection.

Testing water and nutrient solutions for pH and electrical conductivity (EC) has become an industry standard practice since it is easy and inexpensive. Problems can be detected before a major crop loss. Where a large volume of any species is grown, such as chrysanthemum, snapdragon, or rose, it makes sense to send in foliar samples to a laboratory for analysis on a monthly basis to determine changing fertility needs.

Ventilation and bottom heat to reduce leaf wetness and relative humidity are extremely important ways to prevent disease problems. A standard IPM practice during cloudy or rainy weather is timing a complete air exchange in the afternoon. The drier outside air will reduce the humidity overnight. Horizontal air flow systems also help to dry plants.

Pinching off damaged plant parts, flowers, and spotted leaves (and those with insect larvae or egg deposits) can be a very effective way of reducing the spread of pests in the greenhouse. The plant debris should be placed immediately in a covered container before being removed from the premises for composting.

Workers in the greenhouse are frequently the mechanism for dispersal of insects and disease. People should try to avoid moving infested plants. For example, plants with powdery mildew or thrips should not be touched or moved immediately before handling clean, healthy plants. When pinching plants or making cuttings, be sure to disinfest tools periodically to avoid spreading pathogens into the wounds. Knives can be dipped in a 70 percent alcohol solution to kill bacteria. For more information on disinfectants, see Tips on Managing Floriculture Crop Problems, available from the Ohio Florists Association Services Inc., 2130 Stella Court, Suite 200, Columbus, OH 43215.

3.2.3 Scouting

Monitoring or scouting is the regular, systematic inspection of the plants, benches, floors, and exteriors to identify and assess insect, disease, weed, and cultural problems. It includes inspection of foliage, flowers, and root systems; determination of soil pH and soluble salts; and the use of insect traps. Other monitoring tools include sentinel and indicator plants, disease detection kits, and the submission of plant or soil samples to diagnostic labs for analysis. Furthermore, monitoring includes an overall inspection of the greenhouse for production practices and greenhouse conditions that contribute to pest problems, such as watering nozzles left on floors, areas of standing water, or poor air movement.

This information is then used to decide whether action is needed and which techniques to use. Accurate information gathered through scouting is the basis for sound pest management decisions. Timely crop monitoring identifies situations where pests are absent or are at levels well below those necessary to cause damage, thus preventing unnecessary control applications and expenditures. When the focal point of an infestation is determined early, a few plants can be spot treated or rogued by placement in a plastic bag before removal, and the rest of the crop can be treated more effectively.

The person who scouts may be a designated employee or an outside professional who visits weekly during the crop. A scout develops a systematic way of moving through the greenhouse so as not to miss any groups of plants hanging or on the benches. The first step in scouting is to look for deviations from normal in the height and color of the crop. Next, individual plants are examined starting at the soil line. The stem and undersides of the lower leaves are inspected for discoloration, signs or symptoms of pests, or indications of nutrient disorders. Each level of the plant is inspected, including the tender new growth and flowers. Plants should be turned out of the pot and the root system examined for evidence of insect or disease damage.

3.2.3.1 Scouting Guidelines

Scouting procedures for most greenhouse-grown crops are based on visual observations. The common pests that attack greenhouse crops do not distribute themselves evenly throughout the crop. Therefore, it is imperative to scout the entire greenhouse in a consistent, uniform pattern that includes plants growing on the ground, plants set on benches, and plants hanging from the greenhouse frame. The number of plants, their size, and the location of the benches influence the pattern and time needed to scout. The more plants inspected the better your scouting procedures.

Scout the crop on a regular basis. Usually a weekly inspection is adequate to make pest management decisions; twice a week is ideal. Follow the same pattern each week. A thorough greenhouse inspection will reveal the location and severity of any current pest problems, such as whiteflies, aphids, mites, fungus gnats, or thrips. When you find a plant with a pest, flag it. In this way you can relocate the pot and study the pest development. The flagged plant is your indicator plant. If you treat, later go back into the greenhouse to your indicator plant and turn the leaves over to see if you have controlled the pest.

Use a field data sheet to record the identification, location, and severity of all pests present, and record the effectiveness of any treatments.

3.2.3.2 Individual Plant Inspection

Inspect the entire plant, including the soil surface, for the presence of arthropod pests and plant diseases. Look at the plant systematically each time. Begin at the bottom and work up. Look at the older leaves, the young, tender leaves, and the flush growth. Check the root systems on a few plants each week to monitor for root tip burn or fungal root rot. When the crop is young, it is important to check all the leaves on the plant. Because a majority of arthropod pests prefer the underside of a leaf, it is important to turn the leaves over to check for pests. Record the following on a field data sheet: (1) number of plants inspected, (2) type of pests or plant abnormalities, (3) location of the plant in the greenhouse, and (4) estimated number of pests present.

