Integrated Pest Management in the Nursery

1. Integrated Pest Management
2. Monitoring
3. Models to Predict Insect Emergence
4. Indicator Plants
5. Action Thresholds
6. Good Crop Management
7. Best Management Practices
8. Blank Template for Monitoring DataSymptoms and Possible Causes of Injury
9. Monitoring for Specific Insects
10. Some Sources of Monitoring Supplies
11. References
12. Related Links

Integrated Pest Management (IPM)

Intergrated Pest Management (IPM) is a decision-making process that integrates all available tools to reduce pest populations to an acceptable level in a cost-effective, environmentally rational manner. These tools include: Monitoring, Cultural Control (sanitation, weed control, cultivar resistance), Physical Control (quarantine new plants, mechanical cultivation), Biological Control (parasites and predators), and Chemical Control (based on monitoring data, biorational products).

An IPM program needs to be custom-designed for each nursery crop since every situation is different. The Ontario greenhouse industry uses a 3-phase approach for implementing IPM programs:

PHASE I is getting started with pest and disease monitoring (weekly).

PHASE II is a modified spray program, using the monitoring data to make control decisions.

PHASE III is the incorporation of biological control into the program (where possible) and using compatible sprays as required.

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Monitoring

Monitoringis the most important part of an Integrated Pest Management program in the nursery. Here are a few points that I have found to make Monitoring more efficient:

• Where possible, a specified Pest Technician(s) should be responsible for monitoring and it should be carried out on a regular basis (e.g. Mondays and Thursdays).
• The entire plant production area should be physically examined (i.e. walked through) at least once a week.
• Monitoring Record Sheets should be created for record keeping. These sheets should include: DATE, area, host plant, pest or condition, GDD or Plant Indicator Species development (see Table 1 below), pesticides used etc.
• Have copies of plant production area MAPS and include site names, block labels, N-S-E-W direction, landmarks and key plants in the blocks for better monitoring records.
• In the field, use clip boards and pencils for monitoring record sheets and maps (pencils do not smudge when paper gets wet).
• Maintain a "Monitoring Work Station" where all staff can record monitoring information, check monitoring logs, review maps of the nursery property, review diagnostic books and other resources, review information on quarantined and other nursery pests plus write pest sightings on a message board for the pest technician.
• Nursery staff from other crews (i.e. weeding, pruning etc.) should also be included in the monitoring program as they can flag plants with unusual symptoms and bring it to the attention of the pest technician (try to incorporate rewards and employee recognition into the monitoring program).

  AREA: Farm A-Block #1

  Date: 2001	Host	Pest/Problem	GDD/Plant	Pest- icides
  April 28	Thuja occidentalis 'Fastigiata'	Webbing, dirty foliage, some bronzing, shake test revealed tiny specks on paper - spruce spider mites? 40% of 'Fastigiata' affected (30% on each plant)	60, Cercis canadensis start bloom	none

  
  
• Previous monitoring record sheets should be kept in a binder at the "Monitoring Work Station" for all staff to review (try keeping the results in a computer worksheet software program for easier access and organization). These records can be used to predict future trends in pests problems and hot spots in the nursery.
• Read up on cultural and pest problems that are known to occur on the plants in your nursery and know their life cycles (See OMAFRA Infosheet: Reference List for Ornamental Plants)
• Be nosy, most insects hide on the undersides of leaves, twigs and branch crotches. In some cases, roots should be examined to rule out disease or root-feeding insects.

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Models to Predict Insect Emergence:

1. Plant Phenology indicators use the timing of flower and fruit development of common ornamentals, to approximate when known insect pests will be emerging. For example, when the Magnolia x Soulangiana are in pink bud, the spruce gall adelgid nymphs are active and susceptible to chemical control. This system works well since both plants and insects require certain amounts of heat each day to develop. This type of information can be found in the OMAFRA Nursery-Landscape Plant Crop Update and OMAFRA publication 383, Nursery and Landscape Plant Production.
   
   
2. You can also calculate the amount of daily heat by calculating Growing Degree Days (GDD's). Use the daily maximum and minimum temperatures from your local weather station or from Environment Canada. Many references exist which give GDD -type information for insect development. (Examples of GDD base temperatures include 10°C and 50°F.)

   Equation: (Max + Min )/2 - Base Temperature = # GDD's

   Example: (14^°C + 4^°C )/2 - 10^°C = 0 GDD's ( at base = 10^°C)

3. You can use insect Traps to help indicate development and emergence of insect pests in the nursery.
   • Baited traps - use pheromone (mating) lures or other lures (e.g. floral lures) to attract insects. Place at least 2 traps per monitoring area about 1 week before adults are expected to emerge. Traps should be placed on the windward side of the monitoring area. Try to be consistent with pheromone types and brands.
   • Refuges - provide places for insects to hide (e.g. burlap traps for black vine weevil adults, gypsy moth larvae).
   • Yellow sticky traps - catch flying insects (e.g. aphids, whiteflies, leafminer adults, thrips, leafhoppers). You must be familiar with insect identification to be successful.
   • Tape - wrap tape around stems and small branches (sticky side out) to capture scale crawlers (for monitoring purposes only).
   • Tapping trays - a white surface (e.g. paper on clipboard) held beneath a tapped branch is useful for monitoring mites, plant bugs (e.g. honeylocust) and caterpillar droppings.
   • Pitfall traps - a cup shaped tray placed in the ground (top of tray is level with ground surface) can be used to monitor flightless pests (such as root weevil adults).
   
