Development of Pale Yellow Dark Burley

The Surgeon General's 2014 Report on smoking attributes the increase in certain cancers with the TSNA in the burley component of American blend cigarettes. Amongst the various methods of reducing TSNA, screening seed to eliminate high converters has reduced the overall TSNA levels in burley considerably, and efforts are now underway to introduce the demethylase-gene mutants into commercial varieties to reduce the TSNA further. A third approach to reduce TSNA is the use of green tobacco which does not accumulate as much TSNA as traditional burley probably because green tobaccos require only about one third of the amount of nitrogen fertilizer to produce acceptable yields. There is some interest in a green burley type product because various companies have contracted growers in Kentucky to grow limited amounts of Maryland, the most recent being in 2015. The main problems with currently available Maryland varieties are its lower yield than conventional modern burley varieties and perhaps more importantly, its propensity to cure with some green discoloration if the curing conditions are not ideal,. This curing problem can be rectified if the Maryland contains the "pale yellow" gene which promotes the rapid degradation of chlorophyll once the tobacco is harvested. Several early generation lines of this "pale yellow dark burley" were grown, harvested and cured on the University Farm in 2015 and the quality will be evaluated though January 2016.