ABSTRACT
A 3 X 7 factorial experiment in split plot design was carried out at the Expt. Farm, Med. & Aroma. Plants Res. Dept., El-Kanater EI- Khaireya, Hort. Res. Inst., Agric. Res. Center during the two successive seasons of 2013/14 and 2014/15. The aim of study was to investigate the effect of NPK chemical fertilization (3 levels) and foliar spray of leaf extracts of Moringa oleifera and Aloe vera (7 levels) on growth and essential oil production of Pelargonium graveolens L. Herit plant, as well as evaluate to what extent can use natural leaf extracts as a substitute to NPK chemical fertilization.
Increases in herb yield per plant (g) and per fad (ton) as well as in essential oil yield per plant (ml) and per fad (l) were found as chemical fertilizer dose increased from 0 %, 50% up to 100 % of the recommended NPK dose (full dose) for pelargonium plant. Full fertilizer dose of 600 kg/ fad ammonium sulphate (20.5% N) + 300 kg/ fad calcium super phosphate (15.5% P2O5) + 150 kg/ fad potassium sulphate (48% K2O) resulted in the highest fresh herb and essential oil yields and this was associated with increasing N and protein percentages in dry herb.
Also, four foliar sprays during growing season with natural leaf extracts of moringa or aloe increased herb yield per plant and per fad and essential oil yield per plant and per fad. The highest fresh herb and essential oil yields were recorded in pelargonium plants sprayed with moringa leaf extract at 6 g/ L followed by sprayed plants with aloe gel leaf extract at 75 ml/ L.
When NPK chemical fertilizer interacted with foliar spray of leaf extracts of moringa or aloe, more increases in herb and essential oil yields were noticed. The combined treatment of full NPK recommended dose + spray of moringa leaf extract at 6 g/ L resulted significant increases in herb and oil yields as compare to those plants received full NPK recommended dose without any leaf extracts spray. Additionally, plants fertilized with 50 % of NPK dose (half-recommended dose) + foliar sprayed with moringa leaf extract at 6 g/ L produced herb and essential oil yields equal to or exceeded yields of fertilized plants with 100 % of the recommended NPK dose without leaf extract sprays.
In conclusion, it could be recommend that applying four foliar sprays with moringa leaf extract at concentration of 6 g extract/ liter combined with the half NPK recommended dose to reduce demand to NPK chemical fertilizers to half the recommended amount without adverse effects on pelargonium herb and essential oil yields.