Morphologico-topographical and biochemical peculiarities of sugar beet roots

Spatial distribution of sucrose, ash, nitrogen and reducing substances in the sugar beet roots, classified according to its morphologico-anatomic structure into 16 zones (parts), was studied in model laboratory trials and topographical analyses. At the same time, respiration rate (metabolic quotient - QO2) and specific activity of invertase (beta-D-fructo-furanosidase) were studied in these 16 or 7 parts of the root. On an average of five model trials, it was found out that chemical composition of different parts of the root is considerably variable and this is also conditioned by the size and shape of the root. Great differences can be seen especially in sucrose content, reducing substances, amides and free amino acids. The root exhibited the worst chemical and technological composition at the minimum sucrose content and comparatively high contents of nitrogeneous substances, ash (especially alcaline, molasses forming components - potassium and sodium) and reducing sugars. There is a slight better proportion between sucrose and the mentioned ballast substances in hypocotyl and the best one is in the radix, especially in its upper part. No previously expected correlation between chemical composition, particularly sucrose content and respiration rate, was confirmed. The maximum QO2 is exhibited by epicotyl and the minimum (comparatively by 55 per cent lower value) QO2 value is in the narrowed part of radix. As far as the specific activity of invertase is concerned, the maximum was found in the epicotyl (100 per cent), less in hypocotyl (67 per cent) and the minimum was determined in the upper part of radix. Principal parameters of technological quality of sugar beet for different parts of the root were calculated and derived from the results of model laboratory trials and topographical analyses, and an optimum height of cut, at which the sugar beet of the highest quality is obtained, was defined.