9/21/2014
Pest Recert InfoSession:
The First Lines of Defense - Sanitation & Scouting
States recognizing the session:Alabama Florida
GeorgiaNorth Carolina Ohio
South CarolinaTexas Virginia
The First Lines of Defense ‐Sanitation & Scouting
Carlos E. Bográn, PhD
Technical Manager, OHP Inc.
#TK132
Where can pathogens survive?
Plants
Soil from outside Under benches
Contaminated water
Contaminated water
Insects
Soil-media
Old crop
Sanitation & Scouting are part of IPM
IPM: Strategy to avoid or prevent pest damage with minimum adverse impact to human health, environment and non‐target organisms
Focuses on tactics to avoid or minimize damage before it occurs, integrating previous knowledgewith pest monitoring information and the expertise of the practitioner…
• Ecosystem science, community ecology, population and organismal biology and ecology, genetics…
• Of plants, herbivores and their predators, opportunistic‐ and invasive species, etc.
• General principles apply to all species including ‘noxious’ common pests and pathogens
• Used in developing appropriate pest/disease/weed management tools
Integrated Pest Management, a Science Based Approach
Key scientific concepts in IPM• Crop yields are often limited by herbivores, plant pathogens, weeds…
• Most plants tolerate a minimum level of injury before damage occurs; this level varies greatly
• Populations are affected by environmental conditions and by the populations of other species, natural enemies and competitors
• Impact of mortality factors often varies with pest/pathogen population density (# per area)
• Pesticides are essential management tools and should be used to prevent or minimize damage
Typical Population Growth Curve
Nu
mb
er o
f in
sect
s
Time (weeks)
No Damage Damage
Treatment at low pest density is more effective and prevents damage
Treatment at low pest density is more effective and prevents damage
Disease Epidemiology
• Types of epidemics: monocyclic and polycyclic
• Monocyclic: Polycyclic:
x = QRt x = X0ert
• Q = initial inoculum, R = rate of infection, t = time
• X0= initial disease incidence, r = rate of infection, t = time
Monocyclic Epidemic Polycyclic Epidemic
x
tX0
x
t
x = QRt x = X0ert
Modeling Disease Progress Epidemiology & Disease Management
• Objective is to reduce:1. Initial inoculum
2. Infection rate
3. Duration of epidemic
• Success involves combination of tactics:• avoidance, exclusion, eradication (aka
sanitation)
• protection, resistance and therapy (aka good cultural practices)
Sources of Inoculum
• The watch kept plants and pest populations with the purpose of making a decision
• A pest survey is a detailed collection of population/plant injury information at a given time in a given area
• Done via quantitative sampling
Scouting for trouble…
Crop Monitoring (Scouting)
• Regular, systematic inspection of each crop and growing area
– Crop uniformity
– Symptoms of (disease) plant stress, abnormal growth, coloration
– Presence of insects and mites
– Pattern of infection/infestation (mapping)
Sanitation is a Key IPM Component• Prevent development of
pest/disease/weed problems
• Regularly check plant health status: detection and monitoring
• Accurately diagnose crop issues; use good information to make good treatment decisions
• Use only effective (proven) tools
Common Sanitation Oversights
1. Lack of good water management practices, irrigation, drainage, contamination
2. Weeds in and around the greenhouse/nursery
3. Lack of inspection of incoming/young plant material
4. Taking cuttings from infested/infected mother plants
5. Pet plants, left behind in the nursery or greenhouse
Water management practices affect crop susceptibility
• Water quantity:
– Volume
– Frequency
• Water quality:
– Biological contaminants
– pH and alkalinity
– Dissolved minerals
– Suspended soil particles
Water Impacts cont:• Plant growth and health
– Growth rate/ vigorous new growth
– Water stress
• Insect, weed and pathogen abundance and distribution
– Habitat, mortality and survivorship
• Pest/disease/weed control efficiency
– Physical/mechanical control of organisms
– Chemical control (water pH)
Eliminate algae growing under benches or in water tanks
Extremes of moistureToo little water:• Stunting, wilt, leaf scorch, senescence, death
Too much water:• Similar symptoms• Suffocates roots,
inhibits oxygen uptake
Extremes of moisture cont.
