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PLANTS, PESTS AND SOILSPECIALTY CROP INTEGRATED PEST MANAGEMENT
WEBINAR SERIES PART 1
AMY KOEHLERSPECIALTY CROP INSTRUCTOR AND TECHNICIAN
Sponsors
Some Information provided by University of Minnisota Extension: Jeffrey Hahn, Extension entomologist; Suzanne Burkness, College of Food, Agricultural & Natural Resource Sciences; Dave Ragsdale and Edward Radcliffe
A Pest Defined• Technically, any organism (bacteria, fungi, plant,
animal) that has a negative effect on human health or economics (food).
• Realistically, any organism we don’t want around (factors in convenience and esthetics).
Philosophies of Pest Control
• Chemical Technology• Use of chemicals to kill large
numbers of the pest• Short-term protection• Environmental and health
consequences
• Ecological Pest Management• Control based on pest life cycle
and ecology• Control agent may be an
organism or chemical (more on next slide)
• Specific to pest and/or manipulate a part of the ecosystem
• Emphasizes protection from pest
Pesticides (Biocides)• Insecticides (Insects)• Herbicides (not just the weedy plants)• Rodenticides (mammalicides)• Fungicides (mildews and rusts)• Acaricides (ticks and mites)• Bacteriocide (e.g. antibiotic)
The Early Years of Chemical Pest Control
• First-generation pesticides (inorganic)• First attempt at chemical
technology• Included heavy metals such as
arsenic, copper and lead.• Toxic to humans and agricultural
plants.• Pests developed resistance.
Pesticide “Improvements”
(?)
• Second-generation pesticides • Organic chemical
(organochlorines).• Used after WWII (presently in
developing countries)• Synthesis begins with petroleum
(“oil”)• Mechanism of actions often
unknown.• Bioaccumulation &
Biomagnification.• Toxic to animals (humans) and
agricultural plants.• Pests developed resistance.
Smarter Pesticides (?)
• Third-generation Pesticides• Organophosphates and carbamates• Less persistent in environment (good
deal)• Acutely potent nerve toxins• More lethal in low dose than
organochlorines
• Fourth-generation Pesticides• Endocrine disruptors (hormonal chaos)• Target a critical life cycle stage of
insects.• Not direct killers per say.• Reduce reproduction (fertility) of
population.
Pesticide Use in the United States
Chemical Technology
Problems
Development of resistance by
pests
Resurgences (pest comes
back stronger)
Secondary pest outbreaks
(different pest)
Adverse human health effects
Adverse environmental health effects
Resistance to Pesticides• Chemical pesticides lose
effectiveness• Resistant pest populations produce
next generations
History of Pesticide
Resistance
WHEN WILL IT END?
Human Health Effects• Acute: high dose, short-term response,
rapid onset (headache, nausea, vomiting, respiratory failure, death). Agricultural workers suffer acute poisoning during pesticide application.
• Cronic: low-dose, long-term exposure, outcome takes many years before noticed (cancer, dermatitis, neurological disorder, birth defects, sterility, endocrine system disruption, immune system depression). Neighborhoods downwind of agricultural use; farm families; the innocent.
Environmental Effects• Bioconcentration:
• Movement against a concentration gradient; typically fat soluble.
• Biomagnification:• Movement through the food
chain to higher trophic levels; typically persistent.
• Bioaccumulation:• Combined effect of both;
chemicals are typically fat soluble and persistent.
The DDT Case Study• 1938; dichloro-diphenyltrichloroethane (DDT)• Extremely toxic to insects, but seemed nontoxic to humans
and other mammals.• Cheap.• Broad-spectrum and persistent• Effective for disease prevention (typhus fever, malaria) • Expanded agricultural production• Paul Muller awarded Nobel prize in 1948
BIOACCUMULATION &
BIOMAGNIFICATION
Natural Pest Control•Cultural control•Control by natural enemies•Genetic control•Natural chemical control
Insect Life Cycle
Cultural ControlGet rid of the
alternative host!
Control by Natural Enemies
Some Examples of
Insect Food Chains
Genetic Control
• Plants or animals are bred to be resistant to the attack of pests.
• Chemical barriers.• Physical barriers.
• Introduction of genes into crops from other species: transgenic crops (Bt)
• Sterile males are released into pest population.
Natural Chemical Control
• Manipulation of pests’ hormones or pheromones to disrupt the life cycle.
• Japanese beetle trap.
INTEGRATED PEST MANAGEMENT!
IPM Defined:• "IPM is a sustainable approach to managing pests by combining
biological, cultural, physical and chemical tools in a way that minimizes economic, health, and environmental risks."
Integrated Pest Management(IPM)• An approach to controlling pest populations using
all suitable methods - chemical and ecological.
• The goal is to brings about long-term management of pest populations that also have minimal environmental impact
Why IPM?• Collapse of Control Systems.• Pesticide resistance.• Loss of pesticide registrations.• Health risks associated with pesticides
for agricultural workers and consumers.• Loss of natural enemies brought on new
pest outbreaks.
