الفهرس | Only 14 pages are availabe for public view |
Abstract The present study was carried out during 2011, 2012 and 2013 seasons to investigate the response of Balady mandarin trees productivity to natural minerals compound, organic and biofertilizers applications. This study was conducted in a private orchard located at EL Kalubia Governorate, Egypt. Twenty years old of Balady mandarin (citrus reticulata) trees budded on sour orange rootstock (citrus aurantium, L. Osbec) and planted at 5x5 meters a part under flood irrigation system, grown in a clay loamy soil were devoted for this investigation. This study was designed in two experiments : Experiment І . The investigation contained (three levels of compost ( 50, 75 and 100% ) from the amount of actual nitrogen required to mandarin tree three levels of (N.M.C) 4, 5 and 6 k.g /tree with biofertilizer and control. The obtained results cleared that application of (50% compost + biofertilizer + 6 or 5 k.g N.M.C) was the best combinations for giving maximum yield and improved fruit quality (increased fruit size, peel thickness, juice weight % , T.S.S/Acid ratio , V.C and decreased fruit acidity, fruit nitrite and nitrate contents ). Experiment І І . Three levels of compost (50, 75 and 100% from the amount of actual nitrogen required to mandarin tree) were used alone or with biofertilizer and with or without natural rocks (feldspar and phosphate rocks) one dose or two doses according the amount of actual K and P required to mandarin tree, respectively and control treatment. The obtained results cleared that application of (50% compost + biofertilizer + feldspar, phosphate rocks one dose) was the best combination for giving maximum yield and improved fruit quality (increased fruit size, peel thickness, juice weight %, T.S.S/acid ratio, V. C and decreased fruit acidity, fruit nitrite and nitrate contents). Also, all treatments enhanced of the soil biological activity in terms of increasing the total count bacteria (Bacillus circulans, Bacillus megaterium and Azotobacter chroococcum) comparing with the control treatment. it could be concluded that, organic fertilization has safety food and high fruit quality especially for reducing nitrite and nitrate in fruit juice which is considered as one of the main reasons causing harmful to human health. |