THE HUSBANDRY OF THE CANE 137 



to take off plant cane and first ratoons. In Mauritius the fields are allowed 

 to grow up to third ratoons as a general rule. In Cuba, the West Indies 

 and in British Guiana fifth ratoons are not uncommon, and fields that have 

 not been replanted for a generation may be found. Much of this land has, 

 however, been supplied \\ith tops from time to time, so that little of the 

 original stock may remain. In Hawaii canes are seldom allowed to grow 

 beyond third ratoons. Generally speaking, it is only those familiar \\'ith 

 local conditions who can determine the profitable period of ratoonage. 



Long-continued ratoonage has been connected with the prevalence of 

 various diseases, particularly those affecting the root and root stock, as in 

 in this case the causal funerus has a continuous habitat. 



Yield of Sugar per Acre. — The return of cane and of sugar per acre is 

 determined by the soil, the climate, including herein temperature, rainfall 

 and its distribution, the use or not of irrigation and of manures, the efficiency 

 of the cultivation, and the degree of ratoonage practised. The highest 

 yields are those which are obtained on the irrigated plantations of the 

 Hawaiian Islands, where the canes are often allowed a period of growth of 

 twenty months. Yields nearly equal in magnitude are obtained on the 

 irrigated lands of Peru, but probably the greatest return per acre per year 

 is to be found on the plantations of Java where the crop is almost entirely 

 plant cane. Outside of these favoured areas the j'ields are much smaller 

 and probably do not average much over twenty short tons of cane, or two 

 short tons of sugar per acre. The maximum fields that have ever been 

 reported are in the Hawaiian Islands, where crop averages on large planta- 

 tions of more than 20,000 lbs. of sugar per acre have been recorded, and where 

 a single field of over 300 acres has been known to peld at the rate of just 

 over 100 short tons of cane and 15 short tons of sugar per acre. 



Some actual records, all in short tons per acre, are given below. 

 Jara}^ — For the years stated the returns have been : — - 



Later results have shown a distinct increase, the return of sugar for the 

 years 1906, 1907, 1909, 1911, 1912, being 4-49, 4-55, 4-77, 4-49 and 4-47 

 tons respectively, corresponding to a \'ield of from 40 to 45 tons of cane per 

 acre. This regiilar and progressive increase is to be attributed to the appli- 

 cation of the results of technical research. 



HawaiiP — For the period 1895-1910 the return of sugar per acre has 

 been as below expressed in short tons per acre. On the irrigated plantations 

 a distinct rise in production (equally, as in Java, to be attributed to the 

 teachings of applied science) is seen, and this is actually more than the figtu-es 

 indicate, since it was onl}' the more favoured areas which were planted 

 in the earlier years. The rainfall plantations show the effect of climate. 

 The \deld from cane is, when averaged over a long period, a little under 

 14 per cent, from irrigated and a little over 11 per cent, from rainfall cane. 



