Evaluation of sowing and harvesting date effects on yield and quality of five sugar beet cultivars in Jiroft region (autumn planting)

As water is the most restrictive factor in national agricultural production, it is necessary to take decreased water consumption and increased water us efficiency in crop production into consideration. Nowadays, spring sugar beet production areas are concentrated in the region with water limitation and hence, the increase in spring production area contradicts the principle of water and soil conservation. Using new regions for autumn sugar beet sowing allows the increase in warm and semi-warm beet production areas. To develop sugar beet production in Province of Kerman and to find new climates, the study was conducted in Jiroft area in strip split split plots based on Randomized Complete Block Design (RCBD) with three replications during 2007-2008. Three sowing dates (September 6, October 7 and November 6), five cultivars (Rasoul, Monatuna, 9597, SBSI002 and SBSI003) and three harvesting dates (April 4, May 5 and June 5) were evaluated. Results showed significant effects of sowing and harvesting dates on white sugar yield. The effects of sowing date variations were greater than those of harvesting date so that growth period shortened by two months (due to delayed sowing date) decreased white sugar yield by 72.5% whereas and growth period prolonged by the same amount (due to delayed harvesting date) increased the white sugar yield by 55.1%. The highest white sugar yield (13.71 ton.ha-1) was obtained by early sowing (September 6) of SBSI002 and harvesting in May 5(with 240 days growth period). Considering favorable agro-climatic conditions in Jiroft region belonging to warm zone of Province of Kerman, it seems that the region has the potential for fall cultivation of sugar beet.