The Effect of Spraying a mixture of micronutrients and Plant Growth Regulators on A vegetative growth the Chemical Contents and some physical characters for volatile oils of Lemon grass Plant (Cymbopogon citratus L.)

Abstract

A field experiment was conducted in the nursery of the Tikrit University/Faculty of Agriculture, the agricultural season 2013 on lemon grass plant. The Experiment was design with randomized complete block design (RCBD). the Experiment contained two factors, the first one is a mixture of some micro nutrients and three levels ; namely, non-spray treatment (T₀), spraying treatment with  50 mg.L^-1 Fe + 25 mg.L^-1 Cu +25 mg.L^-1 Zn (T₁), and spraying treatment with  100 mg.L^-1 Fe + 50 mg.L^-1 Cu +50 mg.L^-1 Zn (T₂). the second factor is plant Growth regulators with four levels first no plant Growth regulators labeled as (A₀), second, spraying in with IAA with concentration of 150 mg.L^-1. labeled as (A₁), spraying in with GA₃ with concentration of 150 mg.L^-1. labeled as (A₂) ,and spraying with mixture of IAA + GA₃ of 150 + 150  mg.L^-1 concentration labeled as (A₃) with three replications. the result showed that the treatment of (T₂A₃) spraying with mixture of micro nutrients and spraying with mixture of Auxin and Gibberellin significant differences in all of the characteristics of the vegetative growth. this resulted the plant height 162.41cm, number of leaves 52.87 leaf.plant^-1, leaf area  3665.19 cm², dry weight 173.09 gm.plant^-1, and leaf content of total chlorophyll   8.350 mg.gm^-1.

There were also significant differences amongst the treatments of the interference in the increase of concentrations of the nutrients in the leaves. the treatments (T₂A₃), (T₂A₂),and (T₂A₁) exceeded the other treatments and the non-adding treatment while there were no significant differences amongst the above mentioned treatments in some of the  concentrations of the nutrients. the interference treatment (T₂A₃) between the spraying with mixture of micro nutrients and spraying with mixture of (Auxin and  Gibberellin) resulted the highest concentration of nitrogen, phosphorus, potassium, magnesium, Iron, Copper, and zinc. the  concentration of these elements are 2.83 %, 0.390 %, 2.73 %, 0.892 mg.L^-1, 84.20 mg.L^-1, 17.73 mg.L^-1, 58.82 mg.L^-1 respectively. There are positive differences in the content 0f the volatile oil of the active compounds amongst the interference treatments. the treatments (T₂A₃), (T₂A₂), (T₂A₁), and (T₁A₃) resulted the highest content of the active compounds compared to the rest of the treatments and the non-adding treatment. there were no significant differences amongst the above mentioned treatments. the interference treatment (T₂A₃) between the spraying with mixture of micro nutrients and spraying with a mixture of (Auxine and Gibberellin) resulted the highest rate of percentage, Density oil, Specific gravity, and Refractive index 0.834, 0.858, 0.845, 1.263  respectively.