Improved crop yields are obtained by determining total dissolved solids (TDS) in a representative sample of transplants to determine strike rate as a logarithmic function of TDS before transplanting. Juvenile plants with high strike rate readings are transplanted. A refractometer having a logarithmic scale showing Low medium and high strike rates as a direct readout from a juice sample is used. A bioregulator can be used to induce high TDS Levels prior to transplanting. Particular application is to transplanting strawberry runners.