Effect of Fertilization with Mineral NPK and Spraying with Nano NPK on Growth, Yield and Quality of Onion

Two field experiments were conducted during 2018/2019 and 2019/2020 seasons at Shandaweel Agriculture Research Station, Sohag Governorate, to study the effect of different rates of mineral NPK fertilization under foliar application with Nano NPK, on vegetative growth, yield and quality of onion. Split plot design with three replicates was used. Mineral NPK fertilization rates occupied the main plots (100% NPK, 75% NPK, 50% NPK and 25% NPK), whereas Nano NPK spraying rates (control, 2 L/fed, 4 L/fed and 6 L/fed) occupied the sub plots. The obtained results could be summarized as follow: (i) Application of 100% NPK gave the highest values of plant height while, application of 25% of NPK gave the lowest values, in the two seasons; (ii) Spraying with Nano NPK at rate of 6 L /fed appeared the highest values of plant height, whilst, spraying with water (control treatment) appeared the lowest values; (iii) Application of 100% of mineral NPK gave the highest values of total yield, while, application of 25% of NPK gave lowest values in both seasons; (iv) Spraying with Nano NPK at rate of 6 L /fed appeared the highest values of total yield/fed, whilst, spraying with water (control treatment) appeared the lowest values, in the two seasons; (v) The highest values of total yield/fed were obtained by using 75% mineral fertilization and spraying with Nano NPK at rate of 6 L/fed, in both seasons; and (vi) The highest values of exportable bulbs yield were obtained by using 75% mineral fertilization and spraying with Nano NPK at rate of 6 L/fed., while, the lowest values were obtained by application of 25% of mineral NPK and spraying with water (control treatment), in both seasons.