Healthy Plants Require A Steady Scout
May 1, 2013 Whether your profession is landscape, nursery, or agricultural crops, you want to keep plants healthy. This article discusses monitoring and scouting as a critical component of your plant health care program.
IPM, or integrated pest management, is widely presented as an environmentally friendly and sustainable method. It relies on scouting activities and the setting of action thresholds, which together with regular monitoring, are used to prevent pest and disease outbreaks. Farmers and agriculturists can use these techniques to identify the risk of pest and disease outbreaks at an early stage, which allows for the use of less toxic and less severe management options.
You may have heard the term “Plant Health Care” in discussions about IPM. Sometimes, Plant Health Care (PHC) is used interchangeably. In general, however, PHC incorporates a heavier focus on the cultural practices that may cause a plant to decline. For example, at Extension offices throughout Florida, we evaluate and diagnose many samples each day; a large majority of these are suffering from conditions caused by poor cultural or environmental factors, such as overwatering, drought, or improper planting depth. PHC has been used more by the tree care industries, such as certified arborists. IPM, by contrast, is generally thought defined as having a focus more on the pests related to plant disorders. Since PHC can be more holistic in approach, we will use this term for the remainder of the article; keep in mind, it could be used interchangeably with IPM in many cases and can be applicable to agricultural production, container nurseries, and landscapes.
PHC can be further described as a decision-making process that assesses pests, diseases, and disorders together, as opposed to singling out only one problem at a time. PHC decision-making determines management strategies that are both environmentally sound and logical. Numerous control methods may be employed – cultural, mechanical, biological and chemical.
PHC rejects the idea that the mere presence of a problem automatically warrants control measures. PHC incorporates the principle of “managing” the presence of insects and diseases, in contrast to completely eradicating them, so that populations remain below a particular threshold level.
Scouting, is an important component of PHC programs in nursery, field, and landscape settings alike. The term “monitoring” is often used interchangeably with scouting. Monitoring is generally associated with PHC, while scouting is generally associated with IPM. The purpose of regular monitoring is to detect and identify horticultural disorders, diseases, and pest infestations in their early stages. When a problem is identified sooner, as opposed to later, management is easier to achieve.
You should now have a good understanding of what the terms scouting, monitoring, IPM, and PHC mean.
Keep A Close Eye On Plant Health Care
Many horticultural and agricultural professionals keep a scouting/monitoring kit. This is a good idea to ensure that you don’t forget a critical tool. There are commercial kits available, but it is perfectly fine to create your own or purchase a pre-assembled one and add tools as you see fit.
Some suggested pieces in a scouting or monitoring kit include the following:
- Zipper – type bags – for collecting plant samples
- Small jars – for insect collection
- Hand Trowel or plastic shovel – to look for root problems and planting depth without causing damage to the tree
- Magnifying lens – to view and identify extremely small insects
- Binoculars – to inspect taller tree canopies
- Stethoscope – to listen for insects that are feeding on the inside of a tree, such as giant palm weevils in the heads of palms
- Hand pruner – for taking samples or accessing cross sections of branches / palm fronds
- Small knife
- Latex gloves
- Soil probe
- Pen / pencils / permanent markers
- Ruler
- Index Card
- Identification cards / books – such as weed and disease ID books
- Alcohol – for sterilizing pruning tools and for preserving insect samples
- Identification, reporting, and diagnostic forms
- Recording book
There are some very specific scouting/monitoring and threshold guidelines for certain agricultural crops in Florida. There are much fewer guidelines for woody ornamental nurseries, and even fewer for landscapes. This article is intended to provide a general overview of monitoring. We suggest you research your particular crop or industry to determine if specific guidelines exist. For example, there are some very specific guides for tomatoes (http://erec.ifas.ufl.edu/tomato-scouting-guide/general/field-scouting-procedures.shtml).
When monitoring, it is important to first accurately identify plants using their scientific name. This is important because plants of a particular species are more susceptible to certain diseases and disorders. Further, some species may have particular visual attributes that are normal, such as variegations or patterns that might be indicative of disease on another species. The identification component of monitoring is quite simple when you are looking at a single agricultural crop, but can be much more complex in diverse landscapes.
Once the identification stage is complete, the professional should identify significant species and likely stresses. Significant species may be the ones that are most valuable to the landscape and/or the ones that are most prone to pest, disease, or cultural issues. Likely stresses are those diseases, disorders, and pests that are most likely to affect the significant species on the site. The identification of critical plants and stresses helps in prioritizing your work and area of focus.
Site characteristics should be recorded during a monitoring visit. The characteristics noted should include: climate factors (temperature, hardiness zone, precipitation, and urban stress factors), soil data (pH, compaction), injury and stress (drought stress, dieback, wilting, salinity issues), maintenance (irrigation amount and schedule, pruning practices, planting depth, mulching). It also is recommended to prepare a landscape map to integrate all of the above information.
Depending on the agreement you have with your client, you may monitor all or part of the site; in subsequent visits you may monitor all key plants or you might conduct a representative survey. The above steps in conducting scouting / monitoring will be most time-consuming on your first visit to the site. Each visit after this will require less time on your part.
