Vol. VIII. No. 199. 



THE AGRICULTURAL NEWS, 



SUGAR INDUSTRY. 



387 



THE SUCROSE CONTENT OF STORM- 

 BROKEN CANE. 



In the last number but one of the A(jrlcultaral 

 N'eivs, (No. 197), reference was made to the behaviour 

 of the cane D. 74 in the storm which passed over 

 Louisiana in September. Further information with 

 regard to the effect of breal^age on the sucrose 

 content of the growing cane is given in a report which 

 was made on the subject by the Assistant Director of 

 the Louisiana Sugar Experiment Station. This report 

 appears in a recent number of the Sugar Planters 

 Journal, and from it the following abstracts are 

 taken : — • 



At the time of the severe storm of September 20, 

 there were wild nimonr.s of great disaster tc the cane-crop! 

 It is now realized that the damage done was far less than was at 

 first thought. In a report from the Sugar Experiment Sta- 

 tion on October 2, based upon actual counts of broken cane 

 in several sections of the sugar belt, it was estimated that 

 the damage to the cane-crop as a whole was slightly less than 

 3 per cent. Practically ail of this 3 per cent, damage 

 occurred in those field? which were planted in the D.7-t 

 cane. There were presented, in the same report, data fron; 

 actual plantation conditions, which showed this seedling to he 

 a vastly superior variety to the Louisiana Purple. Calcula- 

 tions indic-iiied that, even in spite of the hurricane, fields that 

 were this year in I). 7-1 would give better yields of sugar to 

 the acre than those planted in the home varieties. In 

 making these calculation.s, where data were available, only 

 thoroughly reliable figures were used. It was necessary, 

 however, to base certain parts of the report on estimates, and 

 in doing thi.s, an effort was made to be as conservative as 

 possible. For instance, the question arose as to what would 

 he the ultimate sucrose content of those stalks which had 

 been broken oft' by the wind. Some predicted that there 

 would be a significant deterioration in the sugar content 

 held by these canes at the time they were snapped. No 

 figures from past experiences were obtainable on this point; 

 nevertheless, it was thought safe to assume that whereas 

 there might be no increase in .sugar, there would be no 

 appreciable diminution of that which was already held. 

 Consequently, these broken stalks were estimated as havinf 

 SO per cent, of the value of unbroken ones. 



Now, however, it is possible to give data on what has 

 taken place, as regards sugar content, in the canes that were 

 broken. Immediately after the storm, it was decided to 

 conduct a .series of laboratory tests which woidd indicate, 

 from week to week, the increase or decrease of sucrose in 



juice of the damaged stalks. The results were as follows ; 



Date. Sept. 22. Sept. 25. Oct. G. Oct. 13. Oct. 20. Oct. 26. 



Date. Sept. 22. Sept. 25. Oct. 6. Oct. 13. Oct. 20. Oct. 26. 



BROKEN RATOON CANES 



Bri.x 13-35 1289 13-66 1393 14-03 1330 



Glucose 2-53 2-55 2-19 1-98 208 1-90 



Sucrose 9-26 9-24 10-06 10-79 10-53 9-9 



Purity 67-1 71-8 73-6 77-4 75-0 74-4 



SOUND RATOON CANES. 



Bii.x 12-35 14-04 14-04 14-50 15-63 1380 

 Glucose 2-89 2-55 2-22 2-19 1-86 -'08 



Sucrose 8-31 10-59 10-37 11-33 11-73 lOSO 

 Purity 67-.3 761 73-9 78-1 75-0 782 



The cnly practical way of getting these data was to obtain 

 them troni small samples of cane taken from the field at inter- 

 vals. The juice from five representative stalks furnished the 

 material for each sample. Every chemi.st realizes the variation 

 in sucrose content of individual stalks, and is aware that 

 a small number of stalks only appro.ximately represents the 

 conditions of a field. But even with this to detract from the 

 value of the results, the figures presented give a fair guide to 

 wliat has taken place. In inspecting the sucrose column 

 under broken canes in the table, it is seen that there was 

 a steady increase up to October 13, twenty-one d^^ys after 

 the storm, but that after this there was a decline There 

 has also been a sliglit decline in the purity coefficient. It is 

 a significant fact that this decrease in purity has not been pro- 

 portional to the falling oft' in sucrose; and that the glucose has 

 also dropped oft'. This indicates that there has been no 

 great deterioration in the juice of the broken cane. 



The increase in .sugar with the subsequent decrease may 

 be thus explained. Shortly after the stalks had been broken 

 there was a period of cool weather which checked the germina- 

 tion of the eye.s, and promoted the ripening of the cane 

 ^\ith the warm weather which followed, these eyes sent out 

 shoots ^^•hlch derived their food-supply from the juice of the 

 stalk. Both sucrose and glucose have lessened in about 

 proportional (piantities. There has been but little increase in 

 solids not sugars. The decrease in degrees Brix may be 

 partially attributed to the dilution of the juice from heavy 

 rains, and partially to a certain amount of solid matter 

 having been utilized by the sprouting eyes. 



The data obtainefl on ratoon cane substantiate in 

 a general way the results obtained on j.lant cane, and .serve to 

 bear out the deductions made. 



There are one or two discrepancies which occur in the 

 data on ratoons. For instance, from October 20 to 

 October 26, there is a decline in sucrose in the undamaged 

 canes and at the .same time a decline in total solids (Bri.x) 

 This may be attributable to the rainfall' of a little over 2 

 inches about the twentieth of the month. This would have 

 likewise affected the plant cane, and the fact that a similar 

 decrease is not noted in the plant canes is possibly due to this 

 cane having ripened sufticiently to oftset the dilution of 

 juice by water taken from the soil. 



No importance should be attached to the slight increase 



in Brix and glucose on broken ratoons between October 13 



.and October 20 which occurs simultaneously with 



a decrea,se in suci-o.se, as this discrepancy is certainly within 



the limits of the accuracy of sampling. 



To summarize, there has been a decrea.se in sucrose in 

 the broken canes since October 13, up to which time there 

 was an increase. Up to October 26, thirty-four days after the 

 storm, this deterioration liad not oftset the accumulation of 

 .sucro.se which had taken place up to October 13. 



Not only should the data prove of practical benefit, but 

 they_ should present an interesting study for the plant 

 physiologist to ascertain just what chemieardianges occur m 

 these crippled canes in their efforts to survive. 



