Articles
THE INFLUENCE OF P-ITB (PHENYL INDOLE-3-THIOLOBUTYRATE), AN ARYL ESTER OF IBA, ON THE ROOTING OF ‘REDHAVEN’ PEACH
Twelve inch (30 cm) terminal, semihardwood cuttings of ‘Redhaven’ peach were collected on August 1, 1986, wounded on 2 sides of the base, and treated by dipping the base of the stem in a 95% ethanol solution of: 1) IBA, 2) P-ITB, or 3) a 1:1 (by wt) mixture of IBA + P-ITB.
Concentrations of IBA or P-ITB rooting aids used were 0, 2000, 4000, and 8000 ppm.
In the case of IBA + P-ITB mixture, 50% of the 2000, 4000, and 8000 ppm total conen was IBA; the remaining 50% was P-ITB. Treated cuttings were inserted in 3.5 x 3.5 inch plastic pots filled with No.2 vermiculite; placed under mist on a greenhouse bench and misted continuously for the first 24 hours.
For the next 2 weeks, cuttings were misted 4 sec/4 min; thereafter the mist cycle was 4 sec/8 min until termination of the study, 30 days after initiation.
The experiment was a randomized complete block; treatments were replicated 3 times with 12 cuttings per replicate.
All auxin treated cuttings rooted in higher percentages and developed more roots than corresponding control treatments (Tables 1, 2). Among the auxin treated cuttings, those dipped in IBA or a combination of IBA + P-ITB had a higher percentage rooted and more roots than those cuttings treated with only P-ITB. An optimum concentration for enhanced rooting appears to be either 4000 ppm IBA or 2000 ppm IBA + 2000 ppm P-ITB. P-ITB used alone did not appear to be a satisfactory substitute rooting compound for IBA with peach cuttings.