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Competency Area 1: Integrated Pest management (IPM)

PO 4. Recognize the importance of using appropriate sampling methods to determine presence or absence, and to estimate population density of a species. Know the components of proper sampling including method, location, timing, and sample size.

Scientific sampling techniques vary by crop and pest type. Methods to assess the damage potential of important common pests can generally be found in state crop and IPM guides. Sampling techniques and protocols strive to collect information representative of the whole field condition on which to make management decisions. Correct sampling helps eliminate the guesswork in pest control by providing a means to quantify the pest problem. Use sampling knowledge and information on pest and crop biology to make better management decisions. Note: Local conditions may affect crop and pest biology. To most effectively use IPM guidelines, use the sampling methods and threshold guidelines recommended by your state. (For NY field crop IPM: or

Common methods for sampling:
Visual Inspection- for insects, diseases, weeds, vertebrate or other plant damage. Assessments made while walking throughout the field. Data are generally recorded as the number of individuals per plant or plant part or percentage of plants or area affected. Weed assessments include species identification, type (annual, perennial, grass, broadleaf, etc.), and the relative abundance of important species in the field. Weed populations can be evaluated using the rating scheme provided in the weed assessment section.
Insect Sampling:
• Sweep net or beat cloths – For mobile insects such as potato leafhopper sampling protocols call for
using a 15 inch diameter sweep net. Samples are taken a numerous locations within the field.
Assessments are made by counting the number of individuals collected in the net per “X” number of
sweeps. Beat cloths are another method of collecting information on less mobile insects in row
crops, such as spider mites and aphids. The beat cloth is used as a means to collect insects shaken
from plants in a sample area such as a square foot. The number of individuals collected per unit
area is compared to recommended guidelines.
• Trapping – Several types of trapping devices are used in collection of insect information.
            • Light traps – used to determine relative abundance of insects in a defined region. Information on the number of adults caught in the trap over time is used to help predict potential pest outbreaks.
            • Sticky traps – Used to collect small flying insects such as aphids, leafhoppers, flies, and beetles. Relative abundance and type of insect collected is recorded.
            • Pheromone traps – chemical attractant traps used to determine if a particular species is in the area. Also used to detect initial flights of insects such as European corn borer and the relative abundance of insects like western corn rootworm.

Identification, sampling and management guidelines for specific insects and their damage can be found in state crop and IPM guidelines. Information on specific sampling strategies for specific pests on crop of interest (in New York State) can be found in resources such as the Cornell Guide to Integrated Field Crop Management or the New York State IPM website (

Disease Sampling
As different diseases are favored by different environmental conditions, scout for diseases throughout the entire growing season in conjunction with other scouting activities. Diseases may become more obvious during certain times of crop development such as crop emergence, or during times of stress (e.g., drought or flood), and pre- or post-harvest. Look for areas of stunted, yellow, discolored, wilted, contorted or dead plants.
Symptoms of different diseases often appear similar and can at times be confused with other ailments such as nutritional deficiencies and abiotic problems. If a problem cannot be diagnosed in the field, dig up several plants that show typical symptoms. For many diseases it is important to include above and below ground plant parts when submitting samples for diagnosis.
Estimate the percentage of plants affected by the disease throughout the field. Record information concerning particular problem areas, noting location, size of area affected, drainage pattern, etc.

Weed Sampling
Scout for weeds in the spring and fall. As always, take care to obtain a representative sample of weed conditions throughout the field, although weed infestations may not be uniform across the entire field. Document the weed type rather than taking detailed counts of weed species.
Observe at least five random areas of a forty acre field; divide larger fields into two equal parts for scouting. Base these divisions on previous field history, soil type, topography, or other factors that might affect weed populations.
Scout for weeds in conjunction with other monitoring activities. See the comments above for “Visual Inspection”. Record weed type (annual, biennial, perennial, grass, sedge, and broadleaf) and relative importance from all parts of the field. Note any areas with significant weed problems. Map weed locations on the scouting form.
Check special terrain features such as droughty slopes, poorly drained areas, field borders, and fence rows for weeds. These areas can be major sources of weed contamination and differ significantly from the rest of the field. After rating the weeds, rank the most prevalent weed species in each field in order of severity.