308 IRRIGATION FARMING. 



vines are bearing heavily they may be watered more 

 liberally. However, even then no more than two irri- 

 gations are recommended forcompadl soils. And even 

 in the lightest and sandiest soils irrigations at periods 

 less than ten days are not pra(5licable. On these light 

 and sandy soils, however, irrigation must be much 

 more frequent than on heavier ones. 



The European varieties are especially susceptible to 

 over-irrigation. They are not slow in calling a halt 

 where too much surface water is applied. The vines 

 grow fast and appear to be doing well under repeated 

 irrigations; but the fruit is pra<5lically a failure. 

 Where there is any moisture in the soil from fall irri- 

 gation or winter rains it is advisable to delay irriga- 

 tion till the fruit is forming, and then apply the water 

 but once or twice at the most. Never irrigate during 

 the opening of the flower, the least possible during the 

 days before, and by preference irrigate when the fruit 

 begins to enlarge. For inexperienced people, it is 

 more prudent to irrigate in trenches passing near the 

 plants, and not by flooding the whole surface of the 

 ground. 



One must introduce in the soil alternately much 

 air and little water. Take as a guide for cultivating, 

 the state of the soil; and for irrigating, the condition 

 of the plant. These very simple principles are not 

 generally understood by those who have not pra<5liced 

 irrigation — they give too much water and too little 

 cultivation, and, above all, give them at improper 

 times. Subsurface irrigation is well adapted to grape 

 culture, as the roots all penetrate to great depth. 

 Where underground pipes are laid near the foots of 



