Integrated pest management (IPM) is a comprehensive approach to dealing with pests -- from the crawling and flying types to the vegetative kind. IPM is a systems approach.
It’s a series of steps that is repeated or modified, as needed, said Russell Mizell, professor of entomology at the
“IPM includes judicious use of pesticides in careful coordination with other pest-management practices. Restricted labeling of pesticides, pest resistance, safety to nursery personnel and environmental issues are all concerns to nursery managers,” Mizell said. “Nursery managers should seek methods of pest control other than scheduled, preventative, nurserywide pesticide applications.”
The basics
* Prevention. The easiest way to prevent, avoid or eliminate pest problems is to get rid of the plants that pests infest, Mizell said.
Make sure seeds or cuttings are pest free. Apply irrigation at the soil surface to extend the life of foliar-applied insecticide residues.
Eliminate weeds because they’re often infested with insects and mites.
Don’t keep discarded pest-infested plants in or near growing areas.
* Scouting. Keeping accurate records is key to successful scouting. Divide the nursery into units and map the units for efficient scouting, he said. Short-cycle crops may require scouting every three or four days, while longer-cycle crops may require weekly or biweekly scouting.
Pesticide and biocontrol compatibility
Whether natural enemies can be used with pesticides depends upon a number of factors, said Leanne Pundt, IPM specialist at the
Some considerations are: Whether the natural enemy is a predator or parasite; the particular species of natural enemy, and its life stage; and the rate, timing and mode of action of the particular pesticide.
“Pesticides are most harmful to the natural enemy by direct contact,” she said. “However, they can also harm the biological control agents by eliminating the host insect or mite, which eliminates the natural enemies’ food source.”
Sublethal effects can also occur, including effects on reproduction, survival, sex ratio and ability of the natural enemy to forage and find food. Also, harmful effects of pesticides may be due to inert ingredients such as carriers or solvents, she said.
In general, biorational pesticides and fungicides with a more site-specific mode of action are more selective toward natural enemies. For example, pyriproxyfen (Distance) appears harmless to the whitefly parasitoid, Eretmocerus eremicus, but is highly toxic to Encarsia
Wet sprays of horticultural oils and insecticidal soaps are toxic to most natural enemies, especially parasites. Once the residues have dried, they tend to be less harmful. Direct sprays of insecticidal soap are toxic to the predatory mite, P. persimilis, but there are no harmful effects with the insecticidal soap application three days after release.
Rose grower goes green
Grower Paul Zimmerman spent several years looking for and testing organic and natural plant-care products for his retail nursery, Ashdown Roses in
Zimmerman teamed up with Organic Plant Healthcare in
“We began testing the program on over 400 different varieties of roses from all classes back in March 2007,” Zimmerman said. “By May I was so pleased, I put the entire nursery on the program. Garden roses are tough and there is no need for synthetic chemicals to take care of them.”
Healthy soil and healthy plants are the basis of the program.
“We’ve been off chemicals for almost 12 months now. We’ve got 15,000 plants on the program,” Zimmerman said.
The crops grown without synthetic chemicals have taken longer for the tops to form, but the plants have formed fuller roots, have more multibranching and bushier habits and there’s a “far better yield,” he said.
The program also helps attract more beneficials.
Weed-control mulches
Controlling weeds is another part of an IPM program. When herbicides are not an option, there are alternatives to chemical weed control. James Altland, nursery extension specialist, at
* Geotextile disks are gray clothlike disks. They are permeable to water and nutrients but prevent weeds. Only one application is necessary for the life of the crop. The disks are lightweight, easy to install and easy to remove at shipping.
This product generally works only for crops with a single stem, and the trunk must be in the center of the pot for a proper fit. Weeds germinate around the edge of the disk and from the hole cut out for the stem. This product has the propensity to blow away. This can be remedied by using florist greening pins.
*
* Plastic weed disks snap over the rim of the container and essentially lock in place. Because the plastic is relatively rigid, some nurseries have commented that it rubs against plant stems and wounds thin-barked plants. It can be used several times.
* Crumb rubber (shredded tires) is usually processed into batches of different particle size, from 1/4 inch and smaller. The product is black, uniform in particle size, lightweight and relatively dust-free. Rapid drying after irrigation is the primary reason it provides excellent weed control.
Help is available
IPM is not a program of extremes. IPM was designed to minimize inputs of all types. Proper planning and understanding how each step is related will help you develop a successful IPM program. And if you have questions, contact your local extension specialist or state agriculture department.
For more: Russell Mizell,
IPM myths
* IPM always reduces costs.
