Optimum sample size of sugar beet roots for determination sugar content

Determination of an optimum sample size for the evaluation of sugar beet quality is of vital importance. A desirable sugar beet sample could represent confidently the sugar content and quality of delivered beets to the sugar factories. This experiment was carried out at Research Station of Kamalshahr, Karadj, Iran. The experimental field was about 2000 m2 with the distance between rows and plants being 60 and 20 cm, respectively. A triploid multigerm variety (IC1) was used in this study. During the growth period, 180 kg/ha nitrogen was utilized at two times. Half of N was applied pre sowing and half of N as the top dress. The experiment was conducted by controlling disease, pests, and irrigation. Treatments included pulps of n1=5 to n16=80 roots as: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 roots after harvest. Pulps were supplied for each treatment and then chemically analyzed. The results showed that for a proper evaluation of sugar content in semiarid regions like Karaj, a minimum of 65 beet roots is required to limit the sugar content fluctuation. Therefore, for an accurate estimation of sugar content of a heterogenus varietiy such as IC1, at least 65 beet roots might be considered to represent a real sample of a sugar beet population.