In 1986 to 1989 trials were established aimed at making more concrete conception as in the range of fully utilizable row spacings by plants in a row (i.e. distance by which the plants are able to compensate through other yield-forming components without reduction in thc output), as on the effects of distances between plants not reaching this range. The Czechoslovak cultivar Domona was included in the trials. The study describes thc variants of the spacing 45 cm and the distance of plants in a row - thick sowing without singling after emerging - 10, 20, 30, 40, 50 and 100 cm. Only roots of maximum diameter over 5 cm were used to determine the quality and the yield of the harrow in the harvest. The yield results and qualitative parameters are presented in Tab. I. The highest sugar content and the percentage were found in the plant distance of 10 cm. Further reduction of distances led to marked decrease in sugar content. and thus to extract rate. Enlarging the distance of plants in the row resulted in even slighter decrease in these parameters. The conductometric ash content was the lowest in over-thick (without singling) stand and was increasing with larger distance of plants in the row. Significantly lower yields of thick stand without singling were found coincidently for the yield of roots, sugar and refined sugar in comparison with 20 cm distance and the thinnest stand as compared with variants of 10, 20, 30 and 40 cm distance of plants in the row. The other differences in the yields were insignificant. The studied range of variants was supplemented with logical onset, i.e. maximum density at which the plants do not pin the maximum required weight of 100 g. The yield of such stand is close to zero. In the scale of variables, supplemented in such a way, a pattern of dependences has been finding referred to sugar yield and refined sugar as well as on the distance of plants in the row (Fig. 1). This dependence is nonlinear and its trends are differing to a rather high degree in both sides from the top of the curve. The maximum sugar yield was found in the plant distance in the row of 23 cm and the refined sugar yield in the distance of the row of 20 cm. A graphical method was used to detect the limit distance of plants for appropriate per cent decreases of production (Tab. II). The maximum sugar yield (99 to 100 %) was obtained in the distances of plants in the row of 18 to 28 cm, the highest refined sugar yield being 16 to 26 cm distance, the decrease by 3 % was in the case of the distance 15 and 34 in sugar and 14 and 32 cm in refined sugar, 5 % and higher decrease in sugar yield was recorded in the distances of plants decreasing below 14 cm (i.e. 159,000 plants per 1 ha) and exceeding 38 cm (58,000 plants per 1 ha), for 95 % production of refined sugar - the limit values were 12 cm (185,000 of plants per 1 ha) and 38 cm. Knowledge of the effects of distance of plants and the space rate of the stand on the sugar beet yield enable in model of the arrganement of plants to make more accurate conceptions of production prerequisitions of sugar beet stands and eventually, yield estimations of this crop for which sometimes also a marked unequivalence or arrangement of plants in the row is a concomitant phenomenon of advanced technologies of their growing.
