EFFECT OF SOIL FERTILIZATION ON VEGETATIVE GROWTH, YIELD AND LEAF NUTRIENT COMPOSITION OF SULTANI FIG TREES

Field experiment was conducted during 1985 and 1986 using sultani fig trees grown in Sidi Krare orchard (about 30 km west of Alexandria, Egypt). Eight fertilization treatments were as follows: 1. Control (without fertilization). 2. 1 kg super phosphate (15% P2O5) + 1 kg potassium sulphate (48-50% K2O)/tree. 3. 1 kg super phosphate + 1 kg potassium sulphate + 0.5 kg N/tree (from commercial urea 46.5% N). 4. 1 kg super phosphate + 1 kg potassium sulphate + 0.5 kg N/tree (from urea forte 46.5% N + micro nutrients). 5. 1 kg super phosphate + 1 kg potassium sulphate + 0.5 kg N/tree (from ammonium sulphate 21% N). 6. 1 kg super phosphate + 1 kg potassium sulphate + 1.5 kg N/tree (from commercial urea). 7. 1 kg super phosphate + 1 kg potassium sulphate + 1.5 kg N/tree (from urea forte). 8. 1 kg super phosphate + 1 kg potassium sulphate + 1.5 kg N/tree (from ammonium sulphate). Applying 1.5 kg N from commercial urea to fig trees significantly increased the yield per tree than those of 1st, 4th, 5th and 8th treatments in 1985 and 1986. The higher level of nitrogen (1.5 kg) from different sources of fertilizers and lower level (0.5 kg) from ammonium sulphate significantly decreased TSS as compared with other treatments in 1985, whereas in 1986 the higher values were obtained from adding 0.5 kg and 1.5 kg N from urea forte (4th and 7th treatments). In general, nitrogen fertilization from different sources increased acidity as compared with those of 1st and 2nd treatments.