REPORT OP COMMITTEE ON PUBLICATION 105 



sweet, well-flavored or firm or highly colored as those grown with less water. 

 The amount of water applied will vary from two to six acre inches, depend- 

 ing upon the subsoil. 



If one irrigation is given it is applied about two weeks before the fruit 

 ripens. If the fall is a dry one, another irrigation is given after the leaves 

 fall. 



In the St. George district if clean culture is practised, three irrigations 

 per year will be ample, unless extremely hot dry winds prevail for protracted 

 periods, or the fall, winter and spring are unusually dry, in which event 

 another irrigation will be necessary in February or March. These irrigations 

 are applied at blooming time, one or two weeks before ripening and after the 

 leaves fall. 



Drainage. In most Utah sections, the vineyards are so located that 

 artificial drainage is not necessary. In one section, however, it has been 

 found that on deep, sandy soil where grapes have grown for five or six years, 

 that their roots have gone down over eight feet. Under these conditions it 

 can be seen that ordinary drainage measures would not save a vineyard, 

 unless the drains were placed very deep. 



Fertilization. No fixed or universal system of manuring has been 

 adopted, though many receive barnyard manure at irregular intervals. This 

 is true in parts of the St. George district, especially where light sandy soils 

 are found. Here it has been found, especially on Thompson Seedless, that 

 by leaving two or more canes the vines can be manured heavily and large 

 quantities of grapes will be produced without an excessive wood growth. 



Alfalfa, crimson clover, sweet clover and rarely hairy vetches are the 

 green manures used. 



Treatment of the Vine. 



The Concord is the variety mostly grown in the north, while small areas 

 are devoted to the Black Pearl, Sweetwater, the various Muscats, Thompson 

 Seedless, Flame Tokay, Black Cornichon, Malaga and Feher Szagos about in 

 the order named. 



In a few instances the vines have been propagated by cuttings. Most 

 of them, however, have been imported. 



Pruning. Throughout the State most of the pruning is done in the 

 spring, the amount depending upon the grower and to some extent on the 

 variety. The largest growers in the north prune their Concords to fifteen 

 or twenty spurs of three buds each. Other growers advocate the leaving 

 of more wood and where the soil is rich it unquestionably gives greater 

 yields with but slight difference in the size of the berry. 



About half of the vines in the north are trained on trellises, the rest 

 to a low stump form barely a foot above the soil. 



In the St. George district, practically all of the vines are trained to the 

 stump form, the crown being one and a half to three and a half feet from 

 the surface. Here spurs of two or three buds are left and as many as the 

 vigor of the vine will justify. 



In a co-operative pruning experiment at St. George, the writer increased 

 the yield of Thompson Seedless grapes from 12 to 24, 27, and 29 pounds per 

 vine by leaving two, four and six canes of 10 buds each on the vines in 

 addition to the spurs that would normally be left. 



