Influence of Planting Spacing on Mechanical Properties of Eucalyptus grandis × E. urophylla Planted in China

The objective of this study was to understand influence of planting spacing on mechanical properties of Eucalyptus grandis × E. urophylla planted as a potential species for solid wood products in China. Four trees at age of 13 were selected from each of 6 groups of planting spacing and a total of 24 sampling trees were selected from the Dongmen Forestry Center of Guangxi Province in China. Furthermore, a one-meter-long log from each tree was cut into small blocks for wood properties testing. MOE, MOR and compression strength parallel to wood grain were determined in accordance with Chinese standards. In addition, wood density and shrinkage properties were measured. Statistical analysis by SAS software indicated significant differences among the 6 groups of planting spacings on the air-dried density, radial shrinkage and bending MOR properties at the 0.05 level, and also on the compression strength at the 0.10 level. However, it was observed that there is no significant differences among shrinkages in tangential and volume, and MOE.

赤桉、巨尾桉扦插育苗成活率试验

试验结果表明：不同浓度的ＡＢＴ生根粉液对扦插成活牵有显著影响，以２５０×１０－６ＡＢＴ生根粉液处理效果最好；扦插条硬枝、嫩枝对扦插成活率有影响，嫩枝扦插条成活率高于硬枝扦插；巨尾桉比赤桉更易扦插成活；扦插条有或无顶芽，对扦插成活影响不大；高温、高湿天气有利于扦插条成活。

应用不同浓度生根剂的巨尾桉扦插技术试验

以巨尾桉嫩枝为插穗,分别经吲哚丁酸和奈乙酸不同浓度溶液浸泡处理后,插入30%~100%持水量的基质,观察其成活率。结果表明,植物生长调节剂浓度为400~800 mg/L和基质持水量为田间持水量87%左右,能显著提高桉树扦插成活率;将2种植物生长调节剂混合使用,对插穗生根成活未产生抗药性,此外,扦插后的圃地管理也很重要。