Magnesium Deficiency: The Cause of Spring Needle-tip Chlorosis in Young Pines on Pumice Soils

Authors: G.M. Will
Publication: New Zealand Journal of Forestry, Volume N.Z.J.For. 1966, Issue N.Z.J.For. 11(1) 1966, pp 88-94, May 1966
Publisher: New Zealand Institute of Forestry

Abstract: The surface layers of pumice ash in forests in the central region of the North Island, New Zealand, are low in magnesium. Until their roots have penetrated to deeper layers, trees are unable to obtain sufficient magnesium from the soil during the spring flush of growth, and become chlorotic. The chlorosis affects foliage carried over from the previous year; it is most marked when drought restricts uptake of nutrients from the topsoil, and when pruning has reduced the amounts of magnesium available for redistribution within the trees.