Field trials with low nicotine tobacco varieties developed by conventional breeding technique: first results
In 2015, the World Health Organisation (WHO) Study Group on Tobacco Product Regulation (“TobReg”) issued an advisory note recommending a strategy of reducing nicotine in tobacco to substantially lower levels of 0.4 mg/g. In the U.S., the Food and Drug Administration (FDA) is also actively considering this option.
Nicotine levels in the plant cannot be reduced without the development and availability of relevant new cultivars and massive changes in agronomic practices as it is a naturally synthesized alkaloid. Furthermore, to achieve viable “Very Low Nicotine” or VLN levels an extensive and lengthy research programme into targeted genetic manipulations would be necessary.
Following the publication of the WHO advisory note, a collaboration between breeders, leaf suppliers, farmers, and manufacturers was initiated in 2016. The aim was to assess low nicotine tobacco varieties in natural growing environments when both normal and extreme agricultural practices were applied. Both non-commercial and commercial Burley and flue-cured varieties were tested. Low nicotine varieties and controls were developed with conventional breeding techniques; GMOs were excluded due to regulatory restrictions on their use. The assessment focused on resistance to disease, leaf quality and taste, yields and farmer livelihood. Field trials were conducted in Zimbabwe and Malawi with the support of the Tobacco Research Board (TRB) and Agricultural Research and Extension Trust (ARET).
The first results showed low yields (around a 50 % reduction), poor aromatic characteristics, low quality and commercial value, with levels of nicotine still higher (>0.5 %dwb) than the WHO published target. These results raise a number of concerns from both a technical agronomy perspective and, more significantly, from the perspective of sustainable farming economics.
Additional investigations and field trials are planned to explore to what extent and duration improvements can be achieved. This is clearly a long-term project, as the development of viable new cultivars with reduced nicotine could take a decade, and commercialisation on a larger scale still longer.