Effect of lime concentrations on reduction of sugar and mass losses of sugar beet in storage

An experiment was conducted to evaluate the effect of lime application on the mass and sugar losses reduction from 2004 to 2005 in Karaj. Four lime concentrations of 0, 3, 4 and 5 percent (factor A) and storage durations of 30 and 60 days (factor B) were arranged as factorial experiment in RCBD with four replications. The commercial variety of Shirin was drilled in early May and storage roots were harvested late November each year. Weight and technical quality of beet samples such as sugar content, reducing sugar, sodium, potassium, amino-nitrogen, modulus of elasticity and root rot percentage were determined before and after each storage period. Air temperature inside the pile recorded daily using a max- min thermometer. Mean air temperature of silo in the first and second 30 days storage in year 2004 was 0.75 and 0.50 ºC greater than that in 2005, respectively. The results of combined ANOVA showed that effect of year was significant for mass loss, amino-nitrogen, dry matter content, reducing sugar (P<0.01), modulus of elasticity and root rot (P<0.05). Sugar losses, sugar content and amino-nitrogen in dry weight, molasses sugar, dry matter content and modulus of elasticity were affected significantly (P<0.01) by storage duration. Lime concentration had significant effect on modulus of elasticity (P<0.05) and sugar content in dry weight of sugar beet (P<0.08). There was no interaction between lime concentration and storage duration for sugar beet traits. Spraying lime concentration of 3 percent on the beet reduced root dehydration by 2 percentages and consequently modulus of elasticity increased by 0.39 MN/m2 in comparison with the check treatment. Although, sugar losses were not affected by lime application but sugar content (in dry weight) was 1.5 percentage more than and mass loss due to spraying lime concentration of 3 percentage was significantly less than both 4 and 5 percent concentrations. In conclusion, pre-washing sugar beet and then spraying lime with the concentration of 3 percentage before storage may reduce root dehydration and improve modulus of elasticity during the storage in conditions similar to theKaraj region.