Pesticides Flashcards
What is specificity?
No pesticide is so specific that it kills a single organism
What is MDAF
Maximum Dose Always Fatal
Lowest does that will kill every member of a population
What is MDNF
Maximum Dose Never Fatal
Highest does that can be used without killing any members of the population
What is LD50
Lethal Dose 50
How much of that pesticide is needed to kill 50% of the population
What is persistence
How long the pesticide stays in the environment for
What is the problem with persistence
Increases chances of biomagnification and bioaccumulation
What is bioaccumulation
accumulation of liposoluable pesticides in the body. If unable to excrete them then it can become toxic
What is biomagnification
Pesticides which have accumulated in predators after eating prey
What factors control mobility
persistence, solubility, ease of vaporisation
Benefits of non-persistence pesticides
break down rapidly
can’t become concentrated
Organophosphate are less persistent than organochlorines
Which pesticides are more specific
Pyrethroid and oprganochlorines are both toxic but pyrethroids are less toxic to mammals.
What are systemic pesticides
Pesticides that are absorbed by the crop
What are the advantages of systemic pesticides
Don’t wash off
Will protect new growth
