This experiment was carried out in the open field at the Experimental Farm of Horticulture Department,
Faculty of Agriculture, Benha University, Egypt, during two successive seasons 2013-2014 and 2014-2015 to
investigate the effect of mineral fertilizers NPK at the rate of 50 kg N/feddan (one feddan=0.42ha) as urea,
25 kg P O /feddan as calcium superphosphate and 40 kg K O/feddan as potassium sulphate (as full dose) and 2 5 2
effective microorganisms (EM) at 30 ml/plant (as biofertilizer), as well as Zeolite at the rate of 48.2 kg/feddan
(as full dose) and their combination on growth, flowering, yield of volatile oil of violet (Viola odorata L. )
plants. The results showed that, the vegetative growth, flowering characteristics, as well as yield of concrete
of leaves and flowers and its volatile oil composition of violet were favorably affected by different fertilization
treatments either full doses of chemical fertilization, biofertilization (EM) or Zeolite separately or in combination
with them. The combined treatments of EM at 30 ml/plant + 75 % dose NPK or full dose of NPK gave higher
values in both seasons for most characters (number of leaves, fresh and dry weight of leaves, number of
flowers, fresh and dry weight of flowers leaves and flowers concrete, minerals (i.e. N, P, K), total carbohydrates
and total chlorophylls. Moreover, the combined treatments of EM at 30 ml/plant + 50 % dose NPK induced high
significant increments of all the aforementioned parameters in the two seasons. Additionally, the combinations
between EM at 30 ml / plant with 75 or 50 % dose Zeolite improved all the studied parameters as compared to
the control in the two seasons. Also, the combined treatments of EM at 30 ml/plant + 75 % dose NPK or full
dose of NPK have a pronounced effect for improving the yield of concrete in both leaves and flowers which
gave the maximum values and its volatile oil recorded 26 compounds in leaves and 23 compounds in flowers
which were identified by using GC/MS chromatography analysis. The main component was the Butyl-2
ethylhexyl phthalate (17.22 to 37.11%) in the volatile oil of violet leaves and flowers, respectively. |
