s.s. hemayati

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.

Autumn-sown sugar beet is an important strategy to produce sugar to meet domestic demand in Iran. New bolting resistant sugar beet cultivars can facilitate sowing sugar beet in autumn in warm and semi-warm areas in Iran. Therefore, a field experiment was conducted as split plot arrangement in randomized complete block design with four replications in Ardabil Agricultural and Natural Resources Research Center in 2008-2010 cropping seasons. Experimental factors included: three sowing dates (23 September, 12 October and 01 November), four harvest times (22 May, 22 June, 23 July and 23 August) and three cultivars (resistant, moderately resistant and sensitive). Results showed that cultivars were significantly different (P<0.05) for bolting rate. Sensitive cultivar with 89.75% bolting rate was significantly different from moderately resistant (41.78%) and resistant (12.23%) cultivars. Effect of sowing time on root, sugar and white sugar yields was not significant. Harvest time had significant (P<0.05) effect on white sugar yield and sugar content. Shifting of harvest time from 22 May to 22 June significantly increased sugar yield, white sugar and sugar content. Bolting resistant cultivar had higher root, sugar and white sugar yield than the other two cultivars. In conclusion, sowing of bolting resistant sugar beet cultivar in early November and harvesting in late June had the least bolting rate (1.32%), highest root (49.81tha-1), sugar (7.63tha-1) and white sugar (6.26 tha-1) yields in autumn sown sugar beet in Moghan region in Iran.

Monogerm and multigerm seed varieties are used in sugar beet cultivation. Singling is inevitable and mechanization almost impossible when multigerm seed varieties are used. For this and for some other reasons, economically sound and fully mechanized cultivation of sugar beet calls for the use of monogerm seed varieties. Throughout Europe, only monogerm varieties are used in sugar beet production. In sowing monogerm seeds, special types of machineries are implemented and land preparation techniques play a very important rule. In the past, lack of suitable machineries and well prepared lands discouraged farmers from sowing monogerm varieties and therefore, monogerm seed production showed no improvement in quality, quantity and diversity for many years. In recent years, with the growing interest of sugar beet producers, Sugar Beet Research Institute of Iran has focused on monogerm seed production. With the development of varieties suitable for different climatic areas, this institute has reached a high level of commercial success in monogerm seed production. In a multigerm seed production field, some fraction of the crop is monogerm. One way of monogerm seed production, called technical monogerm, is the separation of this fraction of monogerm seed from the multigerm seeds using a combination of round and slotted screens. Another type of monogerm seed is hybrid monogerm and its production is rather complex and requires special tools and material with a growing demand for monogerm seed, Sugar Beet Seed Research Institute has been focusing on the production and development of high quality basic seeds of monogerm type in recent years and the increasing level of commercial production of hybrid monogerm is a clear indication of its success. Table 1 shows the trend of commercial hybrid monogerm seed production in an interval of 5 years. Each year, field performances of domestic varieties are compared with top quality foreign varieties by researchers and technical staffs of SBSI, agricultural organizations and agricultural sectors of sugar refineries. Data gathered from 70 sugar beet production farms with a total of 203 hectares in Western Azerbaijan province for the production year of 2002 is shown in Table 2. At a large scale, average root yield is 5 tons per hectare with 9.01 tons of gross sugar. Domestic varieties show unique superiorities over foreign varieties and in some cases 40% yield increase is observed. Sugar Beet Seed Research Institute has developed Rhizomania and Nematode resistant lines and farmers will have access to the new varieties in the coming years.