Effect of phosphate fertilization on trace element nutrition of Pinus pinaster grown in a sandy acid soil

In the past 30 years, phosphate fertilization has been widely used by foresters in Landes de Gascogne. During this same period, several growth disturbances and malformations without pathological affections have appeared in pines and particularly in 3 yr old pines (twisting of branches and leaders, abundant fascicle shoots, loss of apical dominance, die-back of the top and production of unlignified tissues). The symptoms are similar to those described for other coniferous species in copperor boron-deficiency conditions. The similarity of the symptoms and the very low trace-element contents in these sandy acid soils were consistent with a possible problem of micronutrient nutrition.