云南松苗木生长对追肥和IBA叶面喷施的响应

采用L₉(3⁴)正交设计（增加1个对照），进行根博士追肥和IBA叶面喷施对云南松苗木生长影响的试验。苗龄45 d时开始第1次追肥和叶面喷施激素。分别于苗龄90、135、180 d与225 d时测定其地径和苗高，255 d时测定主根长和一级侧根数。结果表明，苗龄225 d时，平均地径和苗高分别为1.46~2.02 mm和4.5~5.2 cm，测定时，主根长和一级侧根数分别为21.7~31.1 cm和8~12条·株^-1。除135 d和225 d外，其余各阶段地径与苗高均呈现极显著差异（P<0.01）。影响地径和主根长的主导因子是追肥频率，苗高和一级侧根数的则是根博士浓度；侧根与苗高协同生长，主根长与地径生长呈正相关。30 d追施1次300倍的根博士溶液与叶面喷施0.15 g·L^-1IBA溶液的组合促进苗木生长。试验根博士与IBA配合应用可防止云南松产生蹲苗现象。

Response of Pinus yunnanensis Seedling Growth to Topdressing and IBA Foliar Spraying

The L₉(3⁴) orthogonal design (with 1 control) was applied to examine the effects of topdressing (a fertilizer “Dr.-Root”) and IBA foliar spraying on the growth of Pinus yunnanensis seedlings.The first topdressing and foliar hormone application began at the day when seedlings were 45 days old.Basal diameter (BD) and seedling height (SH) were measured when the seedlings were 90,135,180 and 225 days old,and taproot length (TRL) and numbers first-order lateral root (NFOLR) were measured when the seedlings were 255 days old.The results showed that the mean BD and SH were 1.46-2.02 mm and 4.5-5.2 cm,respectively for 225-day-old seedlings,and mean TRL and NFOLR were 21.7-31.1 cm and 8-12 roots/seedling for 255-day-old seedlings,respectively.Except for 135 and 225-day-old seedlings,there were significant differences in BD and SH between other seedling-age stages (P<0.01).The dominant factor affecting the BD and TRL was topdressing frequency,while SH and NFOLR were dominated by the concentration of topdressing fertilizer.The growth of first-order lateral root and SH displayed coordinated characteristics,while the growth of taproot and BD presented positive correlation.The seedling growth was promoted by topdressing 300 times of “Dr.-Root” solution and spraying 0.15 g·L^-1 IBA solution on the leaf surface once every 30 days.It was concluded that the application of “Dr.-Root” combined with IBA could prevent phenomenon emergence of grass stage when cultivating P.yunnanensis seedlings.