| Popis: |
The influence of moment of harvesting on agronomic and some chemical properties of flue-cured tobacco was investigated in Slatina during the 2004 – 2005 year. The experiment was set up according to the split – split plot method with four replications. Three tobacco cultivars (HVT-1, VJ-17, DH-17) topped at 20 and 17 leaves for harvesting were harvested at the phase of visually estimated technological maturity (base treatment), one harvest earlier (immature tobacco) and one harvest after visually estimated technological maturity (over-mature tobacco) in each of two years. Observation was made on yield, price per kilogram, value per hectare and nicotine, total N and reducing sugars content. In two years average the best economical properties according to yield, price per kilogram, value per hectare were achieved with cultivar HVT-1. Only a slightly lower yields were obtained with delayed harvest from immature to over-mature harvested tobacco leaves and in the first year of investigation value per ha decreased significantly. There were differences with respect to chemical properties of the leaf among varieties and seasons ; however the direction of change with increasing maturity remained fairly consistent. Increasing maturity resulted in increases in nicotine and total N content and decreases in reducing sugars content, significantly in 2005 year. The results of these studies support the view that, for best agronomic results and for maximum quality tobacco should not be harvested at over-mature stage. |
