estimation of root pulling force and measurement of root losses and soil transfer along with different root shapes of sugar beet

the root pulling force as well as the amount of transferred soil have not been reported quantitatively for various sugar beet types. this study was designed to measure the amounts of transferred soil from farm and estimate the root pulling force among sugar beets populations with different root shapes at harvest time. the experiment was conducted as a split plot with a randomized complete block design with four replications at motahari research station,karajin 2002 and 2003. main plots were allocated to soil moisture contents at harvest time and subplots to 7 sugar beet populations with smooth elliptic, conical and grooved conical root (normal beet) forms. sugar beets were compared at 40% soil water depletion in 2002 and at field capacity as well as 40 percents water depletion in 2003. broken roots were 8, 10 and 13% for smooth elliptic, conical and normal conical forms, respectively. percentages of broken roots in smooth elliptic and conical forms were 38 and 23 % less than the normal types, respectively. pulling forces in these forms were 59 and 52 % less than normal sugar beet, respectively. there were no significant differences for root and white sugar yield among different forms. however, lower losses, soil tare and pulling force of smooth conical roots makes them more preferable than the normal roots, for breeding purposes.