Seed potato growers have the off-label option of using the fungicide Shirlan (fluazinam) to control powdery scab this season, the Scottish Agricultural College has announced.

The Specific Off Label Approval relates to Shirlan applied at a maximum individual dose of 3 litres/ha as a tractor mounted downward directed drench in a minimum water volume of 200 litres/ha on the ridged bed prior to destoning or bed-tilling.

The SAC reminds any growers wishing to use the product to control powdery scab that they must obtain a copy of the SOLA and comply with its conditions, namely:

  • Approval is only for seed crops
  • If Shirlan is used for powdery scab, control products containing Shirlan should not be applied to the haulm for potato blight control
  • As with all SOLAs, growers using Shirlan for this purpose do so at their own risk

The SAC estimates that 75% of all varieties grown are judged to be susceptible or highly susceptible to powdery scab and until now, growers have not had the option of fungicide control.