Page:A Practical Treatise on Olive Culture, Oil Making and Olive Pickling.djvu/78

 engender most of the diseases of fruit trees, it has not to dread such terrible enemies as those that assail the vine, from the Oidium to the Phylloxera, which, alone, within the last twenty years, has brought down the French wine production from 85,000,000 hectolitres (about 2,000,000,000 gallons) to 25,000,000 (about 625,000,000 gallons) and which crops slowly and relentlessly on among our California vineyards.

During the excessively dry summers which are occasionally seen in part of California, when all the other agricultural productions are affected and diminished in consequence, the olive tree, this king of the dry soils, where it vegetates best, will continue to be loaded with fruit, just as in the seasons most favorable to other cultures.

The spring frosts, so disastrous generally to valley land vineyards, seem to have no effect on the olive. The tree is often affected and even killed in the best oil regions of Europe by excessive cold spells, which are absolutely unknown in our parts of California, so that its culture, which offers great danger there, and keeps it from being more developed, presents an unquestionable safety in Napa Valley and such other sections where there is no danger of such extremes of cold or hot weather, both of which the olive tree fears to an equal degree.

Finally, while an olive grove planted with one year old rooted cuttings pays, when five and six years old, quite as much as a vineyard of same