LIST OF TABLES Data collection scheme for the study of the. macromorphology and quantity of plant material at different ages Characteristics of living stems in plant material of different ages Percentage of living stems with emerged roots and/or buds and/or three leaves on one node in plant material of different ages Correlations among morphological characteristics of stems in 4-week-old plant material. . Correlations among morphological characteristics of stems in 7-week-old plant material Correlations among morphological characteristics of stems in 12-week-old plant material Macromorphological stem classes were defined in plant material of i, 7 and 12 weeks. Large differences were found in mortality, leaf growth and root development between cuttings from different classes of stems. Development after planting was pcsiti\ely related to maximum xiii stem diameter, emergence of roots and other stem characteristics, which distinguished the stem classes. Thick stems were much superior to thin stems as propagating material under all growing conditions tested. The stem section from which cuttings were derived influenced development also. Stems with two or less nodes and diameters less than 1.3 mm developed slowly after planting even under optimum soil moisture. These stems comprised 75% of the stems, 42% cf the weight and 64% of the nodes of 4week-old plant material. Stems with diameters less than 1.6 mm and without emerged buds or roots comprised 60% of the stems, 30% of the weight and 50% of the nodes of 7-week-old plant material. Stems with diameters of 1.6 mm or larger accounted for 20% of the stems, 50% of the weight and 30% of the nodes of this material. Stems with diameters less than 1.6 mm and without emerged buds or roots comprised 25% of the 12-week-old plant material. Stems with a maximum diameter between 1.6 and 2.1 mm comprised another 25% of this material. The remainder of the material consisted of approximately equal parts of stems with diameters less than 1.3 mm or larger than 2,1 imn. Submergence of cuttings for one minute in 1000 ppm Ethrel increased root weight on mist-grown cuttings. Thirty to 100 ppm Ethrel increased weight of field-grown plants. Cuttings treated w'ith 3000 or 10,000 ppm Ethrel developed less well than untreated cuttings. Ethrel treatment effects were observed on five different plant materials. Maximum positive responses were observed in three of these materials from Ethrel xiv levels of 300 and 1000 ppm. These levels gave negative responses in the other two materials. Initially the propagule stems were integral parts of the new plants and were the only tissue connecting roots and leaves. The growth phase in which this condition prevailed was, however, invariably a short term one (about 6 weeks). Later, new rooted shoots developed from axillary buds. At that point, the propagule stem lost its significance as part of the new plant. XV CHAPTER 1