Effect of pyraclostrobin on postharvest storage and quality of sugarbeet harvested before and after a frost.

Pyraclostrobin and other strobilurin fungicides have been reported to have beneficial effects on productivity that cannot be attributed to disease control. Enhanced frost tolerance is one such effect that has been observed for sugarbeet (Beta vulgarisL.) after a late season foliar pyraclostrobin application. This phenomenon has been reported in some, but not all, sugarbeet trials, and may potentially affect root storage properties, especially when roots are harvested after a frost. Research was conducted to determine the effect of late season pyraclostrobin application on storage properties of roots harvested before and after a frost. The effects of pyraclostrobin on postharvest respiration rate, invert sugar and raffinose concentration were variable across environments and time in storage, and there were no apparent relationships between the storage properties measured. However, foliar applied pyraclostrobin resulted in a small (3.7 kg Mg -1 ) but significant increase in average extractable sucrose concentration compared to no pyraclostrobin control treatments. This increase was observed in roots harvested before and after a damaging frost after storage for 0 or 90 days.