Effect of seed stimulation on germination and sugar beet yield

Germination and sugar beet yield after seed stimulation were investigated. The seeds came from the energ'hill technology and were subject to laser irradiation. The experiments were conducted in the laboratory and field conditions. Lengthening of germinal roots and hypocotyls was observed. A positive effect of the stimulation on the morphological features was observed for the Eh seeds and laser irradiation applied in a three-fold dose. The energ'hill seeds exhibited a significantly higher content of carotenoids in seedlings and an increase in the content of chlorophylls. Laser light irradiation favourably modified the ratio of chlorophyll a to b. The leaves and roots of plants developed from the energ'hill and irradiated seeds were characterized by higher dry matter content thanin non-stimulated seeds. Seed stimulation had a positive influence on yielding and the saccharose content.

Yields and root technological quality of sugar beet grown in crop rotation and long-term monoculture

The paper presents the findings of 6-year (1993–1998) investigations obtained in the field static experiment continued since 1967. This experiment concerned the estimation of the crop yield and its structure, and root technological quality under the conditions of crop rotation and extreme shortening of the rotation, i.e. monoculture. Investigations have proved that under agroclimatic conditions of north-eastern Poland it is possible to obtain 60 t of roots per ha in a naturally correct crop rotation, while in a long-term monoculture – 33 t, and 36 t and 19 t of top, respectively. The differences in monoculture crops occurred as a result of a plant loss during germination by 5.6%, and a smaller unit weight per root by 41.6%. The applied procedures of plant protection by herbicides and fungicides improved the root and top crop and favored the maintenance of plant density. A lowering of saccharose content in roots from 15.7% in the crop rotation to 15.0% in monoculture was recorded, and of sugar yield in the technological process from 13.0 to 12.3%, respectively. A high white sugar yield was obtained in crop rotation – 7.89 t per ha, while in monoculture it was only 4.06 t, i.e. 48.5% less.

Saccharides of yacon [Smallanthus sonchifolius (Poepp. et Endl.) H. Robinson] tubers and rhizomes and factors affecting their content

Yacon [Smallanthus sonchifolius (Poepp. et Endl.) H. Robinson], a native plant of the Andes, belongs to the family Compositae (Asteraceae). It represents a traditional crop from the original population of Peru. Most of the tuberous root biomass is constituted by water (> 70% of the fresh weight). Saccharides, especially oligofructans, form 70–80% of their dry weight. Four yacon ecotypes originating from Bolivia, Ecuador, Germany and New Zealand were cultivated on the trial fields of the Czech University of Agriculture in Prague in 1995, 1996, 2000 and 2001. Considerable differences among the ecotypes were observed in their content of inulin (141–289 mg/kg d.m.) and lesser for fructose levels (195–217 mg/kg d.m.). No differences were found in glucose and saccharose contents. The highest inulin and fructose contents were found in the harvests from 2001 and 2000, similar trends were found for glucose. Statistically significant effect on the content of all saccharides has the year of cultivation. Tubers contained much higher levels of inulin (179 g/kg d.m.) and fructose (193 g/kg d.m.) in comparison with rhizomes. No significant differences were found for saccharose (higher in rhizomes) and glucose (lower in rhizomes). The contents of inulin and fructose in the upper and lower parts of tubers were reciprocal. During the storage period of 140 days at10°C and 75% a relative humidity inulin content decreased by 48.7% and monosaccharides content increased (fructose by 9.97%, glucose by 31.4%) due to hydrolysis. Likewise saccharose content increased by 12.9%.

Physicochemical characterization of natural honeys from different regions in Slovakia

This study is intended to determine the physicochemical characteristics of Slovakian honeys, and compare them with specifications described in the Codex Alimentarius Standard, the European Ho­ney directive, the Slovak Codex Alimentarius and Slovak standard No. 1/2006. In addition, we tried to find out correlations between individual constituents of honeys. Physicochemical characterization was carried out following the harmonized methods dictated by the International Honey Commission IHC. Honey samples (n=50) were collected from three honey types (blossom, blends, honeydew), and from the three main Slovakian geographical regions (named ‘east’, ‘middle’ and ‘west’). The phy­si­co­che­mi­cal evaluation included moisture, reduced sugars, proline, hydroxymethylfurfural (HMF), conductivity, diastase and invertase activity, pH and water activity, following the techniques proposed by the European Honey Commission (EHC). The moisture content in the honey varied from 15.26 to 17.65 %, HMF levels ranged from 21.83 to 63.00 mg . kg−1, the diastase activity varied from 21.01 DN to 36.67, invertase activity varied from 121.73 to 164.11 U . kg−1, the proline content varied from 426.56 to 531.79 mg . kg−1,the fructose content values were found from 36.33 to 40.20 g . 100g−1, the glucose content values ranged from 27.67 to 31.00 g . 100g−1, the values of saccharose content were from 0.15 to 0.37 g . 100g−1, the conductivity varied from 29.48 to 97.24 mS . cm−1,the pH value varied from 4.06 to 4.80 and the water activity content varied from 0.55 to 0.57. Significant differences (P ≤ 0.05) were found between HMF and fructose, glucose and saccharose and conductivity and pH, significant differences (P ≤ 0.01) between fructose and glucose and significant differences (P ≤ 0.001) were found between HMF and conductivity. Between blossom honey and honeydew honey were found statistical significant differences in HMF (P ≤ 0.05) and conductivity between honeydew honey and blossom honey (P ≤ 0.001). Among regions were determined statistical differences between HMF and invertase (P ≤ 0.05) and conductivity (P ≤ 0.01).

The Role of Cultivation Systems in Quality Sugar Beet Production

Producing sugar beet, as it is a demanding field crop, has contributed to the raising standard of plant production. It has an outstanding place among the plants that are cultivated in the intensive plant production system. Rentability of sugar manufacture is determined by the stability of yield and the quality (saccharose content) of sugar beet. In this way, the fundamental interest both of the producers and the processing industry is high yield and quality, year by year. The yield and the quality of the sugar beet are mainly determined by the plant production system, so we studied the effect of fertilization, irrigation and plant protection.