   
4. Visual symptoms (e.g. chewed notches in leaves) can provide the most accurate information for pest populations and damage severity in the nursery. Unfortuneately, this is also the most time-consuming way of monitoring pest populations. Carry flags and flagging tape so you can mark which plants are most infested, in order to monitor pest development and evaluate pest control methods.

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Indicator Plants

Indicator Plants are plants in the nursery that seem to attract specific pests first. These indicator plants should be examined first, at the beginning of each monitoring cycle. By knowing your Indicator Plants, you can often catch pests before they reach economically damaging populations. For example:

(Can you name some others?)

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Action Thresholds

Action Thresholds determine what pest levels can be tolerated and when control action is required (e.g. pesticide). This may be expressed as the number of insects caught per week. In most situations, this information will become obvious to the grower after just a few months of monitoring. It should not require any calculations or difficult interpretation of monitoring results. Action thresholds will vary between individual operations, value of plant material, type of pest etc.

Good Crop Management

Good Crop Management is essential in producing healthy ornamentals. As a grower you have a major influence on plant health through environment (media, water/irrigation, temperature, light, spacing etc.) and nutrients (rate, delivery). As you know, slight changes in environment and fertilizer can have dramatic effects on plant health. For instance, by changing the structure of the container media, one grower was able to increase the shoot growth of Prunus x cistena by about 40% ! By making minor adjustments in your practices and materials, you can fine-tune your production practices and cause increased plant health and plant performance. Sometimes these changes come about by error (as in the case of Prunus x cistena), but the bottom line is that the grower was confident enough to make the change and organized enough to note the difference in growth. It all comes back to…MONITORING.

Best Management Practices (BMP's)

Best Management Practices (BMP's) are the outcome of Good Crop Management. Every grower has a set of guidelines that they follow to produce plants in a responsible manner. Many BMP's pertain to sound water and fertilizer use (both for healthy plants and a healthy environment), the recycling of plastics and the responsible use of pesticides. By monitoring irrigation water quality and analyzing leachate, you can produce the healthier plants by catching problems early.

Test IRRIGATION WATER (one test from each water source) in the a) Spring, b) summer and c) fall. It is good to test at least 3 times per year since water levels change throughout the seasons. Have the samples tested at an accredited lab (see page 12 of OMAFRA Nursery-Landscape Plant Production) and make sure they test for:

• pH [want between 5.4-7.0]
• EC (Electrical conductivity, soluble salts) [want maximum of 1.25 for seedlings/liners, may be higher (up to 2.0) for use on woody ornamentals]
• Total Carbonates (CaCO3) [up to 100 ppm]
• Bicarbonates (HCO3) [up to 120-150 ppm] (bicarbonates are responsible for raising the pH of water and media]
• Sodium (Na) [up to 50-69 ppm (problem: can be toxic to ornamentals)
• Chloride (Cl) [up to 70-140 ppm (problem: can be toxic to ornamentals)
• Sulfur (S) [up to 20-30 ppm]
• Sulfates (SO4) [up to 60-90 ppm (some say up to 240 ppm)
• Boron (B) [up to 0.5-0.8 ppm (problem: can be toxic to ornamentals)

Test LEACHATE (pour-through technique) by Virginia Tech Extraction Method (http://www.ces.ncsu.edu/depts/hort/hil/h

il-401.html). Test every 2 weeks. Compare EC and pH over time and monitor fertilizer salts in the soil solution. Over time, you will develop a database that correlates salt levels and pH with healthy plant growth. Spikes in salt levels will be detected early and remedial watering to leach out salts will take care of root problems before they start. Analysis of fertilizer salts will reveal peak levels of fertilizer release and periods when supplemental applications may be warranted.

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Table 1. Blank Template for Monitoring Data (print and use for your data collection)

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Table 2. Symptoms and Possible Causes of Injury

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Table 3. Monitoring for Specific Insects

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Some Sources of Monitoring Supplies:

References: Also see "Reference List for Ornamental Plants"

• Bailey, D., Bilderback, T. and Water, D. Bir. Considerations for Container Production. 1998.NMPro. 14(12):51-57.
• Bloom, T., Straver, B., Brown, W. and Hughers, J. Water Quality for Greenhouse Crops. 1987. OMAFRA Factsheet 87-045 (AGDEX 290/15).
• Gilkeson, L.A. and Adams R.W. IPM Manual for Landscape Pests in British Columbia. 2000. BC Ministry of Environment, Lands and Parks.
• Kessel, C. 1995. IPM strategies for Nurseries: a step by step guide. Ontario Ministry of Agriculture, Food and Rural Affairs.
• Koehler, C.S. 1987. Symptomatology in the Instruction of Landscape Ornamentals Entomology. J of Arboriculture. 13(3):78-80.
• Mathers, H. What You Should Know About Water Quality for Woody Plants. 1998. Oregon State University.
• Murphy, G. and Brown, W. IPM Workshop for Greenhouse Growers. Ontario Ministry of Agriculture, Food and Rural Affairs.
• Nielsen, D.G. 1990. Landscape Integrated Pest Management. J of Arboriculture. 16(10): 253-259.
• Raupp, M.J., Davidson, J.A., Holmes, J.J. and Hellman, J.L. 1985. The Concept of Key Plants in IPM for Landscapes. J of Arboriculture. 11(11):317-322.
• Rose, M.A. What's on Tap? (Water Quality in the Nursery). 1995. Landscape and Nursery Dialog.

Related Links

• OMAFRA Nursery-Landscape Plant Crop Updates
• Publication 383, Nursery and Landscape Plant Production and IPM
• Using The PourThru Procedure For Checking EC and pH For Nursery Crops
• Great Lakes IPM
• Natural Insect Control
• Boreal Labs (hand lens)
• A-Z Microscope

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