TROPICAL YAMS AND THEIR POTENTIAL, PART 3 



37 



progressively narrower role in 

 subsistence agrictulture. On the 

 other hand, the size of the role may 

 increase. Better varieties, now 

 being selected from a worldwide 

 collection, will be distributed 

 throughout the Tropics and will re- 

 place many inferior types now in 

 use. In some areas, these may in- 

 crease the popularity of yams. 



A successful future for D. alata 

 depends on extending the yam sea- 

 son or avoiding waste of the too 

 abundant, too short harvest. The 

 possibility of planting and harvest- 

 ing all year around does not appear 

 good because seasonal response is 

 difficult to change and a broad 

 enough spectrum of varieties is not 

 available for staggered year-long 

 planting. Year-round production 

 in some locations near the Equator 

 with well-distributed rainfall 

 might be possible, but in most 

 cases, yams will mature during the 

 dry season and will be overabun- 

 dant. 



Improved storage of tubers is 

 probably the best solution for ex- 

 tending availability of D. alata in 

 subsistence agriculture. Simple 

 techniques of storage in pits and 

 yam barns are already known, but 

 information about their relative 

 merits is not readily available. It 

 is hardly likely that research will 

 improve techniques for the small 

 farmer, but the economies of com- 

 mon storage techniques do need to 

 be compared and evaluated. 



Extension of yam availability 

 can also come about through wider 

 use of processed products. Of 



these, the most important is flour, 

 but neither the present processing 

 techniques nor the varieties of D. 

 alata now available can be recom- 

 mended. With respect to the vari- 

 eties, the chief problems are ir- 

 regular tuber shape, a difficulty in 

 preparation; excessive polypheno- 

 lic oxidation; and drying. The first 

 two problems can be resolved, per- 

 haps, through the use of better 

 varieties. The problem of drying 

 can be attacked through the use of 

 inexpensive solar dryers. To com- 

 plement the dryer, inexpensive 

 household devices are needed to 

 peel and chip the tuber. These de- 

 vices will have to cope with the 

 large quantities of gums released 

 in the operation. 



Finally, new cooking techniques 

 and recipes are needed for new 

 and stored yams and for yam flour. 

 In particular, bread recipes using 

 yam flour in place of imported or 

 purchased flour should be devel- 

 oped. 



Overall, then, the future of the 

 wing-stemmed yam in subsistence 

 agriculture appears good. The 

 distribution of varieties and 

 knowledge, the development of 

 new techniques for preparing 

 flour, and new recipes will help 

 assure that future. However, the 

 greatest future for D. alata should 

 lie not in subsistence but in modern 

 agriculture, since progress for 

 large numbers of people requires 

 that more food be produced more 

 economically. This has heretofore 

 been accomplished by the use of 

 machinery powered by fossil fuel. 



