GLYPHOSATE RESISTANT CREEPING BENTGRASS: SAME SONG SECOND VERSE. Carol Mallory-Smith*; Oregon State University, Corvallis, OR (122)


Creeping bentgrass (Agrostis stolonifera) is a perennial, obligate outcrossing species mainly used on golf courses. Glyphosate resistant (Roundup Ready) transgenic creeping bentgrass was developed by Scotts Company and Monsanto.  While still a regulated article, it was planted in Oregon and Idaho for seed production. In Oregon, about 160 ha were planted in Central Oregon near Madras.  After swathing but before combining, a wind storm moved panicles from the fields.  The fields were removed from production in 2003.  Because the transgenic creeping bentgrass was still a regulated article, all transgenic creeping bentgrass plants were required to be found and destroyed.  Seven years after the removal of the fields, transgenic creeping bentgrass plants are still being found near the Madras fields.  In Idaho, production fields were planted in Canyon County under notification in 2003 and 2004 and under permit in 2005 and 2006.  It is not clear why there was a change from notification to permit for the production but a permit is more restrictive than a notification. According to Scotts Company, the size of the fields, the harvest dates, and the years the fields were removed are considered to be confidential business information. The fields likely were harvested in either 2005 or 2006 or both. Transgenic creeping plants were found in Canyon County after the fields were removed from production.  In October 2010, the presence of transgenic creeping bentgrass was confirmed in Malheur County in Oregon. Transgenic creeping bentgrass was never planted in Malheur County but Canyon County is just across the Snake River. The plants are likely the result of seed movement from the Idaho sites possibly on trucks or other equipment. The transgenic creeping bentgrass has spread along irrigation canals, ditches, and roadsides.  It also has been found in pastures and production fields.  The transgenic creeping bentgrass is still a regulated article. There were no mitigation plans for gene movement in place for either the Madras or the Canyon County sites.  There are no herbicides presently labeled that are permitted to be used along the water ways that are effective for controlling established glyphosate resistant creeping bentgrass.  The failure to consider creeping bentgrass biology, ecology, production practices, and control options led to the erroneous opinion provided by the Weed Science Society of America stating that Roundup Ready creeping bentgrass would not be a problem and could be controlled by other herbicides. The major issue not addressed in the opinion was that lack of herbicides that can be used near water ways where the most used and effective herbicide is glyphosate.  The authors failed to consider the potential for gene flow during seed production which is very different than what would occur in a turf situation.  This example of transgenic creeping bentgrass provides insight into the complexity of preventing gene flow, the inadequacy of the monitoring requirements, and the difficulty in retracting a gene once it is released let alone determining how far the transgene has moved.