GROWTH AND MINERAL NUTRITION IN SEEDLINGS OF AUSTRALIAN CEDAR (Toona ciliata) SUBJECTED TO NUTRIENT DEPRIVATION

In order to evaluate nutritional requirements and the effect of nutrient deprivation on the development of seedlings of Australian cedar (Toona ciliata M Roem var australis), a greenhouse experiment was conducted. The substrate used was a dystroferric red latosol with low nutrient availability using 15 treatments and applying the missing element technique. The experiment included two complete treatments (one provided N, P, K, S, B, Cu, Zn with limestone while another provided N, P K, Ca, Mg, S, B, Cu and Zn without limestone), besides deprivation of each nutrient (-N, -P -K, -Cu, -Mg, -S, -B, -Cu and -Zn), one treatment with coin deprivation of B, Cu and Zn, one treatment applying limestone only one treatment applying N, p, K. S. B, Cu and Zn, without limestone, and one absolute control treatment (natural soil). The following characteristics were evaluated: height, diameter shoot dry matter and root dry matter and nutrient content in the shoot do; matter after 150 days. Australian cedar plants have high nutritional requirements, and nutrients P, N, S. Ca, K, Mg and Cu, in that order were found to be limiting factors to plant development. B and Zn deprivation did not affect plant development. Limestone application was essential for the development of Australian cedar plants. Initial deficiency symptoms were found to he the result of S. limestone and N deprivation.