EXPLOITATION OF DIOSCOREA DELTOIDEA IN N. W. HIMALAYAN REGION

Summary

Extensive surveys of the north–western Himalayan region have shown that it is fairly rich in D,. deltoidea. Area lying between rivers Ghenab and Beas grows an excellent quality of the material and large quantity of the rhizome can be annually collected from this part of the zone. Optimum climatic requirements are, rainfall varying between 100 to 200 cm. and minimum temperature in winter going below freezing point and in summer maximum temperature not exceeding 32° C. The average size of the rhizome in different localities varies from 13 to 52 gm. and distribution is sporadic to common. Bhadarwah is the richest area with commonly occurring plants, large size of the rhizome and high, upto 8 per cent, diosgenin content. A study of the seasonal variation of diosgenin content has shown that end of autumn is the best season for extraction of the drug.

Collection charges have ranged from Rs. 25 to Rs. 170 per quintal due to depletion of nearby and easily accessible sources. Attempts to cultivate the plant have shown that it may be cultivated in the mountainous regions of temperate Himalayas.

Zusammenfassung

Dioscorea deltoidea kommt im nordwestlichen Himalayagebiet ziemlich häufig vor, so daß dort größere Mengen an Rhizomen gesammelt werden können. Ihre Größe schwankt zwischen 13 und 52 g. Der Diosgenin–Gehalt ist im Spätherbst am höchsten. Reiche Vorkommen finden sich in Bhadawah, wo die Rhizome sich durch ihre Größe und besonders hohen Gehalt – bis zu 8 % – an Diosgenin auszeichnen. Versuchskulturen in gemäßigten Gebirgsregionen des Himalaya verliefen erfolgversprechend.