Effect of Irrigation Intervals and Foliar Spray of Micronutrients on Growth, Yield and Essential Oil Production of Rosmarinus officinalis l. Plant.

Abstract

The present study was carried out at Mansoura Horticulture Research Station, Dakahlia Governorate, Hort. Res. Institute, Agric. Res. Center, Ministry of Agric., during the two successive seasons (2011/2012) and (2012/2013) to study the effects of irrigation intervals and micronutrients on growth, herb yield, leaves yield, essential oil production and its components of rosemary (Rosmarinus officinalis L.) plant. The results showed that: irrigation interval every 7 days resulted in significant increase in vegetative growth characters as well as essential oil content per plant, but irrigation interval every 21 days increased essential oil percentage in the two cuts during the both seasons. Foliar spray with micro elements Fe, Zn, Mn individually and mixture between them recorded significant increase in vegetative growth, as well as the highest essential oil content per plant in the first and second cuts of the two seasons compared to the control. In addition, the previous values of characters were increased by using (Mn) to reach their maximum values by using the mixture of (Fe+Zn+Mn) at 150 ppm in both cuts of the two seasons. The interaction between irrigation interval every 7 days with foliar spray of a mixture, followed by Mn at 150 ppm gave significant increase in vegetative growth, as well as the highest essential oil content per plant in the first and second cut of the two seasons. In addition, the irrigation intervals every 21 days with same spraying treatments gave the highest essential oil percentage compared to other ones or the control plants. The irrigation interval every 21days gave the highest main components of essential oil (camphor, 1.8-cineole and α-pinene) which recorded (50.04 %), while the interaction between irrigation interval every 21days with foliar spray (Mn) at 150 ppm gave the highest main components (65.53 %) followed the mixture of the microelements (60.85 %) of the rosemary essential oil.