Study on water productivity and yield simulation of autumn-sown sugar beet in Khorasane Razavi province- Case study of Torbate-jam region

Sugar beet is a biennial crop that is possible to cultivate at autumn in some region and harvest it at the next spring year. This research was conducted to study the possibility, appropriate cultivars, water consumption and water productivity of autumn sowing sugar beet in Torbate-e-Jam city (2010-2012). For this purpose a three factor randomized complete block design with the treatments arranged in strips was done at two sugar beet planting dates as horizontal factor (23 Sept. and 23 Oct.), six cultivars as vertical factor (consist of Iranian and foreign cultivars) and two harvesting dates as subplot factor (22 May and 22 June) in the farm of Jam sugar beet factory. The results showed that there was a significant difference between sowing dates of sugar beet at 23 Sept. and 23 Oct. The sooner sowing would cause increasing in yield and amount of boulting. There were observed differences between cultivars for root yield, sugar yield and boulting percentage. The most root yield and the least boulting amount was belong to Giada and Monatuno cultivars. There was also significant difference between harvesting dates. In general, the sooner harvesting would cause decreasing in root and sugar yield. On the basis of this research it is possible to plant the autumn-sownn sugar beet in the Torbat-e-Jam region. In this condition, average root yield was about 47.3 ton/ha and the maximum root yield was 76.9 ton/ha. The average and maximum sugar content were 14.9 and 18.7 respectively. Also, the average of bolting amount in resistant and sensitive cultivars were 2% and 75% respectively. Autumn sownin sugar beet in Torbat-e-Jam region related to plating and harvesting dates, required 5 to 7 times irrigation with 10000 cubic meter per hectar of water consumption. In this region, spring sugar beet was irrigated 20 times averagely with 20000 m3/ha water consumption. Therefor it is expected to autumn-sown sugar beet decrease irrigation water consumption 50%. Water use efficiency of spring sugar beet was 3.2 kg/m3 and for autumn sugar beet was 4.7 kg/m3 that increase about 45%. Development of autumn sugar beet cultivation in the Torbat-e-Jam region is expected to decrease 30 milion cubic meter extraction of ground water resources. It is mean compensating about 23% of deficit in ground water reservoir of critical Fariman-Torbatejam plain. In conclusion, considering to best conditions of yield and water use efficiency, sowing date at 23 Octeber and harvesting date at 22 June is recommended for Jam region.