| Abbreviation | Definition |
|---|---|
| RIMM | Resonance Interference and Microwave Method |
| RIVI | RIbes VIscosissimum (sticky currant) |
| RL | Regular Leaf |
| RL | Root To Leaf |
| RLS | Root Lateral Spread |
| RNAI | RiboNucleic Acid Interference |
| RPM | Rapid Plant Matrix |
| RPSS | Registry of Professional Soil Scientists |
| RPUA | Residious Plastic Agrarian Use |
| RRCB | Roundup Resistant Creeping Bentgrass |
| RSP | Random Selection Process |
| RSPL | Red Sweet Potato Leaf |
| RSPM | Regional Standards for Phytosanitary Measures |
| RT | Root Tail |
| RTA | Root The Area |
| RTEP | Root and Tuber Expansion Programme |
| RTFA | Real Time Flower Auction |
| RZ | Root Zone |
| RZB | Root Zone Banding |
| RZD | Root Zone Depth |