Agroclimatic zone based metabolic profiling of turmeric (Curcuma Longa L.) for phytochemical yield optimization

• A high yielding superior turmeric genotype was cultivated at nine agroclimatic regions.
• Sensitive factors for curcumin content were altitude, soil pH and temperature.
• Phosphorous and temperature were critical for leaf essential oil.
• Nitrogen, phosphorous and potassium were the key determinants for rhizome essential oil.
• Essential oil yield and quality are controlled by environment and soil nutrients.

Curcuma longa L. belonging to the family Zingiberaceae is an important spice and medicinal plant. Despite an ever growing interest and commercial importance of curcumin and Curcuma essential oil, it is still not clear as to the nature and mode of influence the different soil and environmental factors have on the production and quality of curcumin, leaf and rhizome essential oil of this species. The present report deals with ‘Surama’, a high yielding turmeric cultivar that was cultivated at nine agroclimatic zones with an objective to analyse the effects the different soil and environmental parameters have on product optimization as well the quality of curcumin and essential oil contents. Variation in curcumin (1.5–5%), leaf (0.37–0.8%) and rhizome oil (0.45–0.7%) were recorded across all the zones. Gas chromatography mass spectrometry (GCMS) analysis of leaf and rhizome essential oil for different experimental zones showed wide variation in their quantity and quality. It was found that for curcumin content, most sensitive factors were; the altitude, soil pH, nitrogen and Potassium content. In contrast, the temperature and phosphorous content were found critical for leaf essential oil while, nitrogen, phosphorous and potassium contents were the key quantitative and qualitative determinants for rhizome essential oil. This study provides essential experimental data that could find effective use in yield optimization and managing varying environmental parameters of this important species for high and quality yield of curcumin, rhizome and leaf essential oil. Identification and critical analysis of sensitive/determinant agro-climatic factors are significant for commercial exploitation as well value addition of turmeric products especially with high alpha phellandrene and tumerone content.