338 DATE SUGAR INDUSTRY IN BENGAL. 



throughout the season. Trees Nos. 2, 8, 10, 15, 17 and 19 are 

 also obviously constantly low yielders. On the other hand, trees 

 Nos. 5, 7, 9, 11, 16 and 20 give relatively constantly high 

 yields. 



Age of tree. -It is difficult from our figures to trace any direct 

 connection between the age of the tree and the yield or composition 

 of juice. Indeed, several years' work would be necessary in order to 

 decide the question. It is generally stated that trees do not give 

 their full yield until they are about 7 or 8 years old. Thus Robinson 

 writes that if the trees are cut for the first time in their 6th year 

 of growth then the yield of juice per tree is about J the yield of juice 

 of a tree of full maturity. 



In the 7th year of growth the yield is about fths and in the 8th 

 year of growth the full yield is obtained. 



In our experiments tree No. 16 which was only in its first year 

 of cutting gave a fairly high yield. Trees which have been tapped 

 for 36 successive years are still giving a good flow of juice. 



AMOUNT OF INVERSION GOING ON IN THE JUICE DURING 



THE NIGHT. 



The collecting pots are attached to the trees at any time after 

 P.M., according to the nature of the weather. They are collected 

 at any time after 6 next morning but many are not collected till 7 or 

 8 o'clock. So that much of the juice is exposed to the air 12 15 hours. 

 In this time a certain amount of inversion might be expected to 

 go on. To get an idea of how great the loss from this source might 

 be the following experiments were made in February 1911. 



A large quantity of juice was collected in the evening and several 

 pots were about half filled with it and then hung up on trees again, 

 trees of course which were not giving juice. The juice in each pot 

 was analysed over night and again next morning. The results are 

 shewn : 



