Introduction

          Integrated Pest Management, or IPM, is a decision-making process that aims to suppress pest problems with procedures that are effective, economical, and environmentally-friendly.  This process includes the proper use of pesticides and in some situations a successful program will result in fewer pesticide applications.

           A new IPM program should be kept simple.  Begin by focusing on only a few plants and their associated problems, thus allowing nursery management to become familiar with the process without becoming overwhelmed with multiple simultaneous changes.  Once the initial problems are solved, the program can be expanded.

           The following information was designed to be a step-by-step process to starting, developing, and maintaining a program that is successful and adaptable to the special needs of each nursery.

Monitoring of plants

           Monitoring is the regular inspection of plants to detect problems caused by pests or environmental disorders.  Monitoring is the core component of Integrated Pest Management, without it an IPM program does not exist.

           The aim of monitoring is to detect plant problems as they start.  The information gathered during inspections will allow the site manager to make sound decisions on the need for cultural remedies or pesticide applications.  If successful, the plant problems will be found at the nursery, not by the customer receiving a shipment.

Dedicate one person for the monitoring of the nursery.

           The most effective way to build a successful IPM program is for nursery management to assign one person the task of crop inspection.

            This person, often called a “scout”, must be given enough time to tour the facility and look for plant problems.  This time must be dedicated exclusively to monitoring;  the “scout” should not be expected to perform other duties such as shipping, pruning or weeding during the inspection.

Allocate the required amount of time for monitoring.

            Each nursery must determine how much time is necessary to conduct adequate monitoring.  For some nurseries, one day every second week may be adequate, while others may require 2 or 3 days a week.

           Two factors influence the amount of time required for monitoring.
   - First, nurseries that grow a large variety of plants will take longer to monitor than nurseries growing a smaller selection.  More plant varieties mean more potential pest problems and increase the time required to inspect the plants.

   - Second, the abundance of pest problems is seasonal.  Typically, spring and summer months present more pest problems to monitor than fall and winter months.  Similarly, spring monitoring can take twice as long as summer monitoring due to the presence of more pests.

Learn to recognize "normal" from "not normal".

            The monitoring scout must be able to recognize when a plant is not growing normally.  For example, leaves with two colours are “normal” on variegated plant cultivars, but are “not normal” on plants suffering from nutrient deficiencies.

           The monitoring scout must also be able to recognize plant problems as they start.  Many problems first appear on the newest foliage and will cause pierced, deformed, or discolored leaves.

Use a variety of monitoring methods.

            There are many different ways to monitor plants, and different problems require different monitoring methods.

           Some of the most common monitoring methods are:

   - Inspecting the plant visually, looking for damaged leaves, the presence of insects, or discolored plant parts.

   - Beating branches over a white sheet of paper attached to a clipboard;  this dislodges insects such as spider mites and root weevils.

   - Installing colored or pheromone traps to capture the adult stage of many insects such as thrips, tree borers and many moths.

   - Using indicator trees to monitor specific insect pests at the most appropriate times.  For more information on this topic, please go to the page "Indicator trees".

   - Monitoring weather conditions that favor the development of certain diseases or the emergence of insects.

Seek the observations of field supervisors.

           Most nurseries have field personnel and supervisors dedicated to specific production areas.  They look at the plants on a daily basis and will notice when a pest infestation is starting or when a plant is beginning to look “not normal”.

           The monitoring scout should regularly discuss the crop condition with the field supervisors, as their observations are a time-saving method of going directly to infected plants.

Examine plants with many predator insects.

           In their adult stage, many predator insects are very efficient in finding small infestations of aphids, spider mites, and thrips.  An abundance of predators in a bed of plants is a warning signal that a pest problem may be developing.

Use appropriate field equipment.

           The following tools are useful for field monitoring:

   - A hand lens, sixteen power magnification, can be used to examine the insects and diseases structures in the field.  Hand-held lenses sell for about $30.
   - Hand pruners to remove plant parts.  The instruments must be kept sharp and disinfected regularly.
   - Containers and bags to collect insect and leaf samples.
   - A trowel and a shovel used to examine the soil at the base of the plants.
   - A notebook and a pen used to record observations and counts.

Identification of plant problems

            Before selecting a treatment that will be effective, proper identification of the problem is essential.  Different problems require different solutions, for example spraying for insects will not solve a plant problem caused by a disease.

Look at the whole plant, not just the top growth.

           A thorough examination of the plant is often the only way to obtain an accurate diagnosis of the underlying problem.

           Many plant problems are caused by environmental factors that cannot be fixed by spraying pesticides.  For example, a plant that is wilting may suffer from lack of water, root rot from excessive water, or root damage caused by rodent.

           There are many other reasons to examine a plant thoroughly.  Insects such as leafhoppers and sawflies hide on the underside of the leaves during their young stages and are normally not detected until they have caused serious damage.

Make counts of plants with pest problems.

           Counts are a written record of the pest found and the number of plants affected.  They make a useful permanent record to verify whether a problem is increasing, disappearing, or whether a pesticide application has been effective.

           The monitoring scout should make enough counts in order to have data that is reasonably accurate and shows that pest numbers are sufficient to justify treatments.  The number of counts will vary with each problem and the expertise of each person.  Twenty counts may be sufficient in some situations, whereas five hundred counts may be required in others.

Seek professional help with difficult problems.

