RESPONSE OF KEITT MANGO TREES TO NITROGEN AND POTASSIUM FERTILIZATION UNDER NEW RECLAIMED LAND CONDITIONS

Abstract

Fatma Mohamed Abd-Alla: Response of Keitt Mango Trees to Nitrogen and Potassium Fertilization under New Reclaimed Land Conditions. Unpublished M.Sc., Department of Horticulture, Faculty of Agriculture, Ain Shams University, 2017. This study was carried out during three seasons 2013, 2014 & 2015 on four years old mango trees (Mangifera indica L.) Keitt cv. budded on seedling rootstocks planted at 2.5x 5.0 meter in sandy soil under drip irrigation system. The experiment was conducted at a private farm, newly reclaimed soil, located at Badr City, South Al-Tahrir, Al-Behaira Governorate, Egypt. The aim of this investigation was to find out the fertilization requirements and the best combination between organic nitrogen (chicken manure) & potassium (potassium sulphate) for achieving the optimum growth, yield, fruit quality and leaf mineral content of "Keitt "mango trees cultivated in sandy soil under newly reclaimed soil conditions, Egypt. This experiment involved three levels from nitrogen (250, 500 &750g N/tree/year) added as chicken manure and Potassium (250, 500 &750g K2O/ tree/year) from potassium sulphate. The treatments were arranged in a randomized complete block design (RCBD). The Result indicated that treatment T4 (500 g N as chicken manure + 250 g K2O as potassium sulphate /tree/year) gave the highest yield/tree, fruit weight, TSS, reducing sugars, leaf N, P, K, and Fe contents and the same treatment gave the lowest nitrate content in fruits. On the other hand, In addition, T6 (500 g N + 750 g K2O / tear / tree) reduced the alternate bearing index to the minimum value (3.42), opposite to T7 (87.60) control treatment T10 (500 g N as ammonium nitrate + 500 g K2O as potassium sulphate/tree/year) gave the lowest significant values for yield/tree, fruit weight, TSS, TSS/acid Ratio, leaf N, P, K and Zn, more over the highest nitrate content in fruits.