September, 1911.] 



219 



Edible Products. 



of shallow cultivation. Six months 

 after the act it seems clear that our 

 trees are more vigorous as a result of it. 

 Surface ploughing results in the develop- 

 ment of a root system at a greater 

 general depth; and assuming freedom 

 from stagnant ground water this is an 

 advantage, for it tends to secure 

 immunity from drought. Moreover, 

 some measure of surface cultivation is 

 necessary for the controlled and rational 

 use of fertilizers or of irrigation. The 

 grove is now kept in decent condition by 

 the occasional use of the disc harrow at 

 very slight expense, and without even 

 temporary bad effect on the trees. 



Effect of Fertilizers. 

 Half of the grove in charge of the class 

 was fertilized Sepetember 9, each tree 

 receiving 6 kilo of basic slag containing 

 20% P2 05, and 0"8 kilo of kaiuit contain- 

 ing 13'50% K2 0. These fertilizers were 

 donated by Behn, Meyer and Company 

 of Manila for this experiment. For 

 reasons developed elsewhere in this 

 paper, an application of fertilizer to the 

 coconut is not likely to reach its 

 maximum effect until at least eighteen 

 months, and perhaps as much as three 

 years after it is mide. The fertilizer 

 was scattered over ground already 

 ploughed, and was then harrowed in. It 

 must first enter the plant in appreciable 

 quantities, and this takes some time 

 before it can begin to have any influence. 

 If it then hastens the building of leaf- 

 rudiments, this effect can be seen only 

 after a year and a half, or more ; and 

 the nuts borne in the axils of these 

 leaves will not be ready to harvest with- 

 in three years. 



However, if the fertilizer is going to 

 have much effect, this must appear more 

 immediately in acceleration of the 

 growth of the leaves. If it results in 

 more rapidly growing and larger leaves, 

 and so in increased photosynthesis and 

 transpiration, the fertilizer is likely to 

 have ultimate indirect influence on the 

 production of nuts, more important 

 perhaps than its direct effect can be. As 

 a matter of fact, its influence on the 

 growth of the leaves is already evident. 

 During the first week in March I have 

 had measurements made of the growth 

 of the leaves of all the normal trees 

 under observation, fertilized and unfer- 

 tilized. Trees attacked by beetles, and 

 a few trees younger than the others, 

 have been left out of account for the sake 

 of uniformity. 



The following table shows some of the 

 results of these measurements. The 

 first part of it is compiled from measure- 

 ments by M. B. Raynmndo 



Table VI. 



Avergae Daily Growth of Leaves, 





Fertilized Trees. 





Leaf Tree 1 



£ 3 



4 



o u 



T 

 1 



10-71 



55 3-14 



1-88 





TT 

 11 



10'42 



5-0 3-0 



1-5 



0-57 0-28 



TTT 

 111 



10-00 



2-85 1*71 



10 



0-45 0-28 



TV 

 1 V 



10-28 



6-14 broken ... 





V 

 V 



8-42 



3-28 1-71 



0-88 



0-36 0-14 



VI 



V 1 



5-00 



2-28 1"28 



0-61 



0-7 0-14 



VIT 

 V 11 



7-07 



1-21 0-44 



o-ii 



0-04 0-00 



•Average 



8-84 



3-74 1-88 



1-00 



0-41 0-19 





Unfertilized Trees. 



I 



3-07 



2-0 0-8 



0-17 



not 









measured. 



II 



4-67 



3-57 1-57 



0-46 





III 



3-64 



2-17 0-6 



0-04 





IV 



5-35 



3-71 221 



0-71 





V 



4-28 



3-28 2'02 



1-71 





VI 



3-35 



1-8 1-07 



0-28 





VII 



6-85 



5 '25 3-51 



1-42 





Average 



4-47 



3-12 1-69 



0'68 





Results of Cevallos, 6 trees each, ferti- 

 lized and unfertilized. 



Fert. 28-8 16'6 6-8 21 



NorFert. 266 15-8 3-7 1'6 



Lijano found the average growth of 

 the youngest of his fertilized trees to be 

 27-9mm, and of the unfertilized trees 

 20 -8mm. 



Two geueral conclusions can be drawn 

 from these determinations ; — 



1. The average growth of all leaves of 

 fertilized trees is greater than that of 

 unfertilized trees. 



2. The greater difference is to be 

 noted in the older leaves. This indicates 

 that the leaves of fertilized trees con» 

 tinue to grow for a longer time. This 

 may have as much as the more rapid 

 growth to do with the ultimate greater 

 size of the leaves, and so the greater 

 vigour of the tree. 



The Spathe, 

 The growth of the spathe is a matter 

 of general interest as a part of the 

 general growth of the tree, and of special 

 interest to tuba producers since the 

 spathe is the source of the crop. The 

 spathe ceases to elongate shortly before 

 it splits open- This is usually from 75 

 to 90 days after the first appearance 

 of its tip. The total length of the 

 visible part of the grown fertile 

 branch is usually between seven and 

 nine decimeters. The rate of growth of 

 all spathes measured has risen at times 

 more than 2 centimeters a day ; but the 

 average including periods of depression, 

 and the final period of ;little or no 

 elongation is only half of the maximum, 



