TRANSGENIC COTTON

Charles Hagedorn

Extension Specialist - Biotechnology

This page is dedicated to information on the development, release, commercialization, and field performance of genetically engineered (transgenic) cotton. By 1/98 there were four commercial transgenic cotton lines, one was the so-called "Bt cotton" that imparted insecticidal properties to the plant, while the other three were herbicide-tolerant lines. By 1/99 there were several dozen transgenic varieties available that contained Bt, herbicide tolerance, or both (the so-called "stacked" varieties). The major transgenic mechanisms in cotton are:

Insect resistance (Bt) - Monsanto (controls tobacco budworm, cotton bollworm)
Glyphosate (Roundup) tolerance - Monsanto
Bromoxynil (BXN) tolerance - Monsanto/Calgene/Rhone Poulenc
Sulfonylurea (SU) tolerance - DuPont

Of the U.S. cotton acreage (approximately 12.5 million acres), roughly 25% was planted to transgenic varieties in 1997, this increased to 45% in 1998, and cotton industry predictions are that the entire U.S. acreage will be planted to transgenic varieties within the next five years. Many different varieties are now available that contain one of the four genetic mechanisms (above), and new lines have been developed that contain more than one mechanism. Lines containing the Bt and "Roundup Ready" mechanisms, and lines containing the Bt and BXN tolerance mechanisms first became available for the 1998 planting season.