PINEAPPLE CULTURE IN SOUTH AFRICA 



that "many plantations have been put out on Shell laud, but have 

 uniformly failed." As this so-called shell land is largely com- 

 posed of Carbonate of Lime, this was a further proof of the 

 cause of Chlorosis. 



THE SOIL OF THE KEYS. 



Samples of soil were then obtained from two of the Keys, 

 Two from each, Mr. T. J. Johnstone of Planter, whom the writer 

 well remembers as a Pineapple grower over 20 years ago, and Mr. 

 E. Gottfried of Key -Largo. All these four samples showed high 

 percentages of lime and extremely high percentages of organic 

 matter. These two Keys are probably the first two on which 

 pineapples were grown for commercial purposes and as pine- 

 apples were an unqualified success there, the presence of the 

 Lime in the soils would at first sight appear to upset the theory 

 that lime was the cause of " Chlorosis ". 



ORGANIC MATTER AND NITROGEN. 



Finding the conditions above-mentioned were not injurious, 

 certain plots were planted in order to determine whether the 

 presence of Organic matter and nitrogen in large proportions 

 would act as an antidote to the excess of lime ; at the same time 

 plants" -were grown in pots with similar soil to that in the field 

 trials. The results conclusively proved that the pineapple will 

 grow in almost any soil, but that the addition of Carbonate of 

 lime, except to soil which .has purely organic matter, in every 

 case produced " Chlorosis ". In the case of the test of a soil of 

 pure organic matter it was found that an addition of as much 

 as 50 per cent, of Carbonate of Lime was not in.iurious. but 

 amounts beyond that brought on Chlorosis. 



RESULT OF THE TESTS. 



The conclusions arrived at from these investigations are, that 

 in a loose sandy soil, the presence of 2 per cent, of Carbonate 

 of Lime renders such soils unfit for pineapple cultivation; pos- 

 sibly if such soils contain at the same time a good proportion 

 of humus, they might produce healthy growth; the danger limit 

 of loamy soils may be a trifle higher. It should be noted that 

 the only loamy soil producing Chlorosis plants contained 4 : f>2 

 percent of Carbonate of Lime. 



TREATMENT ADOPTED. 



The only treatment which enabled the plants to regain their 

 normal healthy appearance was the application of iron in liquid 

 or other readily soluble forms, either to the roots or to the vege- 

 tative portion of the plant, these experiments however, prove 

 this was not a commercial proposition. 



