The photo caption on page 95 of the April-June 2004 issue mentions that Bt cotton is widely grown in California and elsewhere. The “elsewhere” part is indeed true, but Bt cotton is not grown to any great extent in California. We simply do not have most of the Lepidoptera pests in California cotton that Bt controls. Statewide, only 7,400 acres of Bt cotton were grown in California out of the 2003 total of 691,930 acres, primarily in the Imperial Valley for pink bollworm control. In the San Joaquin Valley where most of the cotton is grown, there is virtually no Bt cotton grown.

Pink bollworm is managed in the San Joaquin Valley by the Cooperative Pink Bollworm Program, which is funded almost entirely by cotton growers and operated by the California Department of Food and Agriculture. The program uses an integrated pest-control approach, relying on trapping, sterile release, crop destruction and occasional pheromone treatments to keep infestations below economic impact levels. There may be some acres of it grown because the Bt technology was combined — so called stacked — with glyphosate-resistant (Roundup Ready) cotton, which is very common and important in California, but if so it clearly is not grown because of the Bt trait.