• Excess water promotes
– Growth of anaerobic microbes and their toxic metabolites
• Problem is worse at elevated temperatures (increased oxygen demands)
• Other symptoms:
– Edema: callus‐like cells on epidermis
– Adventitious roots
Edema and adventitious roots are symptoms of excess moisture
Avoiding the Top Ten Mistakes
1. Lack of good water management practices, drainage
2. Weeds in and around the greenhouse/nursery
3. Lack of inspection of incoming/young plant material
4. Taking cuttings from infested/infected mother plants
5. Pet plants, left behind in the nursery or greenhouse
Cleaning and Maintenance
Elimination of alternate hosts (plants)
• Keep greenhouse and surrounding areas free of weeds
• Discard ‘residual’ plants (those that will not be sold) and those from a previous crop
http://edis.ifas.ufl.edu/HS169
http://elainemeinelsupkis.typepad.com/free_trade/images/greenhouse_weeds.jpg
C. Gilliam, Auburn University
Bark Pile Contamination
C. Gilliam, Auburn University
Insect Screening
1.Screening reduces air flow and may damage fans
To avoid entry of flying insects
National Greenhouse Manufacturers Association:http://www.ngma.com/standardpdf/InsectScreen.pdf
2.General rule: area of screened box should be at least twice the area to cover
SELECTING THE TYPE OF SCREEN TO INSTALL
INSECT TO EXCLUDE
INSECT SIZE‐ IN. (microns)
SCREEN TYPE
HOLE SIZE‐ IN. (microns)
Leaf miner0.025(640)
Vector‐virus0.0105 x 0.0322 (266 x 818)
Aphids0.013(340)
Vector‐virus0.0105 x 0.0322
(266 x 818)
Whitefly0.018(462)
Vector‐virus0.0105 x 0.0322 (266 x 818)
Thrips0.0075(192)
No thrips0.0059 x 0.0059 (150 x 150)
Avoiding the Top Ten Mistakes
1. Lack of good water management practices, drainage
2. Weeds in and around the greenhouse/nursery
3. Lack of inspection of incoming/young plant material
4. Taking cuttings from infested/infected mother plants
5. Pet plants, left behind in the nursery or greenhouse
Plug/seeding inspection at arrival
• Open boxes immediately and carefully check plants
• Symptoms?
• Return, dispose or treat plants immediately
Avoiding the Top Ten Mistakes
1. Lack of good water management practices, drainage
2. Weeds in and around the greenhouse/nursery
3. Lack of inspection of incoming/young plant material
4. Taking cuttings from infested/infected mother plants
5. Pet plants, left behind in the nursery or greenhouse
Mother plant/cuttings health
• Garbage in, garbage out
• Start program on mother crop
• Minimize handling stress
• May treat during propagation to increase cutting survival
• Quality control before production
6. Continuous cropping of the same species in the same range
7. Lack of tool/equipment disinfection
8. Contaminated irrigation water
9. Handling of ‘shrinkage’ (left‐over, unsalable plant material) and plant debris
10. Lack of employee awareness on impact of sanitation
Avoiding the Top Ten Mistakes cont.
Chemical Control?
6. Continuous cropping of the same species in the same range
7. Lack of tool/equipment disinfection
8. Contaminated irrigation water
9. Handling of ‘shrinkage’ (left‐over, unsalable plant material) and plant debris
10. Lack of employee awareness on impact of sanitation
Avoiding the Top Ten Mistakes cont.
Tool cleaning and disinfection
‐ Wash with water and soap to loosen residues
‐ Dip tools in disinfectant solution
‐ Hang or store in clean container
‐ Steam or dry heat; 85 – 95 ºC 30 min.
‐ Ethanol 70%; dip and air dry
‐ Hydrogen Dioxide (Zerotol); dip, brush
‐ Quaternary Ammonium (Green‐shield, Physan 20, Triathlon); dip
6. Continuous cropping of the same species in the same range
7. Lack of tool/equipment disinfection
8. Contaminated irrigation water
9. Handling of ‘shrinkage’ (left‐over, unsalable plant material) and plant debris
10. Lack of employee awareness on impact of sanitation
Avoiding the Top Ten Mistakes cont.
