Postharvest Losses Associated with Severity of Rhizoctonia Crown and Root Rot of Sugarbeet at Harvest

To investigate the effect of Rhizoctonia crown and root rot (RCRR) on postharvest storage properties, roots with similar symptoms (based upon a 0 = no rot to 7 = 100% rotted scale) were grouped together and extractable sucrose, invert sugar, and respiration rate were determined 30 and 90 days after harvest (DAH). The respiration rate of roots 30 DAH with ratings of three, four, and five was 22, 92, and 213%, respectively, greater than roots with a two rating; 90DAH respiration rate increases of 17, 84, and 201% were associated with ratings of three, four and five. The extractable sucrose concentration 30 DAH of roots with ratings of three, four, and five was 4, 14, and 29% less than roots with a two rating. Compared to roots with a two rating, 90-DAH decreases in extractable sucrose concentration of 4, 16, and 35% were associated with ratings of three, four and five. Invert sugar concentrations of roots with ratings of four and five were 3.3 and 10.8 times the concentration of roots with a three rating, 30 DAH. Roots with ratings of four and five had 6.6 and 26.1 times the invert sugar of roots with a three rating 90 DAH.