Influence of harvesting stage and inorganic and organic fertilizers on yield and oil composition of rosemary (Rosmarinus officinalis L.) in a semi-arid tropical climate

Rosemary (Rosmarinus officinalis L.) is an evergreen woody aromatic herb with a characteristic aroma and lavender like leaves and is suitable for use in perfumes, soaps and fragrances. A field experiment was conducted at Bangalore, India, to study the influence of harvesting stages and inorganic and organic fertilizer on yield and oil composition of rosemary in a semi-arid tropical climate. Results revealed that seed setting stage (HS4) produced maximum plant weight, herbage and oil yield of rosemary compared with other stages of harvesting. Combined application of vermicompost 10 t ha−1 + fertilizer NPK (100:25:25 kg ha−1) significantly increased the herbage and oil yield of rosemary compared control (no fertilizer) (T1) and vermicompost (T2) and on par with treatment T3, T5, T6 and T7. Herbage yield increased by 66.1% and oil yield by 54.9% with the application of vermicompost 10 t ha−1 + fertilizer NPK (100:25:25 kg ha−1) which indicated that 50% inorganic fertilizer can supplemented with organic manure without affects the oil yield of rosemary. Oil content and composition were influenced by harvesting stage but fertilizer levels were not influenced the content and composition.

► Effect of harvesting stages on growth, yields, oil composition of rosemary studied.
► Influence of fertilizers studied on growth, yields, oil composition of rosemary.
► Seed setting stage concluded as to give optimum herbage and oil yield of rosemary.
► Optimum herbage and oil yield is obtained with fertilizer treatment T4.
► Oil composition was not influenced by fertilizer application.