3.2.3.3 Yellow Sticky Cards

For arthropod pests, yellow sticky cards are an excellent supplement to pest observations on plants. In the areas to be scouted, place yellow sticky cards in a grid pattern approximately every 1,000 square feet. There are a few ways to place the yellow sticky cards in the crop. We suggest attaching each card vertically to a bamboo stake with a clothespin. As the crop grows, cards can be moved up. Designate the location of each sticky card on a map of the greenhouse. Check the sticky cards every scouting visit (twice a week if possible). Record the total number of whiteflies, thrips, fungus gnats, winged aphids, and shore flies from each card on the field data sheet.

Yellow sticky cards allow you to watch population trends. If you check them daily, you can combine the information with the plant counts and predict when to spray. Change the cards when necessary.

Detailed descriptions for monitoring floral crops for specific disease and insect pests follow in the sections on diseases and arthropod pests. Additional information on scouting equipment and techniques and key pests on your crops is presented in Integrated Pest Management for Bedding Plants: A Scouting and Pest Management Guide, Cornell Cooperative Extension 102IPM407, available at http://nysipmp.cornell.edu/publications.

3.2.4 Pest Identification

Each crop has a set of typical pests that will attack under certain conditions. This information should be available on site in a set of references to aid in diagnosis and to help understand the life cycle of the pest. Correct identification is critical to selection of appropriate management tactics, because individual species can display different susceptibilities to chemical and biological controls. Because new pest and host combinations appear each year to surprise everyone, a greenhouse operation should budget for professional diagnosis and soil analysis several times a year to make decisions that really solve problems. It is advisable to phone ahead to the laboratory and get instructions on how to take samples and ship them to arrive in good condition for analysis.

3.2.5 Inspection upon Arrival

When new plants arrive at the greenhouse, examine them closely for signs of infection, including leaf spots and root rots, and evidence of damage in shipping, such as rough handling or chilling in transit, that could lead to disease. If you suspect that the plants are diseased or infested with insects or mites, do not set them immediately next to a shipment from another supplier. If necessary, remove lower or damaged leaves to avoid spread of pathogens like Botrytis. Keep the new plants segregated until you have had time to observe them, preferably in a low-traffic area designated with a sign to employees asking them not to touch. Bacteria, fungal spores, and mechanically transmitted viruses are easily moved by workers from infected plants to healthy plants. Make your decision whether treatment is needed from the first sign of symptoms of disease or insects or mites. Most fungicides act as spore germination inhibitors, preventing infection, rather than by curative action. It is much easier to manage a disease or insect infestation by treating a grouping of small plants rather than larger plants where the dense canopy prevents thorough coverage.

3.2.6 Keeping Records

Brief, accurate information recorded on a field data sheet is one of the best tools available to make a pest management decision. IPM programs rely on records for pest management decisions. The time spent recording information on a ledger or data sheet may seem hard to justify, but pest managers trying to diagnose a problem without records are at a disadvantage and may overlook the potential causes of the problem. When program evaluations and future plans are developed, records and data analyses are invaluable. All production inputs must be recorded.

Field data sheets, maps of the greenhouse, grower reports, and spray records are mandatory parts of an IPM program. See the discussion of scouting procedures for the types of information recorded on a field data sheet. Maps of the greenhouse are useful to plot pest counts from sticky cards. Visual observations of pest infestations can also be drawn on the map. Maps can then be evaluated for movement of a pest infestation. The grower report is a way to consolidate the field data sheets and report the status of the crop to the grower. Spray records should include, but should not be limited to, the date and time of application, areas treated, name of the pest, pesticide used, rate and amount applied, method of application, time required to apply the pesticide, and effectiveness.

In the beginning, records do not mean much. But they become valuable when you sit down with your employees to identify trends and direction for your pest management program

3.3 Sanitation and Sterilization

Procedures that minimize the introduction of pests into the cropping system help prevent problems caused by disease organisms, arthropods, weeds, and other organisms. Procedures should be designed for handling growing mixes, tools, and equipment to avoid contamination of the growing medium. Before incoming plant material is allowed into the growing area, it should be inspected for pests.

3.3.1 General Care

Washing hands between greenhouse crop production procedures; wearing clean clothing; and avoiding placing plants, flats, and hose ends on floors or other contaminated surfaces will help keep crops free of pests.

3.3.2 Disinfestation of Benches and Equipment

Bench surfaces, tools, plastic pots, and other crop production equipment should be disinfested between uses. Although heat is an effective sterilant, materials such as plastics may not withstand high-temperature treatment. Chemical disinfestants are more commonly used. Labeled products are listed in Table 3.3.1.

3.3.3 Pasteurization Methods (Steam and Fumigants)

Pasteurization of the growing medium is required if soil, sand, or other shallow-dug material exposed to pests is used. Table 3.3.2 lists heat and labeled chemical methods of pasteurization.

