Published on March 11, 2014
Dioscorea alata YAM Araceae South East Asia 2n =28: Dioscorea alata Y A M Araceae South East Asia 2n =28 PowerPoint Presentation: Dioscorea SP COMMONLY KNOWN AS Y A Ms These are under monocotyledons PowerPoint Presentation: Yams are grown as crops of subsistence the constituent the important source of food in tropical Asia and America and Asia. They are rich source of Carbohydrates Importance : The tubers of yam contain minerals, vitamins, proteins, amino acid and they have medicinal properties. The yams are consumed after roasting in the form of chips, flakes or flour. Most of these yam contains sapogenins (base of steroidal drug ) and alkaloids . The main saprogenic is diosgenin . This is widely used in the preparation of carticosteroidal drugs for oral contraceptive pills. The flour of yam is called fufu .. PowerPoint Presentation: pottage: The yams are perennials but cultivated as annual for potting purpose. Some times it is replanted every year. The edible part of yam is tubers of rhizomes. Asiatic YAMs major yams of india Dioscorea alata / greater yam,/water yam, winged yam and larger yam (bulb is a minor storage organ ) no seed dormancy. Dioscorea esculenta is known as chinese yam lesser yam. Extensively cultivated in africa recently to india PowerPoint Presentation: Dioscorea rotundata known as white yam. It is an early maturity yammostly dioeciously. It produce viable seeds. Dioscorea bulbifera: it is known as potato yam. This species bear a climbing stem with larger tubers female flowers occurs especially in pairs.bulbil is the major storage organ( Vegetative part that is actuvally the modification of flower(s).it develops into plant directly without formation of seeds Seen in garlic .onian ,,,,,etc PowerPoint Presentation: Dioscorea trifida. Species for diosgenin:Dioscorea floribunda, Dioscorea deltoidea, Dioscorea maxicana, Dioscorea composite Cultivars: CTCRI, Trivendrum released. From Dioscorea alata: sree shilpa 1 hybrid Srikisthi Sri rupa, Srilatha Dioscorea rotundata: grown in west Africa and some India released variety Srisubra, Sripriya. PowerPoint Presentation: Soil: It requires deep soil. Some species may able to spread in shallow soils also loose well drained friable soil is good for its cultivation always avoidsclayey soil. The tubers may get deformed. pH is 5 to 7. Climate: Dioscorea species are largely tropical also grown in sub-tropical regions TEMP: 15 to 30C and the temperature less than 20 C it cannot grow well longer day length - vine growth, short day - tuber growth . It requires well distributed rainfall 700 to 1000 mm. PowerPoint Presentation: Propagation Tubers , Tubers ,tuber pieces in seed piece. Yam is aslo propageted by vine cutting but tuber prodution by this method by this method is slow by vine cutting Species like Dioscorea floribunda It piece should have a head a middle portion or final portion. Size of tuber piece is influenced the yield the tuber piece should not about 56 g to obtain large sized tubers seed tubers of 112 and 150 is recommended. treated with chemical 2, 4 – D 1 ppm The vine cuttings are found to be good also Dioscorea rotendata . Fertile seeds are used as propagating material in Dioscorea hispida and alsoDioscorea rotundata. PowerPoint Presentation: Cultivation: Land is thoroughly ploughed 5 to 6 times later it harrowed well pulverized and leveled and land is raised In flat beds per raised beds. Mound planting can also be done. Tubers are planted in deeply 10 to 15 cm . PowerPoint Presentation: Planting time is march to may. tubers remain dormant for about 2-2.5months in storage.it can be broken artificially by quick dipping in 4-8 solution of of etheline chlorohydrin followed by dry storage (no seed dormancy in D.alata) In yams the sprouting delayed by soaking the tubers for 10 hrs in 0.1% solution of MH PowerPoint Presentation: In general the size of seed tuber pieces in Dioscorea alata ranged between 200-250 g, Dioscorea esculenta 100 to 150 gm is optimum The seed tubers are treated with solution of benlate, benomyl to prevent rotting . Greater yam spacing is 90 x 90 cm. lesser yam spacing at 75 x 75 cm. Immediately after ploughing mulching with dry grass is recommended from order to moisture loss and to minimize the weed growth.