Determination of water deficit sensibility in four stages of sugar beet growth

Water crisis as a main factor of agronomy limitation exists in all over the arid and semiarid area. Plant sensitivity to water stress in all of the growth stages is not similar. In order to calculate the crop sensitivity factor and water stress effect in different stages of sugar beet growth, the experiment was conducted in a completely randomized block design, on basis of split plot with four replications. Experiment was conducted in 2004 and 2005 in Hamedan province. Main factors consist of 4 different growth stages include 1) germination till establishment 2) establishment till %70-%80 canopy 3) full canopy 4) beginning of canopy decreasing till maximum extraction coefficient. Sub plots consist of different water consumption equal to %100, %85, %70 and %55 of evaporation replacing. The result of analysis showed that there was significant difference (¦Á = %1) between main plots in respect of sugar yield and white sugar yield. In respect of quality properties including sugar content and white sugar content have significant differences (¦Á = %1). There was a significant difference between the different levels of irrigation. But among non-sugar properties only alphaamino nitrate was significant (P¡Ü0.05).There was significant difference between irrigation different levels in root yield, sugar yield, white sugar yield and shoot yield(¦Á = %1). But there was not significant difference between in sugar properties and non sugar properties. But among non-sugar properties only alkalite was significant (P¡Ü0.05). Interaction effect of A and B factors was significant in root yield, sugar yield and white sugar yield (¦Á = %5). In sugar and non-sugar qualitative factors weren't significant. Yield response factor on the basis root yield in first, second, third and fourth growth stage was: 1.5, 1.1, 1.1 and 1.0 respectively. For sugar yield this factor was: 1.3, 1.0, 1.1,0.8 and for total growth stage for root and sugar was 0.8 and 1.1 respectively.