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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.

This study was conducted to evaluate the effect of sowing rates and organic fertilization on growth and yield biomass quality of chia crop. The agronomic performance and nutritive value of chia were analyzed in order to define alternatives to local forages for dry-season feeding of ruminants in the Mediterranean region. Two sowing rates were arranged in the main plots and three levels of organic fertilization in the subplot with three replicates in split-plot design. Chia growth was not affected by sowing rates and fertilization. Concerning the dry weight and leaf area index (LAI), there were no significant differences among fertilization treatments while sowing rates influenced both dry and LAI, which were significantly increased as sowing rates increased. Forage quality traits were not significantly influenced by sowing rates. With regard to crude protein content, fertilization treatments had a positive effect. The greatest values were observed under manure treatment. Moreover, significant incre...

SUMMARYThe presence of velvetleaf (Abutilon theophrasti) in crops is increasing in arid and semi-arid environments. Field experiments were conducted in Greece in 2009 and 2010 to determine the influence of velvetleaf emergence time and maize (Zea mays) hybrids with different growth rates on maize yield and velvetleaf growth and fecundity. Velvetleaf was uniformly seeded in order to emerge at the 1, 3, 5 and 7-leaf stage of maize (V1, V3, V5 and V7 growth stages, respectively). Velvetleaf biomass, canopy area and seed production were significantly affected by the date of velvetleaf emergence. Velvetleaf plants emerging just after maize (V1) produced 7–17 times lower seed number, compared with the V5 growth stage. Maximum maize grain yield loss ranged from 26 to 37% for early emerging velvetleaf, and less than 6% yield loss occurred from velvetleaf seedlings emerging at V7 growth stage. Maize hybrids with high initial growth rate seem to be more competitive than the other hybrids. The results of this study are essential in the development of an integrated weed management strategy for maize in semi-arid environments, since they highlight the importance of the careful selection of a competitive maize hybrid and avoidance of early velvetleaf emergence.