CROPS OF THE COLONY. 63 



where the rainfall is siiiali. The Hrst irrigation in .summer generally 

 takes place when the grapes ])egin to color, and the second about two 

 weeks before the vintage. About '2 acre-inches of water is used in 

 flood irrigation, but only about li acre-inches in furrow irriga- 

 tion. It is desirable to follow each irrigation by a cultivation, in 

 order to keep down weeds and prevent the surface of the soil from 

 baking. 



Nitrogenous fertilizers are needed in maintaining the wood growth 

 of Algerian vineyards, and phosphoric acid is also often required to 

 promote productiveness. Farm manure is nuich used and is applied 

 at the rate of 12 to 18 tons per acre. 



When wine making first began in the colony great difticulty Avas 

 experienced in completing fermentation, and the (jualit}^ of the wine 

 was nmch impaired by the presence of unfermented sugar. This 

 was due to the high sugar content of the Algerian grapes and to 

 the high temperatures prevailing during fermentation. These diffi- 

 culties have been largely overcome, however, by observing certain 

 precautions. If the weather during the vintage is very hot, the grapes 

 are gathered and put into the vats in the early morning while they 

 are cool, and the temperature of the vats is kept down by causing 

 cool water to circulate on the outside of them. 



The fungous diseases, such as anthracnose, oidium, and mildew, which 

 attack vines in Algeria, have been more or less successfully kept in 

 check by spraying. Not so, however, with phylloxera, which has 

 wrought terrible havoc in the vineyards of Oran and Constantine 

 departments since its first appearance in the colony in 1883. A very 

 rigid inspection law has failed to put a complete stop to its ravages. 

 The practice of flooding infected vineyards, which has given such 

 happ3' results in southern France, can not be generall}^ adopted in 

 Algeria because of the scarcity of irrigating water. So far the vine- 

 yai'ds of the central department, that of Algiers, have escaped damage 

 from this destructive insect. 



In the vineyards of western Algeria consideral)le losses have been 

 sustained through the rise of salts in the soil. The effect of salt in 

 the soil upon Algerian vineyards has been discussed by Dugast (see 

 p. 4-1 of this report), who calls attention to the existence of occasional 

 more resistant plants. In some districts the vines have been killed, 

 while in less extreme cases the quality of the wine has been much 

 impaired by taking up more or less of the salt contained in the soil. 

 A French law forbids the sale of wme containing more than one part 

 per thousand of sodium chlorid, but in some of the wine produced in 

 Oran Department thi> percentage has been exceeded. It is considered 

 safe to plant vines in any soil that is not too salty to permit a good 

 growth of flgs, pomegranates, alfalfa, or artichokes. 



