Physical and nutritional characteristics and performance after planting of Eucalyptus globulus Labill. seedlings from ten nurseries: implications for seedling specifications
2003
Close, D.C. | Bail, I. | Beadle, C.L. | Clasen, Q.C.
We measured the physical and nutritional characteristics of seedlings of Eucalyptus globulus Labill. (Tasmanian blue gum) in the nursery, and examined their effects on growth and mortality after planting in the field. Container-grown seedlings of widely varying specifications from ten nurseries were assessed immediately before planting. After planting, seedling height and collar diameter were recorded at monthly intervals for six months. Variation in seedling height, collar diameter, number of leaf pairs, visually estimated root development or foliar concentrations of P, K, S, Ca, Mg, Na, Cl, Fe, Mn, Zn, Cu, B and A1 did not account for observed height growth after planting. Seedling foliar N and (to a lesser extent) the size of the root ball largely explained the height growth observed after planting. The stems of seedlings with collar diameter ≤2.2 mm were susceptible to breakage. From this work, we recommend that nurseries producing E. globulus seedlings note the following points if they aim for optimal survival and performance of seedlings after planting on favourable sites: • foliar N is a good indicator of potential early growth after planting, and concentrations of 15-20 g kg-1 are associated with best field performance; • average seedling collar diameters ≥2.3 mm seem to prevent breakage of the stem of seedlings of a height typically produced by nurseries (180-270 mm).
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