2l8 



CASSAVA TRIALS IN 1905, II. 



By H. H. Cousins, Island Chemist. 



In continuation of the report published in this Bulletin* the 

 results of the Varietal test of the 22 Cassavas at Hope after fifteen 

 months' growth are now presented. Besides the tonnage of tubers 

 per acre, the composition and the indicated starch per acre, a 

 statement is given of the increase (or decrease) in tubers and of 

 starch per acre resulting from the 3 months' growth since the first 

 results were obtained. The results are very encouraging for the 

 Cassava industry and indicate that the gross yield of starch per 

 acre obtainable in Jamaica is far beyond the estimate previously 

 accepted by the writer as a basis for considering the commercial 

 possibilities of the starch industry. 



In these trials the variety that was second in the order of starch 

 yield at 12 months now leads by a large margin and "Long Leaf 

 Blue Bud" heads the list both in tonnage and in starch content. 

 This cassava has given 15^ tons of tubers per acre containing 37^ 

 per cent, of starch equal to 12,857 lbs. starch per acre (6 tons.) 

 The 3 months' extra growth has enabled the plant to make nearly 

 5,000 lbs. more starch per acre. On the other hand "White 

 Top" the variety from St. Elizabeth that led at 12 months, 

 has only added half a ton per acre and a slight loss of starch is 

 indicated as a result of leaving the plant for another 3 months 

 Clearly this is a variety that should be harvested at 12 months 

 and will not give profitable returns for a longer season of 

 growth. 



" Blue Top" has proved itself a good variety and comes second 

 with an indicated starch yield of 9,733 lbs. per acre. 



The Manchester Cassavas "Mass Jack," "New Green," and 

 " Yellow Belly" have proved themselves quite worthless as starch 

 producers at Hope. "Brown Stick" made the greatest gain of any 

 variety in the 3 months (over 8 tons per acre) and it is possible 

 that in the final reaping of the plots at 18 months' growth that 

 this well-known variety will hold a higher position. 



These results indicate that Cassava varieties differ very greatly 

 in their productive power and period of maturation and, consider- 

 ing the extreme variety of our local conditions, it is very desirable 

 to carry out careful trials in all the Cassava districts. 



We can recommend " Long Leaf Blue Bud" and " Blue Top" as 

 two of the most promising varieties tested at Hope. The analyses 

 of these tubers were made by Mr. F. A. Thompson of the Labora- 

 tory staff, while the tonnage was determined by the staff of the 

 Hope Experiment Station. A third report of the results of 18 

 months' growth of the 22 varieties will be presented in due 

 course. 



* Bulletin of the Department of Agriculture, Vol, III,, July, 1905, pp, 152-155. 