Water treatment to remove pathogens
www.ch2o.comhttp://watereducationalliance.org
6. Continuous cropping of the same species in the same range
7. Lack of tool/equipment disinfection
8. Contaminated irrigation water
9. Handling of ‘shrinkage’ (left‐over, unsalable plant material) and plant debris
10. Lack of employee awareness on impact of sanitation
Avoiding the Top Ten Mistakes cont.
Too late for controlToo late for control
Sanitation practices cont.
• Do not accumulate plant debris in the greenhouse/nursery
• Dispose of old plants that will not sale, leftover or pet plants
• Keep dumpsters and water tanks covered to avoid contamination
6. Continuous cropping of the same species in the same range
7. Lack of tool/equipment disinfection
8. Contaminated irrigation water
9. Handling of ‘shrinkage’ (left‐over, unsalable plant material) and plant debris
10. Lack of employee awareness on impact of sanitation
Avoiding the Top Ten Mistakes cont.
Personal hygiene, tobacco use, etc.
http://carrolltonac.com/washing%20hands.jpg
TMV (Cymbidium hybrid) – M.Erasmus
Why Monitor?
• Early detection facilitates control and reduces costs
• Determine severity (abundance and distribution)
• ID areas requiring immediate action
• Evaluate control effectiveness
• Learn from success and failure
57%
43%30%
25%
Scientific Basis: Insect Ecology
• Insects, mites, pathogens thrive and reproduce within populations
• All populations have unique characteristics: population density, dispersion, growth rate, age structure
• Understanding the characteristics of pest populations facilitates pest management
Population Density
• Number of individuals per area/volume (absolute; high cost)
• Number of individuals per sample (relative; lower cost; for decision making)
• Population density index: % damage, % defoliation, (sometimes more practical)
Population Dispersion
• Spatial arrangement of individuals in area
• Depends on insect behavior and species reproductive strategy (i.e. eagles vs. wolves)
• Three basic types of dispersion: uniform (not common), random (by chance) and patchy (aggregated; most common) uniformpatchyrandom
5 4 0 5 3
3 1 3 3 7
3 5 2 3 6
4 4 2 3 4
2 7 1 5 0
20 20
20
20 20
100
Dispersion example
X = 4.0S2 = 4.58
X = 4.0S2 = 66.7
X = 4.0S2 = 400.0
A B C
Estimating Pest Density
Mean or average = sum of counts in all samples divided by the total number of samples
Variance describes variability of samples relative to the mean or average
Developing a Monitoring Program
• Start simple (an easy crop or small area)
• Plan ahead: what, how, who will perform
• Designate sampling units‐ areas of observation
• Careful inspection; use sampling tools
• Adjust scouting frequency based on growing season, crop value and pest risk
• Learn how and where to find key pests and disease symptoms
• Keep records; modify program as needed
Sampling and Sampling Units
• Estimate population density in the crop: counts or other relative measures
• Identify sampling unit: proportion of crop from which counts will be taken
• Pest density usually expressed in area of crop (i.e. number of pests per block or bench)
• Resulting pest density estimate used to compare numbers in time and between areas
Turning leaves Sticky traps Beat sheet
• Many pests only in underside
• 3-10 minutes / 1,000 ft2?
• Stratified for most pests
• Many pests only in underside
• 3-10 minutes / 1,000 ft2?
• Stratified for most pests
• Flying insects• Regular pattern
for specific time
• At least one trap / 10,000 ft2
• Placement important
• Flying insects• Regular pattern
for specific time
• At least one trap / 10,000 ft2
• Placement important
• To dislodge insects
• 5 gal. bucket can be used
• Compare #’s between sampling dates
• To dislodge insects
• 5 gal. bucket can be used
• Compare #’s between sampling dates
Selecting plants for inspection:
• Randomly select plants, for unexpected problems
• Target sample for anticipated problems
• IPM approach: combine random and target selection of plants to sample
• Need to be consistent and systematic (to minimize risk of missing something important)
Presence‐absence sampling:
• Alternative to insect counts (infested: yes/no)
• Percentage of samples infested
• Compare infestation rates among sampling areas or sampling dates
• Most useful when presence‐absence sampling is correlated with average pest density
Economic thresholds for pest management Records: data: information
• It is critical to collect pest/disease data
• Most critical are estimates of infestation levels during the growing season
• Include specific information on crops, weather conditions, pest control history including products used
• Map growing areas, note key features of terrain that may influence pest (doors, water sources, wind direction)
Thank you