Miscellaneous Products. 



242 



[September, 1908. 



again emphasizing the fact that the 

 limit of profitable fertilizing has been 

 reached with the third line. In the 

 lower half of the experiment plot, there 

 is a gradual decrease in the total from 

 the first to the fourth line, but this 

 may possibly be accounted for from the 

 fact that several of these plots received 

 fertilizers that proved injurious, and as 

 the amount was increased the injurious 

 effects were more pronounced. 



A study of the table will bring out 

 some other interesting facts. Sections 

 A, and B., both of which received acid 

 phosphate up to this year, each yielded 

 less than 100 pines, while section K. 

 which received the same treatment and 

 lime in addition yielded 162 pines, an 

 increase of over 60 per cent. ; this section 

 produced the highest number of 24's. 

 Section U., which was fertilized with dis- 

 solved bone black, dried blood and high 

 grade sulphate gave the highest yield 

 for this year, 168, while sections H. and 

 I. with 152 and 153 respectively, and 

 which received their phosphoric acid in 

 the form of slag, closely follow section 

 K. Section O., which also received slag 

 is next, with 147. Sections G. and J., 

 both of which received kainit, yielded 

 less than ten 24's, while section S. yielded 

 only one. 



The Freeze op 1905. 



After the freeze of February, 1905, the 

 experiment plot was carefully examined, 

 first by Mr. W. R. Hardee and later by 

 one oi' us (Blair) to see whether plots 

 fertilized differently had been differently 

 affected, but no marked difference could 

 be detected. True, some of the plots 

 looked worse than others, but they were 

 the plots that liad already been injured 

 by the treatment they had received. 

 Practically no difference, so far as the 

 effect of the freeze was concerned, could 

 be detected in the condition of those 

 plots which had responded well to the 

 treatment they were receiving. 



Although the crop for this year was 

 very much reduced, this statement is 

 weli borne out by the results. A further 

 examination of the table reporting the 

 crop for 1905 shows very clearly that the 

 most of those plots which have already 

 been reported as injured by the treat- 

 ment they Avere receiving, for example 

 sections A„ B., G., J., R. and S., gave the 

 lowest total number of fruits, or a very 

 small number of the larger sizes, or both. 

 Neither were we able to detect any 

 difference in the effect upon those plots 

 which received phosphoric acid, nitrogen 

 and potash in varying ratios. 



Remarks. 

 It was assumed that an average of * 

 and j of the total i phosphoric acid in 

 bone meal is available. 



According to the method used for 

 determining the available phosphoric 

 acid in slag, approximately J of the 

 total is available. 



Slag tends to produce a rank growth 

 of plants, and it is possible that if a part 

 of the slag should be replaced with bone 

 meal better results would be obtained 

 than with either alone. 



While land plaster was not used in 

 this experiment, except for one applica- 

 tion, it is used by a number of the 

 growers with good results. The claim 

 is made that it tends to aid in fixing 

 the nitrogen of organic fertilizers, such 

 as dried blood and cotton-seed meal. It 

 is considered especially helpful in this 

 respect if these organic fertilizers are 

 applied during a dry spell. This claim is 

 borne out by the work of a German 

 invenstigator.* He finds that land plaster 

 not only assists in the rotting of manure, 

 but that it also fixes or holds much 

 ammonia that would otherwise escape. 

 The conditions under which this investi- 

 gator worked are, of course, not the con- 

 ditions which exist in the pineapple belt, 

 but it is not at all unlikely that the same 

 chemical reactions take place. Those 

 growers who have used land plaster put 

 on about 200 pounds per acre. 



An effort was made, by analysis, to 

 find out whether the fruit would show 

 an increase in the elements of plant food 

 as the fertilizers were increased, but the 

 method of taking the samples tended to 

 vitiate the results. It was not possible 

 to make a composite sample of all the 

 fruit from each plot, and to take two or 

 three fruits from a plot, as was done, 

 probably does not srive average results. 

 The results obtained do not warrant us 

 in drawing any conclusions in regard to 

 the relation whicli exists between the 

 plant food in the soil and in the fruit. 

 Indeed, it is quite possible that increas- 

 ing the amount of plant food in the soil 

 may not affect the quantity to be found 

 in the fruit, but only that in the plant. 

 The results are of interest as showing 

 the amount of plant food removed by 

 the fruit and will be found in Table IV. 

 Given the weight of a crate of pineapples, 

 and the number of crates per acre, 

 it is a simple matter to calculate the 

 plant food removed by a crop of pine- 

 apples. 



* S. A. Sewerin, Gips als ammoniakbindende 

 Substanz bei der Verrottung des Stallmistes. 

 Centralblatt fur Bakteriologie, Par. u. Infek. 

 XI. Bd., Nos. 12-13 und 14-15. 



