El-Saady, A. S. M.and A. A. El-Abd( 2012). Effect of Balanced Fertilizer Splitting on Navel Orange Yield and Fruit QualityJ. Soil Sci. and Agric. Eng., Mansoura Univ., Vol. 3 (1): 41 - 51, 2012
Abstract: Three balanced fertilizer levels, L1 (495g N +101.5 g P+ 400 g K + 50 g S + 2.5 g Mg + micronutrients mixture ) of (300,150,100,50,50 mg kg-1 of Fe, Mn, Zn, Cu, B) ; L2 (990 g N + 203 g P+ 800 g K+ 50 g S+ 5g Mg + the previous micronutrients mixture and L3 (1485 g N+ 304.5g P +1200g K + 50g S+ 7.5g Mg + the previous micronutrients mixture compared to the farmer treatment (495 g N+ 101.5 g P) /tree/ year.Treatments were applied to mature navel orange trees which cultivated under the conditions of Metobas District, Kafr El-Sheikh Governorate, Egypt, during two successive seasons of 2007 - 2008 and 2008 – 2009. Randomized complete block design was used with four replicates (one tree = replicate). The three balanced fertilizer levels were divided into four splitting treatments (3, 6, 9 and 12 doses). The first and second treatments were added one dose / month. The third and fourth treatments were added one dose / 15 days. All treatments started at mid March in both seasons. The obtained results can summarized to:
The balanced fertilizer level (L3) had the highest values of chlorophyll A (89.9 and 94.1 μg/ cm2), chlorophyll B (71.8 and 75.7 μg/cm2), total chlorophyll (161.7 and 169.8 μg / cm2), nitrogen (2.62, and 2.62%), phosphorus (0.054 and0.057%) , potassium (1.67 and 2%), for leaves , fruit set (6.4, and 6.4%), fruit yield (138.2 and 133.5 kg/ tree/ year), soluble solid content (SSC ) (11.5% and 11.8%), acidity (0.98 and 0.97%), vitamin C (V.C) (57.8 and 56.7 mg /100 ml juice), reducing sugars (4.2, and 4.2%) and total sugars (7.4 and 7.3%) in the first and second seasons, respectively. While it had the lowest values for pre-harvest drop fruits (7.1 and 6.6%) in the first and second seasons, respectively. On contrary the lowest values of the mentioned parameters were recorded with the farmer treatment. In respect to fertilizer splitting the highest values of the previous parameters were obtained with the treatments splitted into 6 doses of balanced fertilizers.
Keywords: (Citrus, balanced fertilizer, splitting, navel orange, fruit quality.)
