Figure 9. The relationship stem water potential (MPa) and leaf δ13C isotope (‰) for ‘Honeycrisp‘ apple trees on B.9, M.9, G.969, CG.4292, G.210, G.87, CG.5257, G.814, G.890 rootstocks (P <0.001, r = 0.906). The line indicates the adjusted linear regression for the combined data points.