Study of autumn sowing of sugar beet (Beta vulgaris L. ) in Fasa area

In order to determine the optimum sowing and harvesting dates of two autumn sugar beet cultivars (Bete vulgaris L.) and develop the planting area of this crop, the present research was conducted in Fasa, Iran during 2005-2008. The experiment was carried out in split-split plots based on randomized complete block design (RCBD) with four replications. Three sowing dates (September 27, October 17 and November 6) were assigned to main plots, two commercial sugar beet cultivars (BR1 and Rasoul) to sub- plots and three harvesting dates (April 30, May 26 and June 20) to sub-sub plots. During the growing period, parameters such as number of plants, lost plants, growth rate and bolting percentage were determined. The root yield was measured by harvesting the roots from the two middle rows of plots. Characteristics such as root yield, sugar content, impurities (K, Na and α-amino nitrogen) and white sugar percentage, purity of raw extract, alkalinity and molasses sugar were measured. Results showed that bolting percentages of sowing dates were significantly different at 1% level of probability. The highest bolting percentage (18.409%) was obtained from September 27 sowing date. Sowing dates (September 27 and November 6) had the lowest bolting percentage (5.420% and 2.870%, respectively). The bolting percentage, root yield, sugar content, impurities, and purity of raw extract, alkalinity, molasses sugar and white sugar yield of the cultivars were not significant. The maximum bolting percentage obtained from the harvesting date (June 20) was 9.964%. Maximum root yield and white sugar yield was obtained from the sowing date (September 27) and harvesting date (June 20) which were 58.486 and 5.360 tha-1, respectively. With respect to the increased yield due to planting date of September 27 and harvesting date of June 20, use of bolting tolerant cultivars to ensure higher quality and yield I recommended