mg of IBA applied in the 20,000 ppm treatment. Therefore, the 10,000 ppm painted and 1,000 ppm wicking treatments had comparable amounts of actual IBA applied, whereas the 20,000 painted treatment had only about half as much IBA applied as the 5,000 ppm wicking treatment.
The shoots were uncovered and rooting data was collected on January 21, 2004. The bottomless pot and surrounding pine shavings were carefully removed from around the plants. Root number, length, and the number of rotted or dead shoots were recorded. 2003 grafted cultivar study
In a preliminary experiment to examine the effect of auxin concentration on rooting of shoots of grafted pawpaw trees treated with IBA delivered via wick, 36 pawpaw trees which had been chip-budded the previous year and stored at approximately 4circC in a walk-in cooler were selected. Eighteen of the trees had been chip-budded using PA-Golden, and the other 18 had been budded with Sunflower, both on seedling rootstocks. The trees were in 2 gallon TreePots. The scions were cut back to 3-4 buds and a 2-gallon RootTrainer which had had the bottom cut off was fit securely into the original pot and filled with fine pine shavings. Once the new shoots emerged through the surface of the sawdust, the bottomless pot and pine shavings were removed and treatments were applied.
The treatment structure was a 3 x 2 factorial, with the two factors being IBA concentration (0, 1,000 ppm and 5,000 ppm) and genotype. All shoots were wounded using sandpaper. This was a completely randomized experimental design, with 6 plants per treatment combination. Quick dip solutions were prepared at 1,000 ppm and 5,000 ppm using water-soluble IBA salts and placed in 1.5 ml microfuge tubes. A cheesecloth wick was submerged in the tube and wrapped and tied around the stem at the girdle. The tube and was covered with parafilm to reduce dispersion into the pine shavings and to tie the tube securely to the plant. After treatments were applied, the bottomless pot was replaced and shoots were re-covered with sawdust. The shoots were uncovered and data on root number, length, and shoot death and rotting was collected on January 21, 2004.
Based on preliminary data collected in the 2003 seedling study, an experiment with higher auxin concentrations and additional replicate plants was conducted in order to