Effects of Ascophyllum nodosum extract application in the nursery on root growth of containerized white spruce seedlings

MacDonald, J. E., Hacking, J., Weng, Y. and Norrie, J. 2013. Effects of Ascophyllum nodosum extract application in the nursery on root growth of containerized white spruce seedlings. Can. J. Plant Sci. 93: 735-739. In this preliminary study, Picea glauca seedlings were root drenched with a commercial liquid extract of Ascophyllum nodosum in finisher fertilizer (8N-20P-30K) at the following rates: 1:500, 1:250, 1:125, and 1:75. Fertilizer alone served as control. Applications were made four or eight times over a period of 17 or 43 days, respectively. Compared with control, all rates reduced total root system length in mid October by 44-54%. After freezer storage and then growing under favorable conditions in spring for 21 d, the 1:125 and 1:75 rates increased the number of white roots emerging from the intact peat plug by 42 and 63%, respectively.