Effects of some humidity and IBA hormone dose applicatýons on rooting of M9 apple clonal rootstock Softwood top cuttings

In this study, softwood cuttings were taken from M9 dwarf apple rootstocks in early June. Different indole-3-butyric acid (IBA) concentrations [0 (control), 500, 1500, 2500 and 3500 ppm], different air humidity levels (85 - 90%, 95-100%) and rooting media of perlite effects on rooting capability and root formation of M9 apple rootstock cuttings were examined. All the cuttings remained alive. The highest ratio of cutting callus formation was found in control group (58%) in 95 - 100% humidity level and 2500 ppm IBA hormone dose application in 85 - 90% humidity level. The highest rooting ratio was obtained from control group (46%) in 95 - 100% humidity level; the lowest one was 3500 ppm IBA doseapplication (17%) in 85 - 90% relative humidity level. The highest rooting surface lenght was found in 1500 ppm hormone dose (0.53 cm) in 95 - 100% and 2500 ppm IBA dose application (0.42 cm) in 85 - 90% humidity level. With respect to root numbers, the highest value was from 1500 ppm IBA application (1.29 number/cutting) in 95 - 100% relative humidity, and 500 and 2500 ppm IBA doses (1.04 number/cutting) in 85 - 90% relative humidity level. The longest root was obtained from control group (2.03 cm) in 95 - 100% humidity level and 500 ppm IBA hormone dose (1.80 cm) in 85 - 90% humidity level. The shortest root was obtained from 2500 ppm IBA hormone dose  application (0.09 cm) in 85-90% humidity level. The highest root branching value was obtained from 1500 ppm hormone doseapplication (0.88 number/cutting) in 95 - 100% humidity level