BT MAIZE AND FUMONISIN REDUCTION IN SOUTH AFRICA 49


TABLE 2.3 Possible government interventions and their potential impact Intervention


Cancer Maize technology


Resistance to ear molds Insect-resistant varieties Knockout genes


Farmers or silos grading grain


Possible impact Major impact


Potentially high impact


Grading can eliminate the worst grain, but fumonisin can be prevalent without visible damage


Home processing


Supply commercial maize flour


Regulations Nutrition supplement Nutrition education Surveillance and treatment


Major impact Major impact


Limited impact—depends on consumption of commercial maize


No evidence Could have impact


Regular screening of rural people for EC with prompt surgery for those with tumors to reduce the asso- ciated high mortality rate


Source: Authors.


responsible for producing the fumonisin. PROMEC then saw in the literature that Bt maize, developed to reduce losses from insect pests, also had signifi- cantly lower levels of fumonisin (Munkvold, Hellmich, and Rice 1999; Dowd 2001; Bakan et al. 2002; Hammond et al. 2003). When Monsanto introduced the Bt gene in South Africa, PROMEC initiated efforts to collaborate with the company to determine whether this technology could reduce mycotoxins in rural villages. The first test compared Bt hybrids with their isolines on ARC experiment stations, where conditions could be controlled. These were first run in 2001/02, with a second round in 2002/03. Results were mixed. In some years in some locations Bt maize had much lower levels of fumonisins than did conventional maize, but in other years or locations little difference was dis- cernable. However, on average Bt maize had 60 percent less fumonisin than conventional hybrids (Rheeder et al. 2005). The government intervention, which this chapter examines, is the intro- duction and distribution of Bt maize seed to subsistence farmers. The


Possible impact Major impact


Potentially high impact


Grading can eliminate the worst grain, but fumonisin can be prevalent without visible damage


Major impact Major impact


No evidence


Folate appears to be effective


Could have impact No impact


Possible impact Possible impact Some impact


Testing for fumonisin levels by feed mills allows them to reject toxic maize


No impact No impact


Voluntary guidelines seem to have worked


No evidence


No evidence No evidence


Neural tube defects


Animal diseases


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