Download Pesticides in the environment (Manual E, chapter 9)

Manual E, Chapter 9:
Environmental concerns
Dr. Vera Krischik
Department of Entomology
University of Minnesota
Manual E, Chapter 9: Environmental concerns
Learning objectives
• Understand the environmental benefits of
healthy turf.
• Identify first steps to avoid misapplication of
fertilizer.
• Develop an awareness of environmental
hazards associated with misuse of
pesticides.
Manual E, Chapter 9: Environmental concerns
Learning objectives
• Explain the difference between
“transportation” and “transformation”
• Understand how following appropriate
principles can reduce environmental
hazards
• Utilize he book to continue your
professional development.
Manual E, Chapter 9: Environmental concerns
Terms to know
• Transportation: The movement of a
pesticide away from its intended site.
• Transformation: When a pesticide’s
chemical structure is altered.
• Volatilization: When a pesticide changes
from a solid or liquid phase to a gaseous
phase.
Manual E, Chapter 9: Environmental concerns
Introduction
• Water contamination from grass is a big
concern.
• Dense healthy turf with thatch will absorb
fertilizers before they migrate off the
grass. Dense turf reduces the velocity of
runoff.
Manual E, Chapter 9: Environmental concerns
The benefits of turfgrass
• Produces per 25 sg ft enough oxygen for
one person for a day.
• Absorbs gaseous pollution such as carbon
dioxide from vehicles, lowering
greenhouse gases.
•Controls dust and pollen in air, which can
cause allergic reactions.
Manual E, Chapter 9: Environmental concerns
The benefits of turfgrass
• Provides significant cooling.
• Reduces noise by absorbing, deflecting,
refracting sounds
•Reduces discomfort from glare and light
reflection.
Manual E, Chapter 9: Environmental concerns
Use fertilizers responsibly
• Provides significant growth of turf
• Must be used responsibly.
• Use a soil test to determine fertilization
needs.
Manual E, Chapter 9: Environmental concerns
Use pesticides responsibly
• Overuse or misuse of pesticides results in:
• Reduction of bird populations
• Appearance of detectable residue in aquatic
systems
• Implication of pesticides as a carcinogen
Manual E, Chapter 9: Environmental concerns
Use pesticides responsibly
• Long term contamination of persistent
pesticides
• Destruction of nontarget organisms
• Evolution of pest resistant strains
Manual E, Chapter 9: Environmental concerns
Environmental influence
• The fate of pesticides can be grouped into
two classes:
• Transportation processes result in
movement away from the intended site.
Leaching and runoff potential may affect
water quality. Volatilization, Adsorption,
plant absorption
• Transformation processes result in an
alteration in chemical structure.
Manual E, Chapter 9: Environmental concerns
Environmental influence
• The fate of pesticides can be grouped into
two classes:
• Transformation processes result in an
alteration in chemical structure.
Photodecomposition, microbial
decomposition, chemical degradation
Manual E, Chapter 9: Environmental concerns
Environmental influence
• Transportation processes:
• Leaching: downward movement of
pesticides and nutrients into soil
• Runoff:
Precipitation rate exceeds he rate of
water infiltration into the soil. Movement
from row crops to bare soil. Dense turf
grass can reduce runoff.
Manual E, Chapter 9: Environmental concerns
Environmental influence
• Transportation processes:
• Volatilization: Change in form from solid to
gaseous. Vapor pressure is where solids
vaporize into liquids which evaporate.
Broadleaf herbicides formulated as esters
volatilize more than amine formulations. So
don not use ester above 80 to 85degrees F.
•Absorption: Movement of pesticide into plant
or mulch to be broken down
Manual E, Chapter 9: Environmental concerns
Environmental influence
• Transformation processes:
• Photo decomposition: Sunlight brakes down
pesticides for further degradation by
microbes. Dinitroanline herbicides (benefin,
trifluralin, pendimethalin, prodiamine)
• Microbial decomposition: Warm, moist soils,
ph 6.5 to 9.0 encourage microbial
decomposition.
• Chemical degradation: The hydrolysis of
pesticide and water.
Manual E, Chapter 9: Environmental concerns
Pesticide application practices
• Determine the economic threshold.
• Read the label.
• Timing
• Post application irrigation
• Application water volume
Manual E, Chapter 9: Environmental concerns
Application practices
• Never apply chemicals to waterways.
• Clean up spills. Never wash spills into the
street or hard surfaces that might lead to
sewers.
• Drop spreaders are more precise than rotary
spreaders. Near lakes do not use rotary
spreaders. Buffer zones of native plants
absorb nutrients.
Manual E, Chapter 9: Environmental concerns
Application practices
• Avoid fertilizers moving into natural
drainage.
• Return grass clippings to lawns to
decompose.
• Do not blow clippings onto hard surfaces.