ANNUAL INCREMENT GROWTH IMPROVEMENT OF Swietenia mahagoni AS EFFECTED BY USING NPK FERTILIZER IN THE NEW RECLAIMED LANDS.

In this investigate conducted during period of 2008 to 2011 to study the effect of  NPK fertilizer on annual increment rate for growth of Swietenia mahagoni, Fam. Meliaceae. The trees were at the age seven years old, which have been planted at a distance of 3mx3m in new reclaimed land, north west of Cairo, Egypt, at the Experimental Farm of Aly Moubarak Hort. Res. Inst. Agric. Res. Center (ARC).  They were fertilized with ammonium sulphate (15.5% N) at the rates of N1 = 0.0, N2 = 51.61 and N3 = 103.22 g, superphosphate (40-46% P2O5) at the rates of P1 = 0.0, P2 = 64.51 and P3 = 129.03 g and potassium sulphate (50% K2O) at the rates of K1 = 0.0, K2 = 16.00 and K3 = 32.00 g all per tree, which they were 27 treatments. The best treatments which were more effective in annual rate increment for height (ARIH) were K1N2P3 and K2N2P1 (88.333 and 83.333 cm) in the first year and K3N1P3 (83.333 cm) in the second year of fertilization. The treatment of K3N2P2 caused the high value of annual rate increment for diameter at breast height (ARIDBH) which was (3.040 cm) and high value of annual rate increment for Basal area (ARIBA) which was(56.970 cm2)  in the first year of fertilization, while, in the second one K2N3P3 treatment produced high value of BAAI (56.843 cm2). However, in the third year of fertilization there was no significant effect of NPK fertilizers on the previous measurements, in addition to in many treatments fertilization  lead to an adverse effect on these measurements.