Monitoring for pests is time-consuming. Costs may initially be higher in the short term. As knowledge is gained over time and scouting and suppression become more efficient, costs will be reduced.
* IPM always reduces pesticide use.
In the short-term, new knowledge may indicate more or different pesticide use. But over the long-term, pesticides will be reduced, eliminated or substituted with less costly alternatives.
* IPM relies strictly on organic controls.
IPM does not by definition eliminate or specify what controls will be necessary.
* IPM relies strictly on biological controls.
While IPM does advocate using the least toxic alternative that minimizes side effects and input costs, often pesticides are the only efficient controls available to treat certain pest outbreaks. Unilateral reliance on chemical controls for any type of pest is a thing of the past. Alternative approaches should be developed.
For more: Russell Mizell,
- Kelli Rodda
May 2008
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Phenology helps improve pest management
Growing conditions can change overnight, so scheduling pest-management treatments by calendar days is ineffective. Because plants are in tune with their environments, they are good indicators of local climatic conditions, said Frederic Miller, horticulture professor at
Observations on buds (swelling, break), leaves (expansion), flowering (initial, full, spent) and fruit (initiation, ripening) are all important biological phenomenon affected by weather and can provide more accurate information on timing of biological events, he said.
Degree days (DDs) are measured by calculating the mean temperature (maximum temperature plus minimum temperature divided by two) for a given 24-hour period and then comparing the mean temperature with a developmental threshold temperature.
For insects, the standard developmental threshold temperature is 50@F, Miller said. DDs are calculated for each 24-hour period and a cumulative total is tallied. As the DDs accumulate each day, insect development also changes.
The eastern tent caterpillar, gypsy moth and ash plant bug eggs hatch at 100-200 DDs base 50.
Because of the DDs range, also use indicator plants. For example, eastern tent caterpillar eggs hatch when Magnolia x soulangiana is in full to late flower and when Fraxinus spp. is breaking bud.
Select any indicator plants that are specific to your monitoring area and have prominent and obvious phenological features.
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Phenology and DDs benefits include reduced volume and cost of pesticides, reduced pesticide applicator exposure and less impact on natural enemies.
“Take advantage of plant phenology and DDs,” Miller said. “Record your DDs, keep records and set up a database.”
For more: Frederic Miller, (815) 280-2740; fmiller@jjc.edu.
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10 important questions on integrated pest management
The Louisiana State University AgCenter advises growers to ask a handful of questions before making pest-management decisions.
1. What pests are present, and in what numbers and stages of development?
2. What conditions exist that may increase or decrease pest problems?
3. What natural enemies of the pests, such as parasites, predators and diseases, are present that may play an important role in control?
4. What amount and type of damage are being caused or may soon be caused by pests?
5. What is the stage of development, condition and value of the crop?
6. What is the potential for economical injury? How much damage is tolerable? Has the action threshold been reached?
7. What are the history and severity of previous infestations at the site? How were those infestations managed? What were the results?
8. What pest-management options are available, and how do the advantages and disadvantages of each apply to the situation?
9. If alternatives are not available, is pesticide treatment justified for the situation? If so, what is the material of choice?
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10. If a pesticide is not justified, what approaches, if any, should be taken? Field scouting, insect trapping and action thresholds can be used to provide much of the information needed to help answer most of these questions.
For more: Clayton A. Hollier, LSU AgCenter, (225) 578-4487; www.lsuagcenter.com.
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Integrated pest management (IPM): A sustainable approach to managing pests by combining biological, cultural, physical and chemical tools in a way that minimizes economic, health and environmental risks (i.e., use of resistant varieties, crop rotation, cultural practices, optimal use of biological control organisms, protective seed treatment; disease-free transplants or rootstock; timeliness of crop cultivation; improved timing of pesticide applications).
Source:
Biocontrol: Using one type of living organism to effect a change in the population density of another organism. In its usage here, it specifically refers to using insects, mites, or nematodes to control common plant pests.
Biorational: Pertains to chemical pesticides and their effect on biocontrol agents. As a rule of thumb, if a compound or substance lacks the ability to kill a biocontrol agent within 24 hours of direct contact, it is considered biorational, but this is debatable.
Kairomone: An allelochemic substance produced by a pest which elicits a response in predators and parasitoids.
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Parasitoid: An organism which lives in or on another organism. This is typically a micro-micro or macro-macro relationship which is temporary. The host typically dies serving the parasitoid, often being no more than an incubator, food source and nursery for the parasitoid’s offspring. The relationship is never symbiotic.
Source: Greenmethods.com.
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