Seed treatment with persistent pesticides might prevent early damage of the seedlings after germination, but little research has so far been done on this aspect. Longer-term solutions of naturally resistant or tolerant maize varieties to FAW attack might have potential, but are several years off. Research on tolerant maize varieties has been initiated in other countries.
Regarding the potential use of GMO (genetically modified) maize to control the Fall Armyworm in Africa, FAO considers that it is yet too early to draw conclusions. However, Bt maize has been clearly demonstrated to suffer far less damage impact from FAW compared to traditional open-pollinated maize varieties in all areas investigated, including the large-size commercial maize farms in South Africa. Although the Bt maize varieties are not yet officially registered against FAW in South Africa, the field reports indicate that most of the Bt maize events give excellent protection against FAW. However, some damage has been reported against single event Bt maize varieties in South Africa, and there is plenty of research evidence that FAW populations in the Americas have evolved resistance to some Bt maize varieties.
Nevertheless, more work still needs to be done including conducting trials and collecting data in South Africa. It must be borne in mind that the Bt maize grown currently in some parts of Africa is aimed primarily at controlling the maize stem borer insect and not the Fall Armyworm. However, until the Bt maize varieties are officially registered against FAW in South Africa under the Agricultural Remedies Act (Act 36 of 1947), the agricultural extension officers are not allowed to recommend the use of Bt maize for protection against FAW.
Maize has been genetically engineered by incorporating genes from the bacterium Bacillus thuringiensis (Bt) that produce insecticidal proteins that kill important crop pests. The use of Bt maize has resulted in some cases in reduced insecticide use, pest suppression, conservation of beneficial natural enemies and higher farmer profits. However, such benefits may be short-lived. Insect populations are able to adapt to Bt proteins through the evolution of resistance. Despite efforts to delay the selection for resistance, many cases of field resistance evolution among maize pests have been demonstrated in Bt maize, including in the Fall Armyworm in the Americas, and in South Africa in the maize stem borer,
Busseola fusca. Although the commercial maize farmers in South Africa practice a strict 'refugia' planting strategy as recommended by the GMO maize suppliers, it is likely that FAW will develop increasing insecticide resistance to GMO varieties and the commercial sector will have to carefully manage the GMO technologies going forward.
GMO maize is generally only used by commercial-scale maize farmers in South Africa, who have the resources and capital to plant these varieties. Most smallholder farmers do not have the resources to adopt the Bt varieties and continue to plant their open-pollinated varieties for the green maize cob market (roasted maize cobs sold by street vendors).
