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The physical characteristics of a container growing medium containing 2 oak sawdust composted with poultry manure: 1 vermiculite: 1 perlite were compared with those of a similar medium containing sphagnum peat rather than compost. Both media were amended with inorganic nutrients based on laboratory analysis to make them nutritionally comparable and with AquaGro wetting agent at 800 g·m–3. Moisture release characteristics of the media were evaluated using tension cups in which desorption at 5, 10, 20, 40, 80, 100, and 160 cm of water was measured. While bulk density of the peat mix (0.129 g·cm–3) was, significantly lower than that of the compost mix (0.157 g·cm–3), total porosity of the peat mix (84%) was significantly greater than that of the compost mix (79%). Air-filled and water-filled porosities of the peat and compost mixes were 18.2% 16.2% and 75.2% 70.5% of container volume, respectively. While the peat mix held more water at tensions between 5 and 20 cm, there was no significant difference between the volumetric water contents of the two media between 20 and 160 cm. Fresh and dry weights of corn plants grown for 3 weeks in compost- and peat-based media were not significantly different.
Abstract
In vitro propagated shoots of the apple rootstock, Antonovka 313 (Malus pumila Mill.)9 were rooted successfully in vitro. Roots became visible in 6-8 days, and 100% rooting after 2 weeks was achieved consistently in shoots cultured on modified Murashige and Skoog (MS) salt medium supplemented with 0.25 μm indole-3-butyric acid (IBA). Sucrose was the most influential medium component for rhizogenesis. Inorganic nutrients, IBA and vitamins did not influence rooting. Omitting activated charcoal caused only a slight decrease. A 1.5% sucrose solution added to a peat-vermiculite growing medium in vitro resulted in higher rooting than in treatments without sucrose.
Abstract
Succulent branch terminal cuttings of Douglas-fir [Pseudotsuga menziesii (Mirb) Franco] placed horizontally (adaxial side up) curved slightly. Cuttings placed vertically, horizontally (adaxial side down), or on a horizontal clinostat exhibited significant adaxial-convex curvature. The response is regulated, in part, by substances exported from the needles and terminal bud. Gibberellic acid (GA3), (2-chloro-ethyl)phosphoric acid (ethephon), amino-ethoxyvinylglycine (AVG), indolebutyric acid (IBA), triiodobenzoic acid (TIBA), and 6-benzylamino purine (BA) failed to affect the curvature of vertically placed shoots.