Pesticides Ch 20-23

The breakdown of pesticides in the environment

Degradation

Accumulation of pesticides in the body of an organism

Bioaccumulation

Buildup of pesticides throughout multiple organisms via the food chain

Biomagnification

Which soil texture has the highest rate of permeability?

Sand

Pollution that comes from a specific, identifiable place

Point Source

Pesticides that are ______ soluble in water are very likely to leach, potentially contaminating groundwater and move with water in surface runoff.

Highly

Fresh water flowing in aquifers beneath the soil surface

Groundwater

 Pesticides that are strongly adsorbed by soil particles may be moved from the site in soil erosion.

True

Pesticides that are __________ soluble are rapidly flushed from the soil and pose less risk of soil pollution.

Highly

The degradation of pesticides can be caused by

Soil Micro-organisms

Measure of how long a pesticide remains active at the site of application or in the environment

Persistence

The deeper the topsoil, and the higher the organic matter content, the _____ the likelihood there is of pesticide reaching the groundwater.

Less

Surface water is more likely to become pesticide contaminated if soil is

Compacted

What can be added to pesticide mixtures in order to thicken the formulation and reduce pesticide drift?

Adjuvants

The application of pesticide beyond the target area

Pesticide Overspray

What is the most important factor of weather related pesticide drift?

Wind Speed

What natural process can provide the opportunity for drift?

Temperature Inversions

May go undetected unless it is visible or leaves a residue

Pesticide Drift

Perfectly calm conditions would be the ideal time for pesticide application with minimal danger of drift.

False

Spray droplets will _________ in size, thus drift less, if the spray pressure is __________.

Increase, Decreased

Will decrease the coverage of the pesticide on treated plants

Thickening Agents

Low relative humidity and/or high temperatures cause _________ pesticide droplet size due to evaporation.

Smaller

The most important factor affecting drift of aerial applications

Droplet Size

One way to describe the coarseness of the spectrum of spray droplets from the nozzle

Volume Median Diameter (VMD)

Will influence the coverage of a pesticide on its target and the likelihood of pesticide drift

Nozzle height, type, and spray pressure

Toxicity to plants

Phytotoxicity

Almost all pesticides can cause plant injury if they are applied at too high a rate.

True

May occur to plants planted into soil containing a persistent herbicide

Phytotoxicity

Beekeepers are to be notified of pesticide application if

Pesticide is labeled toxic to bees and/or beekeeper submits written request

Alerts the user to look for specific bee-related restrictions in the directions for use section of the label

Pollinator protection box on label

Poses the most serious problems for fish and other wildlife and most likely when pesticides are both persistent and accumulative

Sublethal pesticide exposure

Indicated by a number code on the pesticide label

Mode of Action

Pesticide resistance is more likely if the pest has a _________ life cycle.

Short

Occurs when there is a reduction in the natural enemies of that pest

Pest Resurgence

Inherited/genetic ability of individuals in a population of pests to resist the effects of a pesticide, and pass that ability on to future generations of the pest

Pesticide resistance

Occurs when a pest that formerly caused little damage begins to cause significantly more damage than the primary pest

Secondary Outbreak

Pests, pathogens, or weeds become resistant to two or more chemically related pesticides

Cross Resistance

Happens when pests are resistant to more than one mode of action

Multiple Resistance