Narrow row spacing increased yield and decreased nicotine content in sun-cured tobacco (Nicotiana tabacum L.)

Sun-cured tobacco (Nicotiana tabacum) is one of the most important industrial crops for Greece and other Mediterranean countries. A field experiment was conducted in 2012 and 2013 under organic conditions in Agricultural University of Athens in order to compare the growth, yield, nicotine and sugar content of three Greek sun-cured tobacco cultivars at two between-row spacings. Three cultivars of the Greek Basmas were sown in a seedbed in a greenhouse and then transplanted in the field at distances 10–and 20–cm between rows. The experimental design was a split-plot in a randomized complete block with three replicates. Tobacco was harvested at 80, 95, 115, and 135 days after transplanting (DAT). Our results showed that wider row spacing resulted in lower yield than closer row spacing for all three cultivars. Cultivars × year interaction was significant for total yield. Tobacco yield ranged from 1315 to 1920 and from 1545 to 2090kgha−1, for the wider and narrower row spacing, respectively. Chemical analysis revealed that nicotine content was also affected by cultivar and row spacing and ranged between 3.40 and 5.19%. Narrow row spacing resulted in reduction of nicotine content, while sugar content was only affected by cultivar. Narrower row spacing could be used in some cases for a higher production of tobacco of lower nicotine content, whenever this is desirable for blending purposes.