Abstract
A sugar beet growth rate study was conducted in Alberta using a high root yield variety and a high sugar content variety. The objective of this study was to measure sugar beet root yield increases and sugar accumulation in both sugar beet varieties. Tests were conducted at 4 different locations between 2018 and 2021. Varieties were harvested approximately bi-weekly starting on July 15 and were measured for six consecutive treatment dates during the growing season ending in early October. Sugar loss to molasses was not measured due to instrumentation limitations for early harvest dates; therefore, sugar was referred to as gross sugar and not extractable sugar. For gross sugar per tonne and percent sugar, site years were analyzed separately due to an interaction that occurred between fixed and random factors. Root yield growth averaged approximately 340kgs/acre per day or 2.4 tonnes/acre per week for the high root yield variety and 310kgs/acre per day or 2.15 tonnes/acre per week for the high sugar content variety over the entire harvest period. Gross sugar per acre (GSA) increased 70kgs/acre per day or 492kgs/acre per week for the high root yield variety and 66kgs/acre per day or 460kgs/acre per week for the high sugar content variety. Gross sugar per tonne (GST) increased 1.0kgs/tonne per day or 6.9kgs/tonne per week for the high root yield variety and 1.2kgs/tonne per day or 8.1kgs/tonne per week for the high sugar content variety. Gross sugar per tonne was significantly (P<0.05) higher for the high root yield variety on the first harvest date, which was unexpected. On the second harvest date, the high sugar content variety had numerically higher GST. For the remaining 4 harvest dates, the high sugar content variety produced significantly (P<0.05) higher GST. This result provided strong evidence that the higher quality variety started slower but eventually surpassed the high root yield variety in quality. Maximum root yield and gross sugar per acre production occurred for both varieties between August 1 and August 14. Gross sugar per tonne and percent sugar accumulated the fastest between July 15 and July 31 for both varieties and slowed considerably between the second-last and last harvest dates. It was concluded that varieties vary in their sugar accumulation profiles over time and across multiple years.