Stem Cell 2015;6(2) http://www.sciencepub.net/stem 1 Relation of Spraying Silicon with Fruiting of Keitte Mango Trees Growing Under Upper Egypt Conditions Abd El- Rahman, M.M.A. Hort. Dept. Fac. of Agric. South Valley Univ., Qena, Egypt E mail: montoaly@yahoo.com Abstract: This study was carried out during 2013 and 2014 seasons for examining the effect of spraying potassium silicate at 0.05 to 0.2 % applied once, twice or thrice on fruiting of Keitte mango trees. Foliar application of potassium silicate once, twice or thrice at 0.05 to 0.2% was accompanied with enhancing all growth characters, leaf pigments, N, P and K in the leaves, initial fruit setting %, fruit retention %, yield and fruit quality rather than non- application. The promotion was materially associated with increasing concentrations and frequencies of potassium silicate. A slight promotion on such parameters was observed with increasing concentrations form 0.1 to 0.2% and frequencies from twice to thrice. Carrying out two sprays of 0.1% potassium silicate at growth start and just after fruit setting was responsible for improving yield and fruit quality of Keitte mango trees grown under Upper Egypt condition. [Abd El- Rahman, M.M.A. Relation of Spraying Silicon with Fruiting of Keitte Mango Trees Growing Under Upper Egypt Conditions. Stem Cell 2015;6(2):1-5]. (ISSN 1545-4570). http://www.sciencepub.net . 1 Keywords: Keitte mango trees, potassium silicate, yield and fruit 1. Introduction Poor cropping is considered to be a serious and major problem that faces Keitte mango growers in Upper Egypt. There are many factors responsible for lowering yield such as unsuitable environmental conditions and malnutrition. Fruiting in such mango cv is obviously affected by various biotic and abiotic stresses. Various studies showed that using silicon was beneficial for counteracting the adverse effects of water stress on growth, nutritional status and fruiting of the plants (Epstein, 1999 and Matichenkov et al., 2000). It is also shown that silicon increases drought tolerance in plants by maintaining plant water balance, photosynthesis activity, erectness of leaves and structure of xylem vessels under higher transpiration rates. Also, it is responsible for encouraging water transport and root growth under unfavourable conditions and antioxidants defense system (Neumann and Zur- Nieden, 2011). Levitt (1980); Matickenkov et al. (2000); Ma and Takahashi (2002); Kanto (2002); Gad El- Kareem (2012); Ahmed et al. (2013a) and (2013b); Al- Wasfy (2013) ; El- Khawaga and Mansour (2014) and Ibrahim and Al- Wasfy (2014) mentioned that using silicon in all sources at 0.05 to 0.2% was accompanied with enhancing growth and fruiting of fruit crops. The goal of this study was examining the effect of various concentration and frequencies of potassium silicate on the yield and fruit quality of Keitte mango trees grown under Upper Egypt conditions. 2. Material and Methods This study was carried out during 2013 and 2014 seasons on 30 uniform in vigour 11- years old Keitte mango trees onto polyembryonic seedling mango rootstock and grown in sandy soil in a private orchard located at Qena district, Qena Governorate. The selected trees are planted at 5 x 5 meters apart. Drip irrigation system was followed. All the selected trees received the common horticultural practices that already applied in the orchard. Table (1) show the analysis of the tested soil (Chapman and Pratt, 1975). Table (1): Analysis of the testes soil Constituent Values Sand % 80.9 Silt % 10.0 Clay % 9.1 Texture grade Sandy pH (1: 2.5 extract) 7.95 EC (1: 2.5 extract ppm) mmhos/ cm o C 960 CaCO 3 % 5.1 O.M. % 0.8 Total N % 0.04 Available P (ppm) 1.3 Available K (ppm) 120 This study included the following ten treatments from different concentrations and frequencies of potassium silicate. 1- Control (sprayed with water trees).