Root electrolyte leakage and root growth potential as indicators of spruce and larch establishment

The relationship between the condition of bare-rooted 2-year-old seedlings of Sitka spruce and larch at the time of planting and their survival and growth after 2 years was examined. Data were analysed for 2 experiments using seedlings lifted and stored at +1 °C throughout the winter for planting in April and also for 2 experiments using seedlings planted directly on different dates without cold storage. Electrolyte leakage from the fine roots of spruce was closely correlated to survival following direct planting at different times from September to April and fine root leakage was a more accurate indicator of spruce performance than root growth potential. However the pattern of larch survival of directly planted stock was more closely related to root growth potential than to root leakage. When seedlings were cold-stored, root electrolyte leakage and root growth potential were modified during storage and following cold storage, the performance of both species was more closely related to root electrolyte leakage than root growth potential. These results are interpreted as meaning that successful establishment of bare-rooted seedlings requires a functional nursery root system that is capable of both supplying adequate water for a limited period immediately after transplanting and of producing roots to meet the seedlingâs increased water demand later in the growing season.