Module 1
Field History
Preparing for field assessment
Determine your survey approach
Extension agent Wayne
Cooley, ARS agronomist
Randy Anderson, and farmer
Gilbert Lindstrom
Photo by Scott Bauer
Field History
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Ask questions!
Get records, if possible
Make general observations
Learn to detect what might
be causing the problem
Field History
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Previous crop
Chemical history
Planting date
Variety and seed lot
Tillage methods
Soil amendments
Weather
Movement of soil into
field
Preparation for Field
Assessment
• Successful diagnosis starts with good
preparation
• Keep some useful tools around, and
think about the history (as you know
it) and nature of the concern
PreparationNDSU
forExtension
Field
specialists
trained IPM survey scouts
Assessment
in late May
• Notepad, recordkeeping form or handheld computers
New tools of the survey:
• Proper
clothing,
forand
Portable
computers
Global positioning units.
safety
• Always observe
appropriate re-entry
intervals (REI)
Preparation for Field Assessment
• Hand lenses magnify tiny
features that may be
useful
• Common magnifications
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4X
10X
16X
20X
Aphid Magnification
English grain aphid
Rust magnification example
Barley rust photo: Vernyl Pederson
Preparation for Field Assessment
Other useful tools
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Trowel
Knife
Plastic baggies
Vial – with alcohol for
insects
• Camera – digital/35 mm
• Bucket
• Sweep net
Determine Survey Approach
• Surveying (or scouting) requires
consideration of approach or pattern of
travel
• Specific concerns may dictate a certain
type of scouting method
• Regardless of method – the goal is to get
a representative sample
Determine Survey Approach
• Scouting routes may be modified by:
– topography
– soil types
– irrigation channeling
– field entrances
• Regardless of the approach, the goal is to
get a representative idea of the problems
Determine Survey Approach
• Scouting in a W or Z pattern for pests or
problems distributed uniformly over the
field
Examples: Foliar diseases later in season;
European corn borer; Pesticide damage
Determine Survey Approach
• Scouting or sampling in
areas where pests or
damage may be
concentrated
Examples:
root rots associated
with low areas or
in patches;
cutworms in low,
cool areas;
white grubs
Determine Survey Approach
Pests or damage associated with field borders
or waterways
Examples: grasshoppers, chinch bug
Determine Survey Approach
Number of sites to visit in the field
Sampling or surveying usually is done at 5 sites per 40 to 50 acres