Feasibility Assessments Coexistence Possible: Often With No Additional Effort

The European Commission’s Joint Research Centre (JRC) recently released a report confirming that it is possible for conventional agriculture and agriculture with genetically modified crops to coexist. In most cases, farmers can ensure GM material is sufficiently contained with little or no additional effort. Whether or not extra measures are needed greatly depends on variables like field sizes, prevailing winds, and the crop itself.

National governments and farmers need a scientific basis for making policies and decisions regarding coexistence. For this reason, the European Commission has been funding research to find out how coexistence can be put into practice. The JRC report released in February 2006 describes how various scenarios influence the spread of genetically modified material. For instance, the study looked at how the orientation of GM and non-GM plantings relative to prevailing winds affects unwanted pollen flow. The report also describes how the parcelling of land within certain regions affects the feasibility of coexistence.

The 2006 report describes coexistence for the crop and seed production of maize, sugar beet, and cotton. A previous study released in 2004 provided data on maize, rapeseed, and potato.

The smaller the field, the harder it is to prevent mixing with GMOs.

Factors influencing mixing The three greatest factors contributing to unwanted mixing between GM and conventional crops are: GMOs already present in conventional seed Out-crossing of pollen from GM plants onto neighbouring conventional fields GM material in shared machinery Agricultural producers may decide to take steps to manage each of these factors. Whether or not extra coexistence efforts are needed in a given situation depends on several circumstantial variables that are beyond the control of farmers: Field sizes: It is most difficult to ensure coexistence when small conventional fields (e.g. 5 hectares) are adjacent to large fields of genetically modified crops (e.g. 15 hectares). In such cases, extra measures are needed to ensure coexistence. Prevailing winds: As one would expect, out-crossing is more likely when a conventional field lies downwind of a field of GM crops. GM content in seed: Even seed for conventional crops may contain traces of GM material. GMO presence due to impure seed is later compounded by out-crossing and mixing during harvest. The EU has yet to define a threshold for adventitious GM content in seed. Thresholds ranging from 0.1 to 0.5 percent have been suggested.

Modular approach to presenting findings

Many different measures can be taken to prevent unwanted mixing between GMOs and conventional crops. Different efforts can be combined to achieve an optimised coexistence strategy. This is why the latest JRC study presented its findings in comprehensive tables to allow stakeholders to see how effectively specific measures hinder mixing under a wide range of conditions. The following coexistence measures were considered:

• Separation distances between GM and conventional crops
• Surrounding GM plantings with a buffer strip of conventional crops
• Planting cultivars with different flowering times
• Reserving machinery exclusively for GM or conventional crops or cleaning machinery after GM harvests

Maize: Problematic in regions of intensive cultivation

In many regions where maize is grown, no extra effort is needed to keep GM content in conventional maize fields below the 0.9 percent threshold. This is on the condition that GM content in seed is kept below 0.5 percent. For regions that pose particular challenges to coexistence, for example where fields are immediately adjacent or where small conventional fields lie beside large GM maize fields, additional effort is needed to ensure coexistence.

If harvesting machinery is cleaned after harvesting GM maize, 85 to 90 percent of conventional maize fields could be kept below the 0.9 percent threshold. If farmers plant buffer strips of conventional maize around GM plantings or keep isolation distances in addition to cleaning harvesting machinery, 100 percent of conventional maize fields can be kept below thresholds for labelling.

Regardless of management practices, keeping conventional maize harvests below very low thresholds such as 0.1 percent is not considered possible in regions where GM and conventional maize fields are interspersed and adjacent.

Separation distances between GM and conventional maize plantings required for upholding given out-crossing rates (extracted from 2006 JRC report)

The figures presented in the following table apply to GM maize fields of 15 hectares. The figures in the grey shaded areas of the table indicate minimum separation distances needed to maintain the corresponding level of GM content. The first distance applies to conventional fields upwind of a GM planting; the second distance applies to conventional fields that are downwind. Also included in the table is the effect of the size of the conventional field and the presence of conventional buffer strips around GM plantings. In addition to the data shown in the table, the study also investigated the effect of planting cultivars with different flowering times.

