26 



PHILIPPINE BAMBOOS 



Table 7. — Number of shoots produced and yield of mature living canes 

 from 5 clumps of Gigantochloa levis at Division of Investigation, 

 Bureau of Forestry, Los Banos, Laguna, Philippine Islands. Data 

 from report by Ranger Oro. 



Total 

 number 



of 

 mature 



canes. 



New shoots. 



Per- 

 centage 

 living. 



Per- 

 centage 1 

 yield. 



Total 

 number 



of 

 shoots. 



Total 



number 



of 



dead. 



Total 

 number 



of 

 living. 



22 



36 



25 



11 



31 



50 



16 



39 



27 



12 



31 



75 



12 



26 



19 



7 



27 



58.5 



10 



14 



10 



4 



28 



40 



60 



72 i 45 



27 



37.5 



45 



Average 



31 



54 



The death of the young shoots is due to various causes; some 

 of them are attacked by insects or rats ; others are broken by the 

 wind; while still others die without any very apparent reason, 

 but probably because under the existing conditions more shoots 

 are produced than can be matured by the clump. This may 

 be due to scarcity of food, water or other causes, but con- 

 cerning this point we have no information. 



The culms of Bambusa spinosa and Bambusa vulgaris start 

 to grow during the latter part of the dry season, but make 

 very slow growth until the rainy season. Gigantochloa levis 

 starts to grow about the beginning of the rainy season. The 

 period of rapid growth is in the latter part of the rainy season. 

 Bambusa spinosa, Bambusa vulgaris, and Gigantochloa levis 

 reach about full height in approximately five months. This 

 means that for this period there is an average daily growth 

 in large culms of Bambusa spinosa of about 17 centimeters, 

 in Bambusa vulgaris of about 13 centimeters, and in Gigantochloa 

 levis of 13 centimeters. 



Beginning with 1912 and extending up to the present time, 

 measurements of the rate of growth of bamboos have been 

 taken by the Division of Investigation of the Bureau of Forestry 

 at Los Banos, Laguna, by means of a measured stick. The most 

 extensive series of measurements of large culms were made by 

 Ranger Oro in 1915. From this series we have selected for 

 presentation in the following tables all shoots of Bambusa spinosa 

 which reached a height of more than 20 meters, and of Bambusa 

 vulgaris and Gigantochloa levis which reached a height of more 

 than 12 meters. This selection has been made so as to repre- 

 sent the growth of only large commercial culms. 



In Table 8 are given the measurements of the rates of growth 

 of Bambusa spinosa. The first measurement was taken on June 



