Edible Products. 



220 



[September, 191 1. 



The cure, or rather the part of it we 

 can get the data to plot, is quite 

 irregular. 



Tuba. 



Partly for the sake of investigation, 

 partly to give practice, and in chief part 

 because it is hoped that by using some 

 of the trees for tuba, it will be possible 

 to protect the entire grove against the 

 attacks of beetles, a considerable number 

 of trees have been operated on to 

 produce tuba. It might be explained 

 that this is the native name of the fresh 

 or undistilled sap more widely known as 

 toddy. As Mr. Gibbs, of the Bureau of 

 Science, has in press a thorough study of 

 this and other Philippine palm saps, I 

 will here touch on only one point, and 

 on this, the relative flow by day and by 

 night, only because it seems to be in 

 some dispute. 



Table VI shows the flow from two 

 spathes as reported by Cevallos. 

 Prior to February 10 the removal 

 of slices from the bleeding tips was 

 performed three times daily, morning, 

 noon, and night ; from this date on 

 it was performed only morning and 

 evening. The extra slicing at noon 

 would have a tendency to cause a more 

 rapid flow during the day. 



Table VII. 

 Tuba Production, Day and Night. 

 Night hours, bold-Jaced type. 



Spathe. 



1 



2 



' 5 



123-0 cc. 



56*0 cc. 



169-5 



1010 



6 



175-0 



124 





205 



132 



7 ... 



235 



112 





242 



171 



8 



225 



135 





235 



206 



9 



210 



185 





213 



174 



10 , v 



240 



150 





250 



240 



11 



167 



160 





290 



260 



12 



175 



125 





304 



209 



13 



115 



185 





88 



210 



14 



130 



125 





191 



162 



15 



117 



117 



212 



124 



This production of tuba is less than 

 would be obtained by any expert tuba 

 gatherer, chiefly, I believe, because of 

 the excessively thick slices removed by 

 the students ; but I cannot believe that 

 there was anything in their manipul- 

 ation which could cause any abnormal 



distribution through the day of the 

 sap. Further, a greater flow during the 

 night is to be expected a priori as a 

 direct result of exactly the same factors 

 which cause more rapid growth during 

 the night, 



Conclusions. 



The most rapid observed growth of 

 roots is at a rate of about 12 meters 

 around each young tree, kept in good 

 condition and devoted to the use of the 

 coconut, have its radius extended at the 

 rate of one meter a year, the tree will 

 have as much ground as it can use. Only 

 a few roots can grow farther. 



The most rapid observed growth of 

 the leaf is slightly over seven centi- 

 meters a day. This is likely to be ex- 

 ceeded by trees better situated, but is a 

 fair standard of excellence. By making 

 an allowance for the weather, if it is 

 unfavourable, it is possible to estimate 

 the state of thrift of a grove from a 

 day's measurement of growth of several 

 trees. 



The growth is checked by wind, by 

 prolonged rain, and by drought severe 

 enough to lessen the water the roots 

 can absorb. 



The growth of uncultivated trees is 

 checked by surface cultivation ; but this 

 check is temporary, and is followed 

 by a more enduring acceleration. 



Within six months after the appli- 

 cation of fertilizers, the effect can ba 

 seen in accelerated growth of the leaves. 

 This is a practically sure promise of 

 future increase of crop. 



There are leaf-primordia large enough 

 to be recognized with the naked eye, 

 which will still require one and a half 

 years in which to grow to the light ; 

 another year and a half must pass before 

 fruit matures in their axils. Theiefore 

 anything which can influence the rate 

 of development of these youngest leaves 

 will affect the crop three years later. 



The growth of the leaves and the 

 production of tuba are more rapid 

 during the night than during the day. 



I am under obligation to S. Asuncion, 

 F. Cevallos, A. Lejano, A. Navarro, M. 

 Raymundo, and T. Vibar for careful 

 execution of the field work forming the 

 basis of this report. 



