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re: Re: GE in OZ -Reply

Comments by:       Craig Harris@SOC@SSC
Forwarded to:      out[sanet-mg@ces.ncsu.edu,ACLARK@crop.uoguelph.ca]
Comments:      


   -------------------------- [Original Message] -------------------------      
just to add a couple thoughts to ann's original message . . . anytime the Bt 
toxin is used rather than the Bt beasties themselves, resistance will develop 
. . . if the beasties themselves were used, then they could coevolve with 
their host, but an inert chemical, whether synthetic or natural, cannot evolve
. . . the rate at which resistance will develop will be affected by the 
intensity and spatial distribution of the application; making high levels of 
Bt toxin available year-round everywhere will produce resistance the most 
quickly
turning to the question of what is being lost, one of the main benefits of Bt 
is that it is a relatively soft pesticide (short-lived, narrow spectrum) . . .
thus it can be used to reduce an outbreak of a pest without seriously 
disrupting the natural community of pest predators . . . this makes it very 
useful in ipm applications where one is trying to get as much protection as 
possible from non-chemical controls (barriers, predators, diseases) while 
having a chemical in reserve for serious outbreaks that will not disrupt the 
basic pest management system
thus, Bt could help growers transition to more sustainable pest management 
systems if its efficacy is not seriously diminished
cheers,
craig

craig harris
dept of sociology
michigan state university


Bob MacGregor <RDMACGREGOR@gov.pe.ca> wrote Wednesday, April 30, 1997  9:54:46 EDT:
Ann,Is the point, then, that this is inevitable?   It seems you are saying 
that this will happen sooner or later -- a bit sooner is the GE crops arewidely-used -- a bit later if acreage is just sprayed with Bt or Roundup.Does avoiding use of these biocides -- particularly the GE ones -- domuch more than buy us a 
little time?  Time to do what?   We will alwaysneed tools to battle against the things that want to take our crops from usand/or take the space that our crops 
occupy.  The challenge is to lookinto the crystal ball and see which will be benign (or least malignant).  I think most on the list will recognise this is a pretty big challenge.BOB