Introduction to Integrated Pest Management (IPM)

Key points of IPM• Integration

– Harmonious use of multiple methods to control single pests or pest complexes

• Pest– An organism detrimental to humans,

including: invertebrates, vertebrates, weeds, and pathogens

• Management– Decisions based on ecological principles and

economic and social considerations

Key points of IPM

• IPM is a multidisciplinary endeavor• Agronomy (crop and soil science)• Entomology (insects: pests and beneficial)• Plant pathology (plant diseases)• Economics (decision-making)• Agricultural Engineering (machinery, grain

handling, etc.)• Climatology (weather trends and effects)

History

• ~2500 BC: The element sulfur was found to help control mite and insect populations

• ~1500 AD to present: some plants found to generate insecticidal—and more recently—herbicidal compounds– Pyrethrum (pyrethrin - insecticidal)– The Neem tree (NEEM - insecticidal) – Bottlebrush plant, Callistemon sp. (herbicide

Callisto)

History

• Late 1800s: inorganic compounds used for insect and fungal organism control, including:– Paris green (copper acetoarsenate)– Bordeaux mix (copper sulfate and hydrated lime) – Lead arsenate– Creosote (coal tar derivative)– Sodium hypochlorite solutions (bleach)

• 1939 (dawn of the modern insecticide era): DDT recognized as an effective insect control

• Late 1940s (post WWII): the advent of “chemical” pesticides including 2,4-D

• 1948 Warfarin™ registered as a rodenticide (and later -in the early 1950s- as an anticoagulant in human medicine)

History

History

• 1962: Silent Spring published•

• 1967: the term “IPM” first used

• 1970: the United States Environmental Protection Agency (EPA) was founded

• 1979: the Iowa State University IPM program began

• 1993: call for 75% of U.S. crop acreage grown under IPM principles (by 2000)

History

• 1996: Roundup-ready® soybeans introduced in the U.S. By 2005, 87% of commercial U.S. soybean acres were Roundup-ready® varieties

• In 1998 Roundup-ready® corn introduced in the U.S.

• 2000s: U.S. farmers now apply over 1.2 billion pounds of pesticides annually

• Today: with increasing knowledge of pests, crops, and improving technologies, field-specific management is possible

History

IPM

1. What is “normal?”- Is it really a problem?

2. What is the problem?• Proper identification

is critical; that is why it is the first step.

IPM

3. How and what does the pest attack?• Only the plant of interest affected?• Parts of plant affected?• Patterns in field?

4. How many pests are there? • Is it too early or too late to

control? • Management must be at the

correct time to maximize effectiveness.

IPM

5. Determine an action threshold • How many pests are too many? • Economic, health, and aesthetic threshold

Daylily plants with aphids

6. Choose appropriate management tactics• For many pests, there are several management

options to consider.

7. Review your work: Was the management

effective? • Did actions do what you wanted? • Was the method itself satisfactory? • Were there any unintended side effects?• What will be done in the future for this pest

situation?

IPM

Three important components

• Economic injury level– Lowest population density that will cause

economic damage• Economic threshold

– Population size large enough to trigger an action to prevent an increasing pest population from reaching the economic injury level

• General equilibrium position– Average density of a population over time

Costs vs. Benefits of a Practice

Costs • Product cost• Fuel • Labor• Marketing options• May increase crop

damage from secondary pests

Spider mite damage to soybean

Costs vs. Benefits of a Practice

Costs • Product cost• Fuel • Labor• Marketing options• Predisposition to

secondary pests

Benefits• Yield (economic)• Quality (economic)• Appearance (aesthetics)• Human/livestock health• Legal issues• Acceptance of resultant

commodity by end users• Ease of mind

What has changed in agriculture?

• Fewer farm operators, yet the same acreage• Fewer ag retailers, yet the same acreage• Increased decision-making by someone other

than the grower or pesticide applicator• Rapidly emerging crop alternatives and

demands (biofuels, special-purpose crops)• Increased community and regulatory pressure• Increased options (products/formulations)• Greater concern about product availability

and future costs

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Scouting Fields

Overview

1. Do your homework

2. Basics of scouting

3. Help! I still don’t know

Know what “healthy” looks like

• What does a normal plant look like?– Above ground– Below ground– On the inside

• A sick plant is less productive and often gives indicators (e.g., color or growth) called “symptoms.”

• If you know what a healthy plant looks like, you can recognize when there is a problem.

Know common problems

Know common problems

Know common problems THIS year

• Keep up on the news– Local agribusiness– Internet– Print media– Word of mouth

V6 VTV12

Anthracnose leaf blight

Gray leaf spot (GLS)

Common rust

EyespotSeedling blights

R2VT R4 R6

Anthracnose top dieback

Stalk rots;Ear rots

GLS; Common rust; Northern corn leaf blight

Timeline for common corn diseases

Corn growth stage:

Know common problems for each time of year

Basics of scouting

• Accurately estimate crop plant health, stand, growth stage and populations of any pests present

• Pest identification and/or diagnosis of the cause of crop injury

• Gather equipment • Contact grower

Let them know when you are coming Ask if there are any special instructions Spend time with them

• Collect information about the field/season – learn the field history

First steps of scouting

Map fields• Aerial photographs• Map from plat book or Google™ Maps

Collect information

Collect information

Map fields• Soil map (printed soil survey or download)

Collect information

Consider recent weather• Environmental stresses may damage soybean

and corn directly or make them more susceptible to some diseases.

Collect background information for the field

• Previous crops, adjacent crop and non-crop areas• Chemicals used on or near the crop including

herbicides, fertilizers, fungicides and insecticides; indicate when applied, how applied, rate of application, weather conditions during and following application

• Planting date, depth, and seedbed conditions• Hybrid/variety information, including disease

resistance• Current soil test information (e.g., soil fertility, pH)• Soil moisture and compaction

Collect information

1. Look at the BIG picture (field level)

2. Look at the little picture (plant level)

3. Record information

Basics of scouting

i. Is the problem scattered randomly through the field or occurring in a pattern?

ii. Is the problem more prevalent along a fence, field edge, entrance of a field or along a waterway?

iii. Is the problem in the affected area more severe in certain soil types, low areas or on exposed slopes?

iv. Does the pattern correspond to tillage, planting, spraying, harvesting or other field activities?

LOOK FOR PATTERNS

1. Look at the BIG picture (field)

Random Aggregated

Look for patterns

T. Allen, Miss. St.

Slope

Look for patterns

AggregatedAggregated

© Marlin E. Rice

Look for patterns

RepeatedEquipment can often cause patterns that are repeated across fields.

For example, spray overlap every time the booms overlapped, compacted areas every "x" rows from combine tires the prior fall, etc..

Scouting patterns

Transect Zig-zag Diamond

Check individual plants for symptoms and signs

i. Compare damaged plants with healthy plants.

ii. Check the entire plant and environment around it, including leaves, stems, roots, internal tissues, soil, pests not directly on plant, competition, etc.

iii. A small hand lens, a pocket knife, a trowel, a shovel and the field guides are valuable tools.

2. Look at the little picture (plant)

Check individual plants

Look at more than one plant

Aim to assess a minimum of 50-100 plants

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i. Check the prevalence and severity of the problem.• How often does the problem show up?• How damaging is the problem?

3. Record information

Assessment methods

• Incidence = % plants diseased

• Severity = % tissue diseased

Foliar disease severity (%)

1 % 2 %

5 % 10 %

Gray leaf spot

Stalk disease severity value