RESPONSE OF ROSELLE PLANTS TO VARIOUS LEVELS OF WATER AND NUTRIENTS GROWN IN SANDY SOILS

Field experiments were conducted during 2020 and 2021 seasons  at Aly Mobarak Experimental Farm, Horticulture Research Station" in El-Bustan area, Nubaria, El-Beheira Governorate to study the effect of various irrigation levels and NPK fertilizer rates using drip irrigation system on the vegetative growth, yield and quality of roselle plant (Hibiscus sabdariffa L.) grown in sandy soil. The experiment comprised of four drip irrigation levels (I1=60%, I2=80%, and I3=100% of crop evapotranspiration (ETc), in addition to control treatment (I4=120% ETc) which represented the growers practice in the area and four NPK fertilizer rates (F1=70%, F2=80%, F3=90% and F4=100% of the growers practice in the studied area) in a split plot design with three replications. The results revealed that both irrigation and NPK levels significantly affected growth parameters, yield and anthocyanin content of roselle plant. The highest values of dry yield of sepals were obtained with the highest irrigation treatment (120% ETc) which showed non-significant differences with the lower irrigation level (100% ETc) combined with the full NPK fertilizer rate (100%).  Maximum mean values of anthocyanin content were obtained with I1F3 treatment. Therefore, it could be concluded for maximizing dry sepal yield and quality of roselle plants as well as water use efficiency applying the irrigation treatment at 100% ETc combined with the highest NPK dose (I3F4) through fertigation at El-Bostan area.