نقش كم آبياري كنترل شده بر كميت و كيفيت چغندرقند

Role of controlled deficit irrigation on sugar beet quantity and quality

The research was carried out to study the effect of Controlled Deficit Irrigation (CDI) on quality and quantity of sugar beet in Bardsir region of Kerman and Karaj during 2005- 2006. In this experiment, 11 irrigation treatments were studied in a randomized complete block design with three replicates. Crop water requirement was calculated in two- day periods. The treatments were implemented in different intervals (2, 3, 4, and 5 days) at three growth stages (vegetative development, root swelling and ripening). The irrigation system used was tape. After harvest, quantity and quality of sugar beet were determined and combined analysis was carried out for two years and two locations. To illustrate the relationship between the volume of water used as an independent variable and the measured traits as dependent variables, correlation coefficients were calculated and regression analysis was conducted. Irrigation treatments had significant effects (P< 0.05) on all traits except potassium, sodium and a-amines. Considering the root and sugar yield, WUE, sugar content, and Industrial Quality Index (IQI), the treatments T9 (medium water stress in development and ripening stages) and T10 (severe and medium water stress in ripening stage) were recommended. Total consumed water in the two above treatments Bardsir were 6840, 6944 and in Karaj were 7758, 7849 (m3ha-1) respectively which was about 23 percentage less than the water the applied. in T1 (control). These treatments were also the best in the combined analysis of each region. The results showed that water stress in root swelling stage was more effective on decrease of root yield than the other growth stages. The lowest WUE was observed for the treatments which had no water restriction or were exposed to the moderate deficit irrigation in different stages of plant growth (T1, T2, T3)