Effect of plant density on harvesting quality of sugarbeet

Many studies have shown that the highest sugar beet yields and processing qualities are achieved with stands of at least 80,000 plants per hectare. Where heavy germination leads to the desired population being substantially exceeded, growers fear a loss in harvesting quality. For this reason, a two-year trial investigated the effect of the plant density on the performance of a standard six-row combine tanker harvester. Populations of about 50,000 and 80,000 plants per hectare with a large proportion of gaps and of 80,000 and 110,000 plants per hectare with few gaps were established. In addition, the effect of the lifting speed (1998: 3.5 and 5.5 km/h; 1999: 5 and 7 km/h) was examined. The performance of the combine tanker harvester was assessed for loss of whole beets and of broken tips and the quality of topping. The overwhelming proportion of the losses in both trial years arose from tip breakage. The topping quality differed in the two trial years. In the first year, about 50%, and in the second year, about 40% of the beets were properly topped. The results indicate that plant density does not substantially affect the quality of lifting. A high lifting speed tends to have a negative effect on lifter performance.