Variation in physical standards of milk yam (Ipomoea digitata L.) tubers during its growth and development

Abstract

Milk yam is an underutilsed medicinal plant with proven functional potential with a wide range of therapeutic benefits and its folkloric use as nutraceutical. This study was aimed on evaluation of physical standards of milk yam tubers during its different growth stages so as to assess its optimum stage of harvest maturity for better drug quality. Milk yam vine cuttings having two nodes were raised in polybags and depotted carefully after tuber formation at tri-monthly intervals for a period of two years and subjected to quantitative phytochemical analysis. Tubers harvested at twenty one months after planting recorded optimum physical standards viz., minimum moisture content (57.80 per cent), optimally less crude fiber (6.19 per cent), high ash values (total ash -4.47 per cent, water soluble ash – 3.22 per cent and acid insoluble ash – 0.60 per cent), starch content – 39.17 per cent and pH value, 5.29. Twenty one months after planting is identified as optimum maturity stage for harvesting the tubers with better quality.