Laboratory and field testing of seed spacing uniformity for sugarbeet planters

Five planter configurations were evaluated for seed spacing uniformity at three field speeds using a seed location method in the field and a laboratory! method involving an opto-electronic sensor system. Planter seed spacing uniformity was described using the Coefficient of Precision (CP3) measure. Results showed that CP3 measures deter-mined using the laboratory test method were significantly different from those determined using the field test method. This indicated the laboratory test method cannot be used to predict planter seed spacing uniformity in the field. Seed spacing uniformity determined in laboratory tests was higher than, or equal to, seed spacing uniformity determined in field rests. This indicated the laboratory test method may be useful to screen out planters or planter units with poor uniformity of seed metering. Field testing of the planters that perform well in laboratory tests must be conducted to adequately determine the seed spacing uniformity of those planters in the field. Results from laboratory and field tests could be useful ill determining areas for improvement of planters or planter units.