Effect of organic and inorganic sources of nutrients on physiological, biochemical and productivity parameters of ashwagandha [Withania somnifera (L.) Dunal]

A field experiment was conducted during winter seasons of 2010-11 and 2011-12 to study the effect of organic and inorganic sources of nutrients on physiological and biochemical parameters of ashwagandha var. Jawahar-20. Among the organic sources of nutrients, triple biofertilizers (Azospirillum, Azotobacter and phosphate solubilizing bacteria) brought about significantly higher chlorophyll contents (‘a’ and ‘b’), carotene content, phytosynthetic and respiration rates as well as total alkaloid content over the remaining organic sources. However, FYM @ 5 t/ha produced maximum root yield (12.49 q/ha), thereby alkaloid yield (14.7 q/ha). Amongst the inorganic sources of nutrients, 100% RDF (N20P40K20) recorded significantly higher of all these physiological and biochemical parameters including root yield (14.02 q/ha) and alkaloid yield (17.41 q/ha) of ashwagandha.