Added costs of coexistence for maize

When conditions require producers to implement added measures to ensure coexistence, additional costs can be expected. For example, planting buffer strips of conventional maize around transgenic maize involves added cost and effort on the part of the GMO producer. Furthermore, advantages conferred by GM crops such as increased yield are lost within the buffer strips. Additional cleaning of machinery is another potential added cost for coexistence – most likely 50 to 60 euro per cleaning, according to the study’s authors. In the end, producers will only grow GM crops if their advantages can justify additional costs.

Maize seed production: Depends on region

Seed producers implement stringent isolation measures to maintain the identity and purity of their seed. For example, maize seed farms maintain distances of 100 metres between adjacent fields, which would help reduce the likelihood of adventitious GM content in conventional maize seed production fields.

In regions without large scale GM maize production, keeping to a 0.5 percent threshold in conventional maize seed is possible without any added effort. Keeping GM content in conventional maize seed below 0.3 percent would require measures that could cut profits by up to 20 percent. Maintaining a 0.1 percent threshold is not considered feasible.

In seed production areas in close vicinity to large scale commercial GM maize plantings, observing even a 0.5 percent threshold would require increasing isolation distances to 400 - 600 metres – a measure that cannot be considered practical.

Sugar beet: Coexistence not a problem

Sugar beets are harvested before flowering, therefore mixing due to out-crossing is not considered an issue. The only likely source of GM content in conventional sugar beet culture would be traces of GMOs in sugar beet seed. Considering current seed production practices, keeping to a 0.5 percent threshold in seed will not pose problems. Keeping to lower thresholds of 0.3 or 0.1 percent would require additional efforts that would cut profits by 6 to 14 percent.

Cotton: No major issues

Cotton does not require any added effort (cleaning of machinery in worst cases) to keep harvests from conventional plantings below the 0.9 percent threshold when the GM content in seed is kept below 0.5 percent.

Results from prior studies

Studies conducted in 2002 compiled by the JRC assessed the effort and cost associated with preventing the spread of GM material under two scenarios: when GM crops are planted on 10 percent of fields, and when GM crops are planted on 50 percent of fields in Europe. In addition to maize, the studies looked at rapeseed, and potato. The studies were conducted before the 0.9 percent threshold for GM content came into force.

Rapeseed: 0.1% gets expensive

• There are no fundamental problems with observing a 0.3% threshold in rapeseed production when it comes to conventional farming.
• Achieving this goal for organic agriculture involves more extensive measures that correspond to significantly higher production costs. The main issue is volunteers. Volunteers, in this case, are rapeseed plants that grow from seeds that were unintentionally left behind or scattered. Without the use of conventional herbicides in organic farming, these GM volunteers become more of a problem.
• Maintaining a 0.1% threshold is extremely demanding under any scenario. Necessary, additional measures would mean an increase in production costs of up to 40%.
   

Potatoes: Cross-pollination not an issue

• Unlike maize or rapeseed, potatoes do not have problems with unwanted cross-pollination. This is simply based on the reproductive biology of potatoes and makes respecting a 1% threshold not a problem for all scenarios.
• Even so, abiding by a 0.1% threshold could be problematic. Unintentional mixing during the production of seed potatoes is conceivable, as well as mixing that could occur later, when potatoes are processed into food products. A threshold of 0.1% is not out of the question, but concrete data on how this could be realised would need to be collected.
   

More coexistence studies underway

• In 2004, the EU initiated a series of research projects to find out more about measures for ensuring coexistence and the economic consequences these could have in different regions throughout Europe.
• These projects will be incorporating the cooperation and opinions from as many social entities as possible to insure that their needs are taken into account and respected. Taking many different voices and concerns into account should result in findings that work for a wide range of European opinions and interests.

See also on GMO-Compass:

• The Netherlands: Coexistence with consensus