Basic IPM
Monitoring or Scouting
Pest Identification
Threshold and Action Levels
Tactics: Cultural, Mechanical, Physical, Biological, and Chemical
Evaluation
IPM
Pest management,
not eradication, is the goal.
Manage pests below the economic threshold.
Thresholds and Action
Levels
Problems:
Growers want to avoid risks; especially with high value crops.
Once the threshold level is reached, the probability of partial or total crop loss is high.
Economic Thresholds
• Thresholds should be quantitative and grower driven.• For example, thresholds could be based on the
average number of pests per trap each week. • The percent of plants or leaves found to be
damaged or infested during visual inspection. • The number of pests dislodged per shake sample.
EIL
ETAveragedensity
Time
80
70
60
50
40
30
20
10
0
Economic Threshold
Apply controls
Avoid exceeding economicinjury level
Economic Thresholds
Vary depending upon the crop.
Bacterial Leaf Spot on Poinsettia: Devastating!
Bacterial Leaf Spot on Greenhouse Tomatoes:
Not such a big deal. Why?
Insects & diseases on ornamental crops grown in nurseries:
Big deal? Yes or no?
INTRO TO SOILS AND EFFECTS ON PLANT
HEALTH AND GROWTH
What is Soil?
Provides air, water and nutrients to plants
Soil provides mechanical support to plants
Consists of weathered materials, decaying organic matter, air and water
What is soil?Defined as:
• Mineral & Organic material that supports plant growth on the earth’s surface
• Mixture of particles of rock, organic materials, living forms, air, water
What soil resources help in supporting life?
Oxygen: needed for adequate root growth
Temperature: soil absorbs heat from the sun – loses
heat to atmosphere (plant growth and seed
germination)
Water: plant growth Carbon: organic matter
Nutrients: minerals
Soil
• Mineral• Organic Matter• Air• Water
Components of Soil
42
Mineral Matter: about 45% of soil (partially decomposed rock material (sand, silt,
clay)
Organic Matter: about 5% of soil
(partially decomposed plant &
animal matter)
Air: about 25% of soil (constant fluctuation as soil is dry and wet)
Water: about 25% of soil
44
Living Organisms in the soil• Forms of life:
• Earthworms• Insects• Bacteria• Fungi• Other organisms
Growth FactorsWhat do plants need to grow?
LIGHT WATER NUTRIENTS OXYGEN CARBON DIOXIDE
TEMPERATURE
Soil Fertility• There are 17 known elements that are essential
for plant growth• Plants require nutrients that are not created
through photosynthesis • H, O, C Plants get from air and water
• Macronutrients• N, P, K High amounts• Ca, Mg, S Lesser amounts
• Micronutrients• iron (Fe), boron (B), chlorine (Cl),
• manganese (Mn), zinc (Zn), copper (Cu), Small amounts• molybdenum (Mo), nickel (Ni)
Plant Nutrients
• Can be added to soil through commercial fertilizer (i.e., 12-12-12), animal manure or compost
• To know the amounts to apply, you need a soil test
• Excesses and deficiencies can cause poor plant growth or death
Nitrogen• Most of soil nitrogen is in the form of organic matter
• Promotes growth and color
• Excess causes excessive growth, weak stems
Nitrogen Deficiency• Growth dwarfed and thin: overall plant is light
green in color and turning yellow in the late season
Phosphorus
• Primary source: specific minerals and OM
• Promotes seed development, reproduction, cell division
• Enhances root development and water uptake by the roots
• Excess may lead to deficiencies in other nutrients
Phosphorus (P)• The first symptoms are downward
curling of the leaf
• The interveinal tissue becomes a paler green and eventually dies
• There may be a marginal scorch on the older leaves.
Potassium• Source in soil: minerals• Increases winter hardiness, reduces diseases,
important in ripening of fruits and vegetables
• Leaves are smaller, dark olive green and have a dull appearance.
• There is a tendency for the leaves to curl downward and the leaf petioles to become darker red.
• Brown spots develop interveinally on the under surface of the leaves.
Potassium (K)
What’s pH all about?
• pH is determined by soil type• Can effect plant growth and nutrient
availability• Different plants have different soil pH
requirements• Can be adjusted through soil amendments
Soil Fertility - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/Soil-pH-and-Nutrient-Availability_fig3_262798335 [accessed 5 May, 2020]
https://hortnews.extension.iastate.edu/2016/04-08/soilpH.html
At the end of the day…..• Your best bet is to do a soil test!• NDSU Soil Testing Lab
• $22-$70• https://www.ndsu.edu/snrs/services/soil_testing_lab/
For more information about soil health and amendments suggestions please contactAmy Koehler
Specialty Crop Instructor and Technician 701-228-5605
QUESTIONS?