Table 3.3.1. Disinfectants for benches and equipment
*Chemical*	*Brand Name/Formulation*	*EPA Reg. No.*	*REI§*
sodium hypochlorite	Clorox/6.15% sodium hypochlorite	67619-8	0
Use in a 1:9 dilution (1 part bleach to 9 parts water is a 10 percent solution) on inanimate surfaces with adequate ventilation. Useful for disinfesting pots, tools, benches, potting surfaces, and shelves. For pots, soak directly in 10 percent Clorox solution for 10 min. Clorox will bleach clothing and can irritate eyes and unprotected skin. Use with care. Injury has occurred to mums set upon capillary mats treated with sodium hypochlorite. Rinse treated areas thoroughly and ventilate after treatment.
ammonium chloride	Physan 20/20%	55364-5	12
	Green-Shield 20%	499-368
For control of fungi, bacteria, and algae on hard, inanimate surfaces. Registered for use in greenhouses.
hydrogen dioxide	ZeroTol/27% hydrogen dioxide	70299-1	0
For use as a surface disinfestant to reduce problems with fungi, bacteria, and algae.
§Restricted-entry interval (in hours)

Table 3.3.2. Sterilization methods (steam and fumigants)
*Method/Chemical*	*Brand Name/Formulation*	*EPA Reg. No.*
steam	NA	NA
Effective against weed seeds, fungi, bacteria, nematodes, and soil insects.
Raise temperature of entire soil mass to 71° C (160° F) for 1/2 hr. Check with thermometer at center of soil mass. If an accurate temperature reading of 71° C cannot be assured, heat the soil to 82° C (180° F) for 1/2 hr. Add organic matter, superphosphate, and other fertilizers before sterilization. Sterilize tools and potting bench. Avoid recontamination. Do not place unsterilized flats, pots, tools, or watering systems on sterilized areas. Leach soil after sterilization to reduce accumulation of soluble salts. Neutralizing amines such as diethylaminoethanol are often used in steam condensate lines to prevent acid corrosion. This material may cause chlorosis and growth abnormalities in many plants. Age sterilized soil for two to three weeks before use to allow toxic materials to dissipate.
aerated steam	NA	NA
Effective against some weed seeds, pathogenic fungi, steam bacteria, and nematodes as well as soil insects.
Aerated steam treatment is preferable to steam treatment because it kills the pathogenic microorganisms and allows some of the beneficial organisms to survive. Aerated steam is best suited for use with potting media and well-raised benches. Add organic matter, fertilizers, and other soil amendments before sterilization. Introduce sufficient air into the steam line to lower the temperature to supply 60° C (140° F) to the soil mass. Measure temperature at the coldest spot with a thermometer until 60° C is reached, and continue treatment for 30 min. Take strict precautions to prevent recontamination of steamed soil.
chloropicrin	*Chlor-O-Pic/96.5% chloropicrin	5785-17
Effective against weeds, most fungi, nematodes, and soil insects. Controls Verticillium.
Use with extreme care, especially if chloropicrin is being applied within a greenhouse structure. Protect workers during application according to label guidelines. Fumes are toxic to plants, so greenhouse must be empty. Chloropicrin works best when soil temperature is 16°–32° C (60°–90° F). Aerate soil for 10–21 days before planting.
metam sodium	Vapam	5481-468
Effective against nematodes, most weeds, and fungi.
Follow label precautions to ensure worker safety. Do not use in an enclosed area without adequate ventilation. Treat only a small area at a time, then apply water to carry the chemical through the layer to be fumigated. Do not plant for two to three weeks after treatment, then make test plantings of seedlings or cuttings. The minimum soil temperature for treatment is 10° C (50° F). If the soil is cold or excessively wet, wait three to four weeks after treatment. Fumes are toxic to plants so greenhouse must be empty.
*methyl bromide	*Brom-O-Gas/98% methyl bromide	5785-42
plus chloropicrin	plus 2% chloropicrin
Effective against weeds, insects, nematodes, bacteria, and most fungi. Verticillium is not adequately controlled; chloropicrin is the best choice where this fungus is limiting crop productivity.
Follow label precautions to ensure worker safety. A tight seal with a plastic cover is necessary to prevent escape of the gas. Soil must be thoroughly aired for three to seven days before use. Do not use bromine-containing fumigants for treating soils to be planted to carnations or salvia. Fumes are slightly toxic to plants; can be used in greenhouse with vents open.
Before purchase or use, check the registration status of methyl bromide.
dazomet	Basamid Granular 99%	70051-101
Effective against many weeds, nematodes, root rot, and wilt diseases. See label for instructions. REI: 24 hours.

Pest Management Guidelines A Cornell Cooperative Extension Publication	Cornell Guide for Pest Management of Greenhouse Floral Crops
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