effect of different tillage methods in monogerm seedbed preparation on yield and quality of sugar beet

the aim of this study was to investigate the effect of tillage methods to obtain suitable seedbed for monogerm seed. therefore, a split plot experiment based on a randomized complete block design (rcbd) with three replicatians was conducted at darab station of fars province. the main plot was seedbed prepration at two levels including fall and spring season. subplot included 1) moldboard plow at depth of 30-35 cm + disk; 2) moldboard plow at depth of 30-35 cm + rototiller; 3) chisel plow at depth of 30-35 cm + disk; 4) chisel plow at depth of 30-35 cm + rototiller; 5) subsoiler at depth of 30-35 cm + moldboard plow at depth of 25-30 cm + disk; 6) subsoiler at depth 30-35 cm + moldboard plow at depth of 25-30 cm + rototiller. parameters such as soil bulk density, soil cone index, percentage of germination, germination rate index, and yield and quality were measured. the results indicated that the effect of using tillage implement in fall season on bulk density and cone index was significantly different from that of spring season. percentage of germination, germination rate index and yield increased by using the tillage implements in fall compared with spring season. results indicated that three factors including application time, tillage implements and depth can be effective on the measured parameters. moldboard plow at depth of 30-35 cm in fall season along with rototiller produced higher percentage of germination (94.42%), germination rate index(4.93%), purity (82.68%), root yield (81.81 tha-1) and while sugar beet.