634 FRUIT CDLTUEE IN FOREIGN COUNTRIES. 



annnally more tban 3,000,000 francs' worth of olives. Its larva, intro- 

 duced into the flower of the fruit in the form of an almost impercep- 

 tible egg, hatches in the fruit, and is nourished by its substance. In 

 September the larva, becoming a perfect insect, issues from the olive, 

 cutting and weakening, the little stem which joins the fruit to the branch. 

 The fruit, when this happens, soon falls in a spoiled and unripe con- 

 dition, and the oil it produces is rancid to the taste, and only valuable 

 for the lamp. 



Diseases. — The olive tree does not escape from vegetable parasites. 

 A tree infected with morplua or fumago becoaies all black — trunk, 

 branches, and leaves. If it produces fruit, which rarely occurs, such 

 contain no oil. This disease once fastened, lasts about ten years, and 

 it is without a known remedy. Severe pruning in such cases is some- 

 times practiced, but it is usual to leave recovery to the operation of 

 time. . Twenty years ago, this disease wasted many groves in the envi- 

 rons of Grasse and at Beaulieu, but finally disappeared. Eecen^ly 

 the environs of Cette have been afiQicted with that sickness. Some 

 proprietors said it resulted from the fog, others ascribed it to emana- 

 tions of the soil, and others to the wind from the sea. M. Aug. Riviere, 

 an expert in such matters, is of opinion that the disease develops from 

 the honey matter deposited under the leaves by the insects Aphis coccus 

 or Kerines. Among the numerous remedies for the scourge have been 

 hyi)osulphite of lime, petroleum, and fumigations of tar, all of which, 

 however, have been found useless. The same disease occurs among 

 the trees in Spain, under the name of negruro. 



Secondly, the decay of the olive. Among trees not too thickly 

 planted and on lean, dry soils this seldom occurs, but elsewhere is 

 quite noticeable. The decay arises, for the most part, from the cuttings, 

 the breakings, and the bruises to which the tree is subjected. The 

 wounds thus made, unless protected from the air, cause the ligneous 

 substance to become rotten. This disease proceeds, undoubtedly, to a 

 large extent from the method in which many of the young plants are 

 obtained. These, when extracted with a few horizontal roots from the 

 foot of the parent tree, leave injuries inviting decay. The treatment 

 for the trouble consists in removing the decayed portions as much as 

 possible, and closing the cavities with mortar of sand and lime. 



Cost and profits. — On slopes or undulating fields 1 hectare of land 

 (2.47 acres) usually contains about 200 olive trees ; on plains about 150. 

 To calculate as exactly as possible both the expense and yield in this 

 district, I will make an average of both situations, observ ing, at the 

 outset, that the crop is biennial, and that in the estimates of expenses, 

 therefore, only one-half is to be taken. 



To cultivate a hectare on plains it is necessary to dig and loosen the 

 soil, a labor of fifty days at 48 cents per day, one-half of which sum is 

 $12,06; to manure the same (150 trees at 14.4 cents each), $31.71 ; to 

 prune the same, at 19.3 cents per tree (the halt'), $14.48. Each tree 

 gives, on an average, three double decaliters of fruit, equal to 13^ gal- 



