ethanol to form a paste, then combined with lanolin (Fisher Scientific, Pittsburgh, Pa.) which was heated to a near-liquid state in a microwave. This paste was then placed into 50 mL syringes for ease of application. The etiolated stems were wounded by disrupting the cambial layer with sandpaper (wet/dry, 400 grade), and lanolin or lanolin with IBA was applied approximately 10 cm above the soil surface. After wounding and auxin application, the shoots were covered with 30 cm of fine pine shavings, contained in a 30 cm x 30 cm x 30 cm wooden box. The stooling box containing the pine shavings was irrigated as needed, and the mother plants were fertilized three times each summer via trickle irrigation with Peters 20-20-20 (N-P-K) water soluble fertilizer with micronutrients at about 1 oz of N/tree/year. Shoots were uncovered on November 4, 2002 to evaluate root initiation.
2003 Experiment The same nine plants used in 2002 were again cut back in early May 2003 to 10 cm and covered with 30 cm of fine pine shavings, contained in a wooden box to cause etiolation of the new shoots. The shoots were allowed to grow until they emerged from the shavings (approximately 40 cm), and treatments were then applied to the etiolated shoots on August 11, 2003. IBA treatment concentrations were increased over that applied in 2002 so that treatments included 0 IBA without wounding, 0 IBA with wounding; 5000 ppm IBA without wounding, 5000 ppm IBA with wounding; 10,000 ppm IBA without wounding, 10,000 ppm IBA with wounding, prepared in a lanolin paste and applied as described above. The shoots were uncovered on March 2, 2004 to examine for root initiation.
In the 2002 experiment, only one layered shoot, which was wounded and treated with 6000 ppm IBA, produced roots. This shoot produced two roots with an average length of 12 mm (Figure 4.2). Over 22% of shoots rotted, possibly due to frequent rainfall and an unknown fungal organism in the damp pine shavings. Several shoots were broken by wind damage caused by deep girdling of the stem. Those shoots that were not broken or rotting did continue to grow after treatments were applied. Since only one out of 84 shoots produced roots and the rooted shoot that was both wounded and treated with the highest concentration of IBA tested, 6,000 ppm, higher concentrations of IBA were applied to the shoots in an experiment the following year.