Spain Bt maize prevails

Spain was for a long time the only EU land using genetically modified plants agriculturally. The insect-resistant Bt maize has been grown there since 1998. In the meantime, it has established itself with almost blanket coverage in regions with heavy Pyralidae (corn borer) infestations. In 2009, Bt maize was cultivated on 76 057 hectares, which represents about one fifth of the total Spanish maize acreage.

With a total area of 340 000 hectares, Spain occupies the sixth place on the list of maize-producing countries of the EU, behind Romania, France, Hungary, Italy and Germany. For over 10 years Bt maize has been grown in many regions of Spain. The acreage increased continually until 2008 and reached almost 80 000 hectares. Spanish Bt maize is used almost exclusively for animal feed.

Acreage of Bt maize in Spain 1998–2009 (in hectares) Source: Ministry of Agriculture; Brookes, USDA, KWS. Field with Bt maize, in the area of Seville (summer 2001). Source: Fundacion Antama . Damage due to the European corn borer: Yield losses through bent or snapped off plants

Regions with heavy Pyralidae infestation: Bt maize is worth it Bt maize is grown predominantly in the Aragon and Catalonian regions, with 32 000 and 25 300 hectares, respectively, in 2008. In these regions the infestation with European corn boreris very heavy and the cultivation of  Bt maize is an attractive economical alternative to the long-used method of combat with chemical insecticides. These have little effect and pollute the environment. Despite the use of insecticides the farmers here have to put up with a loss of yield of between 6% and 20%. Totally abandoning the use of insecticides, which is possible in regions with only weak infestations, would lead to a loss of harvest of up to 80%. Almost a quarter of the Spanish maize acreage lies in regions with very heavy corn borer infestations, and another 40% in areas with average pest pressure. In all, the acreage of maize for which the use of Bt-maize would be economically viable is estimated to be 180 000 hectares. The farmers could compensate the higher costs for the Bt maize seeds through the considerably decreased harvest losses and savings on pesticides. According to an investigation by a British consulting agency PG Economics, Spanish farmers growing Bt maize have improved their yields by on average 6.3% and their economic results by 13%. A evaluation published in 2007 calculated an increase in gross profit of about €100 per hectare, that can be shown to be due to the utilisation of Bt maize.

A census of farmers carried out by scientists from the University of Cordoba established a general increase in harvest yields through the utilisation of Bt-maize in 2002–2004; however, this was only statistically significant for the region of Aragon (11.8%) - presumably due to the very high pest infestation there. The increase in gross profits here in the 3 years was on average at €122 per hectare. On 70% of the Bt maize fields no additional insecticide was used, whereas only 42% of the fields under conventional maize managed without use of insecticides.

In regions with a light corn borer infestation, farmers only have to face a small loss of yield. Here the use of insecticides is, weighed against to its effect, much too expensive. Under these conditions there are no advantages in growing Bt maize.

Large range of Bt maize varieties

In the meantime, numerous types of maize are available for the Spanish farmers. In 2007, almost 50 different types of Bt maize had been approved that all contained the gene constructionof the GM-maize MON810 that had received approval from the EU in 1998.

In the first years of cultivation, only one type of maize (Comba) from the insect-resistant Bt176 strain was marketed in Spain. Bt176-maize was approved in 1997 in the EU: it has an antibiotic resistance gene (Ampicillin), which according to an expert opinion of the European Food Safety Authority (EFSA) should, as a precaution, no longer be used in commercially used GM-plants. The Spanish government rescinded the marketing authorization for Bt176 in April 2004.

See also on GMO-Compass:

• Global cultivation area of GM maize