The effect on TSNAs of stick spacing in the barn
This study was designed to confirm the general consensus that closer packing in the barn (by placing the sticks closer together) results in higher TSNAs (Tobacco Specific Nitrosamines). We needed data to support our recommendation to growers to avoid close packing in the barn. We compared standard stick spacing (8 inches) with close stick spacing (4 inches), using a high converter selection of TN 90. The study was done over three years (2015-2017), with very different weather conditions. In two out of the three years (2016 and 2017), close spacing more than doubled TSNAs. In 2017, TSNAs were particularly high: total TSNAs of 11.3 mg/g in the standard spacing and 29.2 mg/g in the close spacing. The mean of the total TSNAs over the three years was 4.5 mg/g in the standard spacing and 10.8 mg/g in the close spacing. The year with no treatment differences (2015) was very dry during curing, and TSNAs were extremely low: 1.5 – 1.6 mg/g, which is abnormally low for this high converter line. We now have data to confirm that overpacking the barn has the potential to increase TSNAs considerably, especially in humid curing seasons.