Field-evolved insect resistance to transgenic Bt crops
Bruce E. Tabashnik, Aaron J. Gassmann, David W. Crowder,
Yves Carrière
Genetically engineered crops that produce Bacillus
thuringiensis (Bt) toxins kill some key insect pests and can
help to reduce reliance on insecticide sprays. Bt crops,
commercially introduced in 1996, now grow on more than 200
million ha worldwide. This widespread use elicits two
pressing questions: "How quickly will insects evolve
resistance to Bt toxins?" and "Will resistance be delayed by
planting refuges of non-Bt crops near Bt crops?" Here we
summarize our recent paper that addresses these questions by
analyzing global resistance monitoring data in conjunction
with results from computer simulations of the refuge
strategy.
Complete article:
pdf:
http://www.isb.vt.edu/news/2008/artspdf/aug0801.pdf
web:
http://www.isb.vt.edu/news/2008/news08.aug.htm#aug0801
Trends in
pesticide use on transgenic vs. conventional crops
Gijs A. Kleter et al.
Crop tolerance to otherwise phytotoxic herbicides generally
improves weed management, reduces the number and strength of
herbicide applications, and allows topical application of
herbicide to crop and weeds. Transgenic herbicide-tolerant
crops also permit more flexibility in the timing of
herbicide application. The new "post-emergence" herbicide
treatments for herbicide-tolerant crops may actually replace
both "pre-emergence" and "post-emergence" sprays with
conventional herbicides.
Complete article:
pdf:
http://www.isb.vt.edu/news/2008/artspdf/aug0802.pdf
web:
http://www.isb.vt.edu/news/2008/news08.aug.htm#aug0802