           Monitoring scouts should develop a list of contacts in their area that can help with specific problems.  The Plant Diagnostic Lab, based in Abbotsford, provides a fee-for-service to industry professionals and can help diagnose most plant problems.

Use appropriate laboratory equipment.

           The following equipment is useful in the identification of plant problems:

   - Have a work space that includes a table, shelves and a refrigerator.  This space is used to examine plant parts more closely and to store samples.
   - Use a microscope to recognize insects and diseases more rapidly and examine small features more closely.  In Canada, microscopes of acceptable quality range in price from $400 to $2,000.
   - Build a library of books and articles that have colour pictures, technical descriptions, or control recommendations.  Many good publications are available for nurseries and a list of suggested books is given later on this page.

Treatment of plant problems

            When infection levels justify it, a treatment is often necessary to fix a plant problem.  There are many situations where non-chemical approaches can be very effective, for example, pruning out the infected plant parts can successfully control some diseases.

Use pesticides only when justified.

           There are three common situations that justify the use of pesticides in nurseries.

   - First, when the pest problem can seriously damage the plant.  Insects such as bark borers, sawflies, or root weevils can kill an affected plant.  In most cases, the only effective control is to apply pesticides at the proper time in the pest life cycle.

   - Second, when the pest problem is present on plants ready for sale.  Insect problems which may be minor in nursery production can trigger complaints by customers.  Aphids and thrips are examples of minor pests which should be controlled before the plants are shipped.

   - Third, pesticide use is condoned when the pest problem will bother the nursery workers.  Aphids on the new growth of field-grown trees will cause little damage to the plants but will annoy the workers who walk through the plants for routine activities such as pruning or tying.

Determine if other plants should be treated at the same time.

            If a pesticide application is required, there may be other plants in the vicinity that can be treated at the same time.  The pest problem on these plants may be minor, but there is an economy of scale in treating more plants simultaneously.

           Also, attempt to combine treatments.  If the same area is sprayed one week for one problem and the following week for another problem, it may become an inconvenience for work scheduling.

Use pesticides in the safest possible way.

           When a pesticide is applied, ensure the area is clear of people, and follow provincial regulations for restricted re-entry intervals.  Generally, the re-entry interval is 24 hours for most herbicides and fungicides and 48 to 72 hours for many insecticides.

           Whenever possible, select a pesticide of low toxicity to preserve naturally-occurring predators and parasites.

           Most importantly, follow label instructions for application rates and safety precautions.

Verify the treatment was successful.

           An IPM program will be adopted by nursery management if the pest problems are properly controlled.  It is important to examine the plants following a pesticide application or other control method to verify its effectiveness.

            In many situations, a pesticide application that was not successful can be traced back to a faulty application.  Common errors include driving the tractor too rapidly, not getting thorough coverage of the plants, or plugged nozzles.

Build a calendar of pest problems.

            By keeping a record of when the pest appeared and the date of treatment applications, a monitoring scout can inspect the plants at the start of seasonal pest problems and have a program in place before damage is done.

           On the page Seasonal Pests, you will find a calendar of seasonal pest problems for plants in the Southern Interior of British Columbia.

Ask the question:  Is there any way to control the problem without pesticides?

           After a successful pesticide treatment, an important question should be asked:

Is there anything else than can be done in the future to eliminate the need to apply pesticide for this problem?

           In some cases, pest problems come back annually and the only option is to apply a pesticide at the proper time.  In other situations, the production practices can be modified to make environmental conditions less favourable for the pest.  For example, a nursery may drop a plant variety that is very susceptible to aphids or change their irrigation schedule to prevent leaf spot infections.

Other resources

Publications

- Nursery & Landscape "Pest Management & Production Guide”
David Woodske, Editor, B.C. Ministry of Agriculture and Food and the B.C. Landscape & Nursery Association, 2002.
This publication has an extensive pest management section, with control recommendations that include chemical and non-chemical options.
Sold by the B.C. Landscape and Nursery Association, Surrey, telephone 1-604-574-7772. Website: www.bclna.com/index.htm


-“Integrated Pest Management Manual for Landscape Pests in British Columbia”
L.A. Gilkeson and R.W. Adams, B.C. Ministry of Environment, Lands and Parks, 2000.
This recent publication has a complete chapter on the components of Integrated Pest Management, and other chapters on IPM practices for specific situations such as weeds in lawns, insects on trees and shrubs, or greenhouses.
Available from the Office Products Centre, 1-800-282-7955, or at www.env.gov.bc.ca/epd/epdpa/ipmp/ipm-manuals.htm


- “Integrated Pest Management for Floriculture and Nurseries"
A new manual from the University of California that covers bulbs, cut flowers, potted flowering plants, foliage plants, bedding plants, and ornamental trees and shrubs.
It sells for $45 (US dollars) and is available from the Communication Services of the University of California in Oakland, 1-510-642-2431 or visit the web site http://ipm.ucdavis.edu/IPMPROJECT/ADS/manual_floriculture.html 


Web sites

- “InfoBasket”
A web site maintained by the B.C. Ministry of Agriculture, Food and Fisheries with links to a large number of other websites on Integrated Pest Management.  The address is: http://infobasket.gov.bc.ca/portal/server.pt?
From the home page, select a "community" (such as "Ornamentals"), then select the folders "Production" to reach "Plant Health Management", which includes links to Integrated Pest Management sites.