Vol. VIII. No. 181. 



THE AGRICULTURAL NEWS. 



9'.) 



SUGAR INDUSTRY. 



Manurial Experiments with Sugar-cane 

 in the Leeward Islands, 1907-8. 



Th .iiiini;il experiments conducted with siicjtir- 



•cane in t.lii' Lceu.uil Irihunis have already deinoiistmted, 

 so far a.s pl.-int canes ;iic concerned, that artificial 

 mamires aie not reniimeiMti ve. provided that adequate 

 supplies of pen manure <>r UKUiures of a similar nature 

 are obtainable. Manurial expeiiments with plant canes 

 have, therefore, been di.scontinued, and such trials 

 Hre now conducted only with ratoon canes. Pamph- 

 let No. .57, in the seiie.s issued by the Imperial 

 Department of Agricultuie, entitled ' Manurial Experi- 

 ments with Sugar-cane in ihe Leeward Islands, IflOT-S," 

 has just been published, and gives in a brief form 

 the results of the experiments conducted with the crop 

 vhich was reaped last ye;'r. This work consists of the 

 thirteen-fold repetition of the thiit.y-three experiments 

 adopted since 11)00 fir use at the Experiment Stations 

 in Antigua and .Sr. Kitt's. The iti\est;igations relate to 

 ratoon canes only, the plant canes which preceded the 

 ratoons not having received any artificial manuies, 

 since the object of the experiments w.is to ascertain 

 what artificial manures, if any, will prove remuiier.-itive 

 with ratoon canes under the conditions obtaining in 

 ordinary agricultuial practice in the two ishimis in 

 <|uestion. The work w.-is conducted at four stations in 

 'Antigua and three in St. Kiti's, and in every instance, 

 except one, the experiments were carried on in dupli- 

 cate. There were thus about 400 exfieriinent plots. 



The results obtained on each of tlie.se 400 ]ilots will 

 «liuitly be publi.shed in the full report on these experiments 

 that is about to be i.s.sued. The present pamphlet .simply 

 cleals with the average re.sults obtained on the plots as 

 ji whole. 



The expeiiments comprise control plots receiving no 

 manure, plots receiving pen manure, and plots receiving 

 nitrogen, potash, and phosphates in various combinations. 

 The results are given in the form of both tables and diagrams, 

 And show the weight of cane obtained in each of the thirty- 

 three plots, the increment due to the use of manure, the cost of 

 the manure, the value of the increment, and the consequent 

 jtrofit or loss. It is to be noted that in every instance during 

 the season 1907-8 the use of manure has increased the yield 

 oi cane, but not always to a profitable ixteiit. As the i>rofit 

 <lepends upon the value of the cane, the profit or loss is 

 calculated on two assumed values for canes, viz., 10s. 10'/. 

 per ton, a value formerly adopted for the purpose of compari- 

 «on in these experiments ; and I5s. [Oil. per ton, a value 

 approximating to that paid by the Antigua sugar factory 

 for canes during the reaping season 1908. 



For the details of the experiments tlie reader is referred 

 to the pamphlet, but it may be -here stated that, on the whole, 

 nitrogenous manures in a <|uick-acting form, such as sulphate 

 of ammonia or nitrate of soda, are necessary for the growth 

 of ratofin canes, but that .several factors control the question 

 -of profit. These factors are rainfall, cultivation, and disease ; 

 and upon these the successful use of manure is dependent. 



At .St. Kilt's the soil is friable and ea.sily ke;it in order, 

 while root disease is not prevalent. The growth is tlieicfoie 

 largely determined by the rainfall, and may be also largely 

 infiuenced by manuring. it .\ntigua in many jilaces tlie 

 soil is stiff, and rei|iiires much efl'ort to keep it in good tilth, 

 w-hile loot disease is widespread. These factors, as well as 

 an irregular lainfall, exert a jaofound infiuence on the yield 

 of canes, and may entirely mask the ett'ect of manure. 



The ex|ieriments support the view, which is in accord 

 with the experience of planters, that under average condi- 

 tions of soil and rainfall, it is desirable, in order to ensure 

 profitable returns, to manure ratoon canes with either 

 sulphate of ammonia or nitrate of soda. When circumstances 

 are such as are likely to result in moderate growth of the 

 canes, it will be sufficient to use about 2 cwt. of sulphate of 

 ammonia or 2i cwt. of nitrate of soda : but when there is 

 a pro.spect of considerable growth, the quantity may be 

 increased to 3 cwt. in the case of sulphate of ammonia, or 

 ■ij cwt. of nitrate of .soda. 



The growth of the ratoon canes is largely dependent on 

 the thorough preparation of the soil and its manuring with 

 pen manure wlieii the [ilant canes are being planied. 



After discussing the results derived from the experi- 

 ments, brief reference is made to the growth of the canes at 

 the seven individual statioiu', and it is seen that these seven 

 •stations i>resent marked ditl'erences, and eorres[ionding 

 differences are "observable in the effect of the manures. In 

 onlei' tn study these, reference must be made to the full 

 reiioit alluded to above, the i.ssue of which may be expected 

 shortly. 



The experiments rejiorted upon dui'ing the year under 

 review amply support the view that nitrogenous manuies 

 are botli remunerative and necessary. It is desiraJ>ie to 

 emi>hasize this, because pi-evious results obtained in this 

 series for thiee years atfnrtled information which threw 

 considerable doubt on the vuhie of manures for ratoon canes. 



"When rei>orting cm tlie results of these three yeais it 

 was observed that the yields were seriously infiuenced by 

 drought, and this circumstance, thete is no doubt, gave ri.se 

 to the iipparent want of value exhibited by the manures 

 under trial. It is satisfactory to observe, that the experimen- 

 tal work now reported U[i<iu shows clearly that, in average 

 seasons, manuies are of considerable use and value. All these 

 ex[ieriinents are therefore closelj' in accord with the practical 

 experience of the planters, who are well aware tiiat in bad 

 .seasons manures produce but little infiuence on ratoon canes, 

 while in good seasons the}' are eminently beneficial. 



In addition to the report on the influence of 

 manures, the writers raise some pertinent questions 

 relating to the effect of the operations of tillage 

 commonlv given to ratoon canes; these will be referred 

 to in the next issue. 



From statistics lately published in the Officii)/ Gim'tti' 

 of British (luiana, it is seen that the area* under rice 

 cultivation, and the average returns per acre in the three 

 counties are as follows : — Berbice : area under rice, 16,097 

 acres ; average return, 2.3' 1 bags per acre; Demerara : area 

 under rice, 13,202 acres ; average return, 21-2 bags per acre ; 

 Essecjuibo : area under rice, 8,552 acres ; average return, 

 3(j3 bags per acre. The higher average return obtained in 

 Essequibo is due to the fact that two crops of rice were 

 grown during the year over an area of about 4,000 acres in 

 that county. 



