September, 1908. J 



237 



Miscellaneous Products. 



acid phosphate contains sulphates of 

 iron and aluminum, and it is really the 

 presence of these astringent salts which 

 causes the injury. This view seems 

 the more correct when it is known that 

 acid phosphate derived from bone black 

 has no injurious effect on pineapple 

 plants. The application of lime with the 

 acid phosphate converts these injurious 

 sulphates into harmless insoluble oxides. 

 It is perhaps well to caution against the 

 use of dissolved bone black, inasmuch 

 as in many cases, high grade acid 

 phosphate, coloured with charcoal, is 

 on the market in imitation of the dissol- 

 ved bone black. It is well for one not 

 experienced in the chemistry of ferti- 

 lizers to use no form of acid phosphate 

 whatever for pineapples, but rely upon 

 bone meal or slag. This explanation of 

 the cause of the injurious effects of acid 

 phosphate on pineapple plants is not 

 given as a fact which has been fully 

 demonstrated, but as what seems to be 

 the most plausible explanation with the 

 evidence that is before us. 



Section L. was designed to find out 

 what is likely to prove the best ratio 

 for phosphoric acid, nitrogen and potash, 

 the four plots receiving the same kind 

 of fertilizer, but in different ratios. The 

 notes taken on this section from year 

 to year show that it has been a good 

 section and that the plots have been 

 fairly uniform in size, though the third 

 plot, No. 47, is recorded as being just 

 a little better than the others, and it 

 is of interest to note that the ratio of 

 phosphoric acid, nitrogen and potash on 

 this plot approaches very nearly the 

 ratio adopted for the experiment, and 

 further, as will be shown later, the 

 amount per acre— 3,750 pounds—is the 

 same as the amount that has given the 

 best results in general. 



Section M. is recorded as a good uni- 

 form section, and has given results that 

 compare very favourably with the best. 



Section N., as already noted, has been 

 discontinued on account of the injurious 

 effects of the acid phosphate and nitrate 

 of soda. It started off well but soon 

 manifested a tendency to "spike," which 

 tendency has been more or less apparent 

 during the entire time. 



Section O. has given good results, and 

 the plants have been fairly uniform, 

 with a healthy, vigourous appearance. 

 A comparison between the results from 

 this section and section M. , which differs 

 from it only in the source of phosphoric 

 acid, M. receiving bone and O. slag, will 

 show that O. has given practically the 

 c,ame results. 



Section P. has given good results, 

 though the injurious effects of the ni- 

 trate of soda have been noted to some 

 extent. The fact that a part of the 

 nitrogen was derived from the bone 

 meal tends to make these injurious 

 effects less than where nitrate of soda is 

 used as the only source of nitrogen. 



Section Q. has also been discontinued 

 for the reason just suggested, that is, 

 that nitrate of soda when used in suffi- 

 cient quantity to furnish all the nitrogen 

 proves injurious both to the plants and 

 to the shipping qualities of the fruit. 

 This section started off well, indicating 

 that the formula may be suitable for 

 getting young plants started to growing. 

 [For notes on sections R. and S. see notes 

 on page 420.] 



Section T. has been recorded as a good 

 section, with healthy, vigourous plants. 

 The results as shown by the crops com- 

 pare favourably with some of the sections 

 that have been classed among the best. 



Section U. has been a very uniform 

 section throughout, with healthy plants, 

 though the results, when judged by the 

 crop as given in the tables, do not indi- 

 cate that dissolved bone black could 

 replace bone meal or slag as a source of 

 phosphoric acid. 



The notes which have been "taken on 

 V. and W. from time to time state that 

 these sections are quite uniform through- 

 out, there being scarcely a perceptible 

 difference between the various i, plots of 

 the two sections. However, an examina- 

 tion of the tables of results will show 

 that the crops obtained from these sec- 

 tions do not exceed the crops from sec- 

 tions treated with the same fertilizers, 

 but which received only the two appli- 

 cations per year without variations. 

 This would seem to indicate that increas- 

 ing the number of applications per year 

 beyond two, or three, at the most, and 

 that varying the ratio of the fertilizing 

 ingredients with the different applica- 

 tions, as was done on section W.* are not 

 necessary after the first year. 



Section X. received the same treat- 

 ment as section C, except that each plot 

 received ten pounds extia bone meal at 

 the beginning. The section has been a 

 good one, and the plants have been fairly 

 uniform and in a healthy condition all 

 the time. However, the extra bone does 

 not seem to have given it any advantage 

 over those fertilized in the same way 

 but without the extra bone. 



* Beginning with 1905 the number of applications 

 for this section was reduced to two. 



