Production of Yellow Cortez (Tabebuia serratifolia) Seedlings in Response to Nitrogen Fertilization

ABSTRACT This work aimed to evaluate the effect of sources of nitrogen and respective levels on growth and quality of Yellow Cortez (Tabebuia serratifolia) seedlings. Seedlings were grown on a Oxisol and nitrogen sources were ammonium nitrate, ammonium sulphate and calcium nitrate, applied in five doses (0, 75, 150, 225 and 300 mg dm–3) and increments of 25, 50, 75 and 100 days after transplanting. The experimental design was randomized in blocks in factorial scheme (3 × 5) with four replications. At 125 days after transplanting, the addition of nitrogen provided significant effect on seedling production of Yellow Cortez (Tabebuia serratifolia), and the ammonium sulfate produced the best means for all traits and indexes evaluated. We recommend the use of ammonium sulfate at a dose of 100 mg dm–3 N for Yellow Cortez seedling.摘要 本研究旨在探究氮源及其施用水平对黄科尔特兹（Yellow Cortez，Tabebuia serratifolia）幼苗生长与品质的影响。试验以氧化土（Oxisol）为栽培基质，供试氮源涵盖硝酸铵、硫酸铵与硝酸钙，设置5个施氮剂量（0、75、150、225和300 mg dm–3），并分别于移栽后25、50、75和100 d分次施加。试验采用3×5因子设计的随机完全区组方案，设置4次重复。移栽后125 d时，施氮处理对黄科尔特兹幼苗的育苗成效具有显著影响，其中硫酸铵在所有被测性状与指标中均表现最优。本研究推荐以100 mg dm–3的施氮量施用硫酸铵，用于黄科尔特兹幼苗培育。