Effect of nitrogen and potassium fertilization on nutritional status and fruit quality of citrus trees in case of converting irrigation system from flood to pressurized irrigation systems

Abstract EN

Two field experiments were conducted at Salheya area, Sharkia Governorate, Egypt during two seasons (2015 and 2016) to study the effect of N, K fertilization and irrigation systems on citrus trees (Citrus sinenis), in case of converting irrigation system from flood to pressurized irrigation systems.

Two N rates (800 and 1000g N/tree/year) and K (330 and 500 g K/tree/year) in the experiment 1 using 8 pressurized irrigation systems beside flood irrigation.

Three N rates (800, 1000 and 1200 g N/tree/year) and K (330,500 and 660 g K/tree/year) in experiment 2 under 6 irrigation systems using equal water amounts for all converted trees (25 mP3P/tree/year) by using small valves, and flood irrigation.

800 g N/tree/year and 330 g K/tree/year gave the highest N content in leaves in trees converted from flood to two lines dripper (S7), Highest K content in leaves was obtained by treatment of 1000 g N and 500 gK/tree/year under non converted trees (flood).

In experiment 1, highest content of total soluble solids (TSS) was obtained by 800 g N and 500 g K under trees converted from flood to Micro Jet in circle shape (S5), and the highest acidity pH was obtained by treatment of 1000 g N and 500 g K under trees converted from flood to S7.

In experiment 2 the highest N content in leaves was obtained by treatment of 1200 g N/tree/year and 660 g K/tree/year in converted trees to (S5) and the highest content of K in leaves was obtained by treatment of 1200 g N/tree/year and 330g K/tree in converted trees to T.

dripper in square shape (S4).

Application of 1000 g N/tree/year with 500 g K/ tree/year gave the highest percentage of TSS, and the highest percentage of total acidity was obtained due to adding of 1200 g N combined with 330 g K/tree/year in converted trees from flood to (S5).