Where an acronym is used for an organisation then this will appear in the Organisations section.

  PSD : Particle Size Distribution.

  PSI : Pounds per Square Inch.

  PSPS : Pesticides Safety Precautions Scheme.

  PSR [1] : Pre-Season Rolling.

  PSR [2] : Pressure, State, Response.

  PTO : Power Take Off.

  PTT : Polytrimethylene terephthalate.

  PUWER : Provision and Use of Work Equipment Regulations 1998.

  QCF : Qualifications and Credit Framework.

  QoI : Quinone Outside Inhibitors, a fungicide group.

  RCD : Residual Current Device.

  REACH Regulation : Registration, Evaluation, Authorisation and Restriction of Chemicals Regulation.

  RFI : Request for Information.

  RFID : Radio Frequency Identifrication.

  RFP : Request for Proposal.

  RFQ : Request for Quotation.

  RFT : Request for Tender.

  RGR : Relative Growth Rate.

  RIDDOR : Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013.

  ROI : Return On Investment.