EFFECT OF WATER IRRIGATION MANAGEMENT AND NITROGEN FERTILIZER SOURCES ON WATER PRODUCTIVITY AND QUALITY OF SOME EGYPTIAN COTTON CULTIVAR

The experimental field was conducted at the experimental farm, Fac. of Ag., Al-Azhar U., Assuit, during two growing summer seasons of 2018 and 2019. A field experiment was designed as randomized complete block with split split-plot arrangement of treatment with three replications. The current study aims to evaluate different irrigation methods (conventional and alternative furrows) and nitrogen fertilizer Sources (urea as fast nitrogen fertilizer and ureaform as slow one) for maximizing the production of some cotton varieties (G80 and G90) as well as to define the most favorable irrigation manner that achieves the highest water productivity and high cotton yield and its quality. The results showed that alternate furrow irrigation (AFI) saves about 12 % of the actual evapotranspiration (ETa) compared to the conventional furrow irrigation (CFI). The ETa increased with urea fertilizer compared to ureaform fertilizer. The estimated evapotranspiration (ETo) values in both growing seasons followed the descending order of FAO Penman-Montithe Turc Hargreaves. It is clear that the Hargreaves equation calculated ETo efficiently for cotton crop growth under Assiut region circumstances. The AFI increased the crop water productivity (CWP) and irrigation water productivity (IWP) by 13 and 15%, respectively compared to the CFI. The irrigation methods during both growing seasons had significant effects on cotton seed yield, cotton lint percentage, boll weight, lint index, seed index, 2.5% span length, length uniformity ratio, fiber strength (pressly index) and fiber fineness. The AFI realized positive higher effect on cotton traits and yield quality than those under (CFI).