<p style="text-align: justify;"><b>Field Testing</b></p>

<p style="text-align: justify;">The transgenic sugar beet line GTSB77 was field tested in the United States (1996 &ndash; 1998). GTSB77 was evaluated extensively and agronomic data showed that there were no significant changes in the number of seeds produced, germination characteristics, final stand, over-wintering capability, or pathogen susceptibility.</p>

<p style="text-align: justify;"><b>Outcrossing</b></p>

<p style="text-align: justify;">Sugar beet is an outcrossing, largely wind pollinated, plant. It is normally a biennial, developing a large succulent root in the first year and a seed stalk the second. Certain conditions such as low temperatures after planting and longer day length may induce bolting and produce a seed stalk during the first growing season. Beet is also highly sensitive to frost and a poor competitor with other plants.</p>

<p style="text-align: justify;">During the reproductive phase, large amounts of pollen are produced which can travel long distances. The genus Beta, including the wild relatives, is divided into four sections: Beta, Corolinnae, Procumbentes, and Nanae. Sugar beet hybridizes freely with all members of the section Beta and the resulting progeny are fertile but hybridization is unlikely with other members of the Chenopodiaceae family. Hybrids between sugar beet and members of the other three sections do not naturally occur without human intervention. Assuming proximity, synchrony of flowering and suitable conditions, <i>B. vulgaris</i> may freely hybridize with other varieties.</p>

<p style="text-align: justify;">During production of GTSB77, for purposes other than seed production, plants are harvested before the natural onset of the reproductive phase in the same manner that unmodified cultivars are grown. Since it is uncommon for sugar beets to bolt, except in fields or plots grown specifically for seed production, there is little opportunity for uncontrolled pollen flow due to adequate isolation distances enforced by seed certification agencies.</p>

<p style="text-align: justify;">Specific concerns have been raised about potential outcrossing with subsp. macrocarpa, in the Imperial Valley, California. Isozyme studies indicated the introgression of genes from commercial sugar beets has occurred, although other reports show that gene flow between these two plant populations is not likely due to non-synchronous flowering periods, sterile F1 hybrids, and poor growth in F2 hybrids.</p>

<p style="text-align: justify;">It was determined that the transgenic sugar beet line GTSB77 was no more likely to become a weed than herbicide tolerant cultivars currently in use or that can be developed by traditional breeding techniques. GTSB77 was unlikely to increase the weediness potential of any other cultivated plant or native wild species with which it may interbreed.</p>

<p style="text-align: justify;"><b>Weediness</b></p>

<p style="text-align: justify;">Sugar beet plants are not a serious weed, although sugar beets have escaped cultivation and their progeny have persisted in the environment for many years. Occasionally, sugar beet volunteers may arise from the presence of wild beet, the bolting of fodder beet plants, the development of groundkeepers which arise initially from vegetative growth of beet crowns or tops left after harvest or the germination of seed (which may be dormant in the soil for up to 10 years). Volunteer plants may be controlled by mechanical means or the use of registered herbicides that can be used on sugar beet volunteers.</p>

<p style="text-align: justify;">Sugar beet plants have escaped from past commercial cultivation in the San Francisco Bay area and persist to this day. However, transgene movement via pollen to these plants is highly unlikely as sugar beets are no longer in commercial production in the Bay area. Other populations of sexually compatible plants are located in the Imperial Valley of California, but no wild populations exist outside of California.</p>

<p style="text-align: justify;">The movement of the glyphosate tolerance trait from GTSB77 to any other sexually compatible plant should not have a significant impact as the glyphosate tolerance would not confer any competitive advantage to these plants, especially if glyphosate is not applied to these plants. This would only occur in managed ecosystems where glyphosate is applied for broad-spectrum weed control, or in plant varieties developed to exhibit glyphosate tolerance and in which glyphosate is used to control weeds. As with glyphosate tolerant sugar beet volunteers, these individuals, should they arise, would be controlled using other available chemical means. Hybrids, if they developed, could potentially result in the loss of glyphosate as a tool to control these species. However, this can be avoided by the use of sound crop management practices including not using the same herbicide every year.</p>

<p style="text-align: justify;"><b>Secondary and Non-Target Adverse Effects</b></p>

<p style="text-align: justify;">It was concluded that the genes inserted into the transgenic sugar beet line GTSB77 would not result in any deleterious effects or significant impacts on nontarget organisms, including threatened and endangered species or beneficial organisms. The enzyme EPSPS that confers glyphosate resistance is from a commonly occurring soil bacterium, <i>A. tumefaciens</i>, and is similar to the gene that is normally present in sugar beets and is not known to have any toxic properties. Field observations of line GTSB77 revealed no negative effects on nontarget organisms. The lack of known toxicity for this enzyme suggests no potential for deleterious effects on beneficial organisms such as bees and earthworms. The high specificity of the enzyme for its substrates makes it unlikely that the introduced enzyme would metabolize endogenous substrates to produce compounds toxic to beneficial organisms.</p>

<p style="text-align: justify;">The chimeric-GOX fusion protein (Protein 34550) was unlikely to pose any risk. First, the amount was not detectable in plant tissue, it had no enzymatic activity, and the protein it was fused to is a normal constituent of sugar beets. Additionally, the scoreable marker protein, beta-D-glucuronidase, is a well-characterized protein with no known toxicity.</p>

<p style="text-align: justify;"><b>Impact on Biodiversity</b></p>

<p style="text-align: justify;">Genetically engineered line GTSB77 sugar beet is no more likely to become a weed than herbicide tolerant cultivars currently in use or that can be developed by traditional breeding techniques. It is unlikely to increase the weediness potential of any other cultivated plant or native wild species with which it may interbreed. It will not harm non-target organisms and there is no potential impact of line GTSB77 on biodiversity.</p>
