126 



THE AGRICULTTJRAL NEWS, 



APKEt 19, 1919. 



CASSAVA EXPERIMENTS IN TRINIDAD. 

 {Conclutkd.) 



Thi> following is the eoiiclnsior of the account of 

 expiTiiii^-ntsin the t-iiltivittion ofc.-issava at the Geveni- 

 jnejit Fai"u», »St. Aii^'ustine, Trinidail, which appeared 

 in thf Bulletin of the Dfpartvient of Agriculture, 

 T-rmidud and Tobago, Vt'l. XYII, part 4, 1918, the 

 fii-st part wf which whs reproduced in the previous issue 

 ©f this Journal : — 



From 1916 experiments bave been carried out with the 

 object c,f ascertaining the best time for planting cassava. 

 Accordingly, from the end of April and thence monthly 

 t(i March of the following year, duplicate plots were 

 planted of the same variety. These plots were reaped, and 

 the percentage of starch determined, between September and 

 October, when the plants were from six to seventeen months 

 ol age according to the date planted. 



The results obtained for l'.tl7-18 experiments are similar 

 to. and in every respect confirm, those obtained the previous 

 yf-ar. 



In this expeiinifnt twelve duplicate plots were planted 

 about the middle of April. Two plots were reaped in the 

 middle of October and thence monthly to September of the 

 following year, so that the cassava was from six to .seventeen 

 months old. The percentage of starch was alio estimated in 

 samples from these plots about twenty-four hours after they 

 ■were reaped. 



The results obtained for the 1917-18 experiments also 

 are similar to and confirm the results of the previous year. 



The results recorded show that: ( 1 ) the yield of the 

 roots ha-i increased generally from mouth to month with the 

 age of the plants: (2) that the percentage of .starch does not 

 necessarily increase with the ige of the plants, but that it is 

 subject to great fluctuations according to the weather expe- 

 rienced at time of reaping. 



From all the plots reaped in July, August, and September, 

 it was observed that a large proportion of the tubers had 

 rotted, and this may account for the fact that no increase 

 in yield was obtained from these plots as compared with the 

 plot reaped in June. From this it is evident that cassava 

 should be reaped before .July, and it should then be not less 

 than sixteen to seventeen montb.s old, as a better yield may 

 be expected at that age than at fourteen to fifteen months 

 of age- 



An impiiriant con.sideration in the growing of cassava is 

 not only to obtain the largest tormage of roots per acre, but 

 also the highest percentage of starch in the reots at the time 

 of reaping. So far as has been ascertained, there is little or 

 no difference in the percentage of starch from the different 

 varieties. 



The age of the plants also appears to exert very little 

 influence on the percentage of starch in the roots, at least 

 for cafsava over eight months of age. For example, cassava 

 ten and eleven months old, reaped in the dry season, con- 

 tained a larger percentage of starch than cassava fifteen, 

 sixteen, and seventeen months of age, reaped during the wet 

 season. All the deterniination.s made, over a period of two 

 years, show that cassava reaped between July and December, 

 seldom contains more than 22 per cent, of .starch, but that 

 the amount u.sually found varies from 1-5 to 18 per cent. 

 Reaped between January and June, cassava r)f the same age 

 seldom contains les.^ than 22 per cent, of starch, and often 

 ■saches over 27 \>eT cent, in Match t<> April. The dry season 

 therefore is undoubtedly the proper season for reaping the 

 cassava and as it has been found that the yield increases up 

 to seventeen months of age, it is probable that the planting 



season would be from Peptember to November, so that the 

 roots may be reaped between February and April at seventeen 

 and eighteen months of age. 



Preliminary small seal- raanurinl experiments made oi> 

 plots of approximately one-fourhundredths of an acre show that 

 a yield of frori 10 to 13 tons of roots per acre may be obtained 

 from an appHcation of 20 tons pen manure or 300 ft. artificial 

 manures per acre. The pen manure plot gave a yield of 

 1345 tons, and the two artificial manure plots 10-32 and 

 1 1 '60 tons of roots per acre- The artificial manure applied 

 consisted of a mixture of 30 B). sulphate of ammonia, 180 lb. 

 dissolved bones, 55 lb. fine bone-meal, and 4-5 lb. sulphate of 

 potash. An extra amount of sulphate of potash, at the rate 

 of 100 B). per acre, was applied to the plot which gave 11-60 

 tons of roots per acre. These experiments were made with 

 variety 'Sellier', and the control plots only gave 4-85 tons 

 per acre. The yield from the control plots is low for this 

 variety, and is accounted for by the fact that they were 

 overshaded by the fast growth of the manured plots. The 

 average yield for variety 'Sellier' for the past two years has 

 been from 7 to 8 tons of roots per acre 



Owing to the difficulty of obtaining high yielding 

 varieties, and the low yield obtained from most of the local 

 varieties, attempts have been made at growing new varieties 

 from seed. Cassava does not seed very profusely, and .some 

 difficulty has been experienced in collecting good seed, as 

 only a small proportion of the seed appears to come to 

 maturity. 



Out of thirty seedHngs raised in 1916, six have given, 

 sufficiently promising yields to be propagated by c.ttings. 



DOWN THE ISLANDS. 



ITEMS OP LOCAL INTEREST. 



ST. LUCIA. During the month of March plant distribu- 

 tion included 144 GUricidia cuttings and 13 packets of veget- 

 able seeds. Mr. Brooks states that the lime crop is over, and 

 reaping operations were still in progress in connexion with the 

 sugar crop. During the month a leaflet on liice Cultivation 

 was issued. The total rainfall recorded at the Botanic 

 Gardens, Castries, was 2 87 inches; the record at the Agricul- 

 tura and Botanic Station, Choiseul, was 49 parts. 



ncMiNiCA. From notes forwarded by 'Mr. Joseph Jones, 

 Agricultural Superintendent and Curator, it appears that 

 during the month of March 20 barrels of fruit were reaped 

 from the lime experiment station, making a total for the 

 year of 1,080 barrels. Plant distribution included: onion 

 seedlings, 5,000; cane cutting.s, 3,000; vegetable seeds sold, 

 330 packets. There w»s con.siderable activity in the fresh 

 lime trade, the local price of which advanced from 16.f. to 

 25.V. per barrel during the month Kipe limes remained 

 unchanged at 5s. per barrel. Green limes are scarce. Cured 

 cacao is in demand at 17c. per lb. locally. Three bags of 

 camphor leaves were sent to the Government Laboratory, 

 Antigua, for trial, distillation. The rainfall for the month, 

 recorded at the Botanic Gardens, was 69 parts. This, 

 Mr. .Jones states, is the lowest fall on record for March since 

 the Gardens were started. The rainfall during the quarter 

 totalled 4-63 inches- The drought is becoming severe along, 

 the south leeward coast; there is sufficient rain, however,. 

 in other districts of the island. 



