The effect of drought stress, chimical fertilizer and biofertilizer on yield and essence content of borage (Borago officinalis L.)

Medicinal plants are of great importance in providing community health. In order to investigate effect of drought stress and bio fertilizer on yield and essential oil content of borage a split plot experiment based on randomized complete block design with three replications was done at the Agricultural Research Station of Islamic Azad University of Roudehen in 2014. Treatments were the main plot was drought in four levels (control, stress at vegetative stage, stress at flowering stage, and stress at vegetative+ flowering stage) and the sub plot consisted of three levels of fertilizer treatments (100% chemical fertilizer, 50% chemical fertilizer+ bio fertilizer, 25% chemical fertilizer+ bio fertilizer). Results showed a significant effect of drought stress on mucilage percentage and flower yield but the effect of drought stress on essence yield was not significant. The highest mucilage percentage in the stress at Vegetative +flowering stage treatment with an average of 6.35% was obtained. The highest and least flower yield in the control and stress at Vegetative +flowering stage treatments, (with an average of 450 and 364 kg.ha-1) was obtained. Effect of fertilizer treatments on essence yield and flower yield was significant and the percentage of mucilage was not significant. Interactions between drought stress and fertilizer treatments on essence yield, flower yield was significant and 50% chemical fertilizer+ bio fertilizer was best treatment.