LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 



Bureau of Plant Industry, 



Office of the Chief, 

 Washington, D. C, January 5, 1908. 



Sir : I have the honor to transmit herewith and to recommend for 

 publication as Bulletin !S T o. 125 of the series of this Bureau the ac- 

 companying manuscript, entitled " Dry-Land Olive Culture in 

 Xorthern Africa.'* 



The culture of the olive without irrigation in a region where the 

 average yearly rainfall is only 9.3 inches is the most highly suc- 

 cessful example of dry- farming methods applied to a tree crop of 

 which we have any knowledge. It has long passed the experimen- 

 tal stage, having been carried on in southern Tunis with the methods 

 now in use for at least fifty years and having been developed on a 

 vastly more extensive scale in the same region during the early cen- 

 turies of the Christian era. 



The description here given of the methods and of the type of tree 

 adapted to this system of culture will be of special interest to that 

 portion of the southwestern United States where olive culture is pos- 

 sible. But it also concerns arid and semiarid regions outside of the 

 olive zone where arboriculture, based upon other crops, seems des- 

 tined to become an important feature in dry-land agriculture. The 

 present paper should stimulate the search for useful trees capable of 

 being grown profitably under dry-farming conditions. 



In the course of an expedition to Tunis for the Office of Seed and 

 Plant Introduction and Distribution, the primary object of which 

 was to obtain promising varieties of dates for trial in the south- 

 western United States, Mr. Kearney spent several weeks in the dry- 

 land olive-growing districts studying the methods used and the 

 conditions under which the culture is there carried on. This was 

 done at the suggestion of Mr. W. T. Swingle, of this Bureau, who 

 has charge of investigations in dry-land arboriculture. 



The drought-resistant variety of the olive that is grown in Tunis 

 has been introduced with a view to establishing dry-land olive culture 

 in the United States. Investigations along this line will be carried 



