Mineral nutrition of Cymbopogon nardus (L) Rendle: Part II. effects of magnesium and phosphorus nutrition on the fractional composition of essential oil

Abstract

Results obtained from a fertilizer experiment conducted with thirteentreatments indicate the positive effect of phosphorus and magnesium nutritionon the yield and the fractional composition of essential oil of Cymbopogonnardus. Phosphorus nutrition has increased the "total geraniol" (total acetylisablecompounds) in oil. Magnesium in combination with phosphorusfertilizers significantly increased the total geraniol at the second harvest. Theincrease of total geraniol was always accompanied by the decrease of totalhydrocarbons, which indicates the better utilization of monoterpenes in biosyntheisof constituents of total geraniol in oil as a result of phosphorus nitrition.Phosphorus content in leaves has positive relationships with total geraniol(r=+O.5), essential oil yield (r= +0.58) and output of total geraniol(r=+0.59). The optimum phosphorus concentrations in leaves after fourmonths of planting that produced maximum yields of essential oil and totalgeraniol by this crop were found to be in the range of 0.23-0.26 %.