Crop Specific Safety Concerns Sugar Beet

Every crop has a different relationship to the environment, which means environmental impact assessments must be conducted on a case-by-case basis. Different crops pose different threats when it comes to out-crossing or escaping cultivation. The following plant specific characteristics are taken into account for risk assessment.

General information

Sugar beet (Beta vulgaris) is a common crop in Europe, especially in Denmark, France, and Germany. Wild relatives of sugar beet originated from Asia Minor. Breeding beets for sugar production has taken place since the late 18th century.

Sugar beet is a biennal plant. The large, succulent roots of sugar beet used for food and feed production are harvested at the end of the first year of growth. If left to grow, sugar beets will flower and produce seeds during the second year. Sugar beets are only allowed to flower for seed production, which mainly takes place in France and northern Italy.

The sugar beet's wild relative, the sea beet, Beta vulgaris ssp. maritima, is an annual in southern Europe and a biennal or perennial in northern latitudes (Scandinavia, Ireland etc).

Is out-crossing of transgenes from sugar beet possible?

Out-crossing and hybridisation are limited because sugar beets are harvested before flowering. Only bolters - sugar beets that flower during the first growing season - can hybridise with each other or with wild relatives when present.
Sugar beets are cross-compatible with other species in the genus Beta such as B. vulgaris ssp. maritima, B. marcocarpa, and B. atriplicifolia. There is no evidence that B. vulgaris can intercross with other genera in the Chenopodiaceae family.

Can cultivated sugar beet survive in the environment?

Beets predominantly reproduce by seed, although plants can sometimes grow back from portions of roots left in the field after harvest. Volunteer sugar beets are rarely observed growing among other crops, in ditches, or on roadsides. If volunteer sugar beets were to occur in subsequent crops, they could be controlled by agricultural practices (herbicides, tillage during seed bed preparation). Most seeds left in the upper 5 centimetres of soil will germinate. Seeds that are ploughed deeper may remain dormant until conditions favour germination. Beet seeds can remain dormant for over 10 years.

Problems with volunteer beets sometimes occur when planted on the same field for several consecutive years. Emerging annual weed beet from the seed bank can only be controlled by mechanical means, and only to a certain degree. Remaining volunteers can reproduce and could potentially cross with bolting, transgenic sugar beets.

Sugar beet is sensitive to frost and is poorly competitive in natural or agricultural habitats.

Beet seeds are dispersed only over short distances. Pollen grains are dispersed mainly by wind, but insects can play a small role. Beet pollen, however, is quite sensitive, and is viable for no more than 24 hours under field conditions.

In general, sugar beet does not survive in the environment. Only hybrids with wild beets can withstand natural competition and low winter temperatures.