OLIVE ORCHARDS OF SFAX. 



19 



per cent) . According to Trabut," a high lime content is a very favor- 

 able factor in growing olives for oil production, as olives produced 

 in limestone regions are richer in oil and the oil is of better quality 

 than where the soils are deficient in this component. It should be 

 noted that while the nitrogen and phosphoric acid content of the 

 Sfax soils would be considered low for most crops, the high yields 

 and good quality of the oil produced at Sfax are sufficient evidence 

 that the supply of these two elements of plant food must be amply 

 sufficient for the requirements of the olive. This can perhaps be 

 explained by the fact that the roots of this tree occupy so great an 

 area of soil (one-seventh to one-tenth acre) that while the percentage 

 of these elements to weight of soil is everywhere low the total amount 

 available to the roots is actually rather high. 



THE OLIVE ORCHARDS OF SFAX. 



THE VARIETY GROW T N. 



The Sfax orchards contain only one oil-producing variety, the 

 Chemlaly, 6 to which probably at least 95 per cent of the trees belong, 

 the rest being varieties with larger fruits used for pickling. The 

 fruits of the Chemlaly are very small but are produced in great quan- 

 tity (Plate III). They are exceedingly rich in oil, yielding 30 per 

 cent in factories where modern presses are used and as high as 34 J 

 per cent in extraction experiments made by the chemist of the Tunis 

 government. These are unusually high percentages, but they are at- 

 tributable, perhaps, more to the heat of the climate than to a pecu- 

 liarity of the Chemlaly variety, for still farther south in Tunis the 

 olives are even richer in oil. In the extraction experiments above re- 

 ferred to, olives grown in the celebrated oil-producing district of Bari 

 in southern Italy yielded only 28.2 per cent. In European countries 

 near the northern limit of olive production the fruit is said to yield 

 only 13 per cent of oil. 



Oil made from the Chemlaly variety is very pure and of excellent 

 flavor. For commercial purposes, however, it has a serious defect in 

 its high content of stearin, or fixed acid, which causes it to congeal 

 at relatively high temperatures. This characteristic renders Sfax 

 oils difficult to sell in northern Europe, and it is especially prejudicial 

 to their use in preserving sardines, etc. It is not, however, an insuper- 

 able objection, since the excess of stearin can be removed at a rela- 

 tively small expense. 



aTrabut, L. L'Olivier, Bui. 21, Service Bot., Gouvernm. Gen. Algerie, 1900, 

 p. 43. 



b Five or six very different varieties, all known as Chemlaly, occur in Tunis. 

 That grown at Sfax is commonly designated as the " Chemlali de Sfax." 

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