The central activity of your monitoring visit should be the diagnosis of plant problems. Proper identification is important to selecting management techniques that are logical and appropriate. Improper diagnoses may lead to wasteful treatments, unnecessary expense, and unneeded chemical inputs. During diagnosis, it is important to determine both the problem and the cause of the problem. The essence of PHC is to manage the larger cause of the problem to prevent future occurrences. Problems may fall into four general categories:
- Planting and site problems, poor plant selection
- Plant maintenance issues
- Disease
- Pest infestations
During your monitoring visit, the professional should develop strategies for the landscape, nursery, or field. Strategies may combine cultural, mechanical, biological, and chemical techniques to manage or prevent problems, and increase the health of the site. A strategy could be entail reducing the amount of irrigation applied to the landscape or field or could include the replacement of plants that are not well-suited to the site. Each strategy is site- and situation- specific and should take customer expectations and perceptions into consideration.
Treatments, specifically those for pests, are often based on action thresholds. This threshold marks the line between an acceptable number of pests or amount of damage and the point where control actions are taken. In agricultural production, there are many well-documented thresholds based on economic loss. These thresholds are generally measured in percent of crop loss or number of individual pests. We recommend that you research your individual field for specific threshold information related to the pests and diseases that affect your crop.
There are not many well-documented action thresholds available for landscape plants. The action threshold in this case may be determined by your own experience with the plants and pests in your area. When balancing client expectations in the landscape, aesthetic injury threshold is used more often than a threshold based on monetary loss. The threshold is determined by the point at which most users of the landscape would find the damage to be intolerable. Again, this is based on the professional’s experience.
Information Is Power In Crop Protection
There are a number of critical pieces of information that should be collected during monitoring activities. A monitoring checklist should be completed by the professional and kept on record by the company. A monitoring report is generally printed on company letterhead and provided to the client. Subsequent monitoring visits should be documented as well. The following is a suggested format that may be useful for professionals who seek to document monitoring activities. This document should be kept by the company but can be modified to serve as a report to clients and utilized for future monitoring visits.
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Initial Monitoring Record Company Professional Date of Visit
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Significant Plants on Site:
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| Treatments Made During Visit
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Additional Plants on Site:
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Samples Taken During Visit and Location(s):
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Recommendations to be made to the client:
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| Other information important to the health of this site:
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This suggested record-keeping form was adapted from the Plant Health Care technique (Harris, Clark, & Matheny, 1999; Smith et al 2002).
Resources
There are a number of resources that are available to aid in identification of different pests, diseases, and disorders in the landscape. Please click on each link to become familiar with these resources.
- Your Local County Extension Office (http://solutionsforyourlife.ufl.edu/map/) – Please scroll down on this page to find county and local research centers’ website addresses and contact information, and you can click on your county to find directions, a phone number, and office hours for your local Extension office. County Extension staff are great resources for problem identification.
- The University of Florida Plant Diagnostic Network (http://fpdn.ifas.ufl.edu/) serves the state and region through diagnosis of commercial, homeowner, and extension plant disease samples submitted to the laboratory for turf, ornamentals, fruits and vegetables, and other plants. Please click on the Homestead, Gulf Coast, or Gainesville/Main Campus link (whichever is closest to you) and locate the plant submission form you would use.
- The UF / IFAS Extension Soil Testing Laboratory in Gainesville (http://soilslab.ifas.ufl.edu/ESTL%20Home.asp) offers a variety of tests for mineral soils, container media and irrigation water. Information about these tests can be obtained on this website or by contacting your local County Extension Office. Please click on the “ESTL tests” to see the numerous diagnostic tests available to you. You will see that there are tests available for soil and water for landscapes, container nurseries, and specific agricultural crops.
- Florida Nematode Assay: http://edis.ifas.ufl.edu/pdffiles/SR/SR01100.pdf
- University of Florida Insect Identification Service: http://edis.ifas.ufl.edu/pdffiles/SR/SR01000.pdf
Conclusion
This article discussed the meaning, and importance of monitoring, plant health care (PHC), and action thresholds. To summarize, monitoring is an important component of a plant health care program, which is important to the health of agricultural operations, nursery production, and landscape management. Appropriate monitoring includes the aspects of positive identification, recordkeeping, developing strategies, determining the cause of problems and devising methods to prevent them in the future, and taking actions based on thresholds. There are a number of resources available to professionals for assistance with plant identification, insect and disease diagnosis, and soil testing.
Credits
- Florida Department of Environmental Protection. (2008). Best Management Practices for Protection of Water Resources in Florida. Available at: http://ffl.ifas.ufl.edu/pdf/GIBMP_Manual_WEB_2_17_11.pdf
- Harris, R.W., Clark, J.R., & Matheny, N.P. (1999). Arboriculture: Integrated Management of landscape trees, shrubs, and vines.
- Leppla, N.C., Green, T.A., Sonke, D.J., and Larson, B.C. (2004). Increasing adoption of reduced risk practices in the production of woody ornamentals. Final Report for the Environmental Protection Agency: Grant Agreement Number 97464302. University of Florida IFAS. Available at: http://ipm.ifas.ufl.edu/pdf/woody_ornamentals_05.pdf
- Smith M.A.L., Endress, A.G., Smith, G.R., Lloyd, J.E., Neely, R.D., Stutman, R.K., Ball, J.J., Coder, K.D., Wadley, T.L. (2002). A guide to the plant health care management system. 3rd Edition.
- University of Florida IFAS. IPM Florida. Available at: http://ipm.ifas.ufl.edu/
- Washington State University Urban IPM and Pesticide Safety Education Program. Using IPM in the Landscape. Available at: http://pep.wsu.edu/pdf/factsheets/ipmdecisionmaking.pdf
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