Vol. XII. Xo. 303. 



THE AGRICULTURAL NEWS 



389 



SUGAR INDUSTRY. 



SUGAR-CANE EXPERIMENTS IN 



BARBADOS, 1911-13. 



A ccpy has just been received of the Pdinphlet on the 

 results of the experiments conducted with sugar cane by the 

 Local Department of Agriculture. Barbado.', during the 

 season 191113. During the course of this period vc-y 

 unfavour-ible weather wa.s experienced, which resulted in an 

 irregularity amongst the young canes and a reduction in the 

 yield of sugar considerably below the average. 



For the season under review, in the black soil districts, 

 the average yield of White Transparent was 4,1.51 ft>. of 

 iiiu.scovado sugar per acre. Of the selected varietie.s, the 

 seedling cane B.630S came first with a yield of 5,974 ft. of 

 muscovado sugar, giving an increase monetary yield of 

 )ir29-72 per acre. B.ISJOS came next with 5,421 lb. of 

 muscovado sugar, resulting in a monetary gain of .'?20 70 

 per acre over that yielded by White Transparent. Turning 

 to the experiments on the red soils. White Transparent as 

 plant canes gave an average yield of 4,714 lb. of muscovado 

 sugar per acre. Amongst the seedling canes, B.6450 gave 

 a yield of 7,4f)6 B). of muscovado per acre — an increased 

 return compared with White Transparent of 2,752 Bb. equal 

 in value to §44-86 per acre. B 4934 ci'^ie next with an 

 increased value of S22-20, whilst B. 3922 cime third. On 

 the red .soils as plants, first and second ratoons grown during 

 the season under review, White Transparent gave 12,796 lb. 

 of muscovado sugar worth at $1 63 fier 100 lb., •-7208-57 for 

 the three crops. B.3922 gave 18,713 lb. of muscovado sugar 

 — an increase of 5,917 lb. worth for the three crops •'?96-45 

 more than White Tran.sparent. B.6450 came next with an 

 increase worth !ir69-85 more than White Transparent. 



Of the 2,334 seedling canes which were planted in 1911, 

 seventy four from their field characters and the richness and 

 purity of their juice passed the year's standard and will be 

 replanted at the close of 1913. 



M.\NfRI.VL EXPERIMENTS. 



These experiments were directed as in former years to 

 ascertain the effect upon the industrial yield of the sugar- 

 cane, the application of farmyard manure in ordinary 

 quantity, and in double the ordinary quantity, and in 

 varying quantities of nitrogen, phosphoric acid and 

 potash contained in the usual commercial fertilizers. 

 As already mentioned, the weather conditions were very 

 unfavourable for the development of sugar-cane, and the 

 Iresults obtained in the manurial plots clearly indicate that 

 the want of rain has been the limiting factor in the regulation 

 of the results. The best monetary result in the nitrogen 

 series was obtained where 60 lb. of nitrogen as dried blood 

 was applied, all in January. A net gain of •S7o4 was obtained. 

 The next highest yield was obtained where only phosphates 

 and potash were applied. This was followed by the plot to 

 which 40 lb. of nitrogen as dried blood was applied, 1.5 Bb. 

 in January and 25 lb. in June. The application of sulphate 

 of ammonia had a distinctly depressing eflect. 



In considering these results financially with those for the 

 last twenty years, it is interesting to note that in the nitrogen 

 series for the longer period, the best monetary result.^ were 

 obtained where 40 lb. of nitrogen as sulphate of ammonia 

 ■was applied, 15 lb. in January and 251b. in June. The next 

 best result was obtained from the divided application of dried 

 blood. As regards the phosphate series, there has always 



been a lower yield in all the plots to which phosphate has 

 been applied than in the no-phosphate plot with the excep- 

 tion of the plot to which 100 tt). of basic slag has been 

 applied per acre. In the potash series, in all the plots, with 

 the exception of the one to which 60 It), of pota.sh as sulphate 

 of potash was applied, all in January, there was an increase 

 varying in the case of the no-manure plot from §2 75 to 

 •^9 94, and in the case of the no-potash plot from 56c. to 

 •'5'513 per annum. 



As the superphosphate of lime plots have given a loss 

 on the average for the twenty years during which the 

 experiments have been carried out, and also as the 

 dried blood plots have apparently given better resulta 

 during the last few years than they did at first, it 

 was deemed desirable to compare the average returtt 

 of the first ten years with those of the second ten years, 

 with a few to ascertaining whether the nophoiphate 

 plots give now any indication of requiring phosphates. 

 It would appear that this is not the case, since for the first 

 ten years the yield on the no-phosphate plot was, on the 

 average, 7,820 lb. of sucrose per acre, whilst in the 

 second ten years the yield was 8,233 Bb. — a diflference ia 

 favour of the second period of 413 tt). of sucrose per acre. 

 That this increase cannot be due to rainfall conditions is shown 

 by the fact that the average precipiBation per annum for the 

 first ten years was 6958 inches compared with that of the 

 second ten years, which was 56-32 inches. The increased yield 

 has therefore been due, most probably, to the regularity in the 

 application of farmyard manure, and to thorough tillage. That 

 this is likely is seen from the fact that the no-manure plots 

 gave during the second ten years 4'73 ttj. of sucrose per acre- 

 more than was yielded during the first ten years. It should 

 be understood that these experiments were conducted on 

 identical plots. 



Further information is given in this report in regard to 

 special experiments with sulphate of ammonia, nitrate of soda, 

 nitrate of lime and calcium cyanamide. Want of space prevents 

 reference to these, and to the large amount of other interesting' 

 information but barely touched upon in this review. In con- 

 cluding, however, it may prove generally interesting to refer 

 briefly to the facts recorded in the report in regard to the range 

 of probable error in the experiments. The yields of four 

 similar control plots were compared. The difierence between 

 the yield of the plot which was highest and that which was 

 lowest amounted this year to 1,624 D>. of sucrose per acre — 

 a difference of 31 per cent. Further, a difference between the 

 highest yield and the average of the four plots was + 15-39 

 per cent, and between the average yield of the four plots and 

 the lowest - 11-69 per cent. Reference to most of the tables 

 of varieties for 1913 will show that this difference of 1,624 lb. 

 corresponds to the difference in the yield given by the lowest 

 variety and that occupying perhaps the tenth position in a 

 list of fourteen canes. It would appear, therefore, that for 

 the first year most of the results in each table of selected 

 varieties, fall within the range of experimental error. 



Too much importance must not, therefore, be attached 

 to the individual monetary gains, and it would seem safer 

 to regard the list of seedlings in each table rather as a group 

 of promising varieties, and not to compare too closely 

 the plants individually, at least from the grower's point 

 of view. 



At the end of the report the extension of the area 

 under B.6450 is commented upon, and it is stated that the 

 average increased value to the island in the near future 

 from the cultivation of this cane should not be less than 

 £100,000 per annum. 



