THINNING OUT OLD VINEYARDS AND ROOT-PRUNING 17 



ers be removed at one time, as this would check the growth of the 

 vine too much. 



6. Method. Thinning Out Old Vineyards and Root-Pruning. 



After the vines get about 15 years old and have quit extending 

 themselves, or as soon as, or still better, before the first signs of 

 the disease appear, I believe it best to thin out some of them, es- 

 pecially if they have been planted too close, as trees and vines gen- 

 erally are in California. This will give the remaining ones more 

 moisture during the latter part of summer and make the difference 

 between spring and fall moisture contents of soil less. These 

 should be root-pruned during the winter about half-ways between 

 the rows, which can easily be accomplished -by horse-power with 

 an implement, which could be devised for this purpose. On rich 

 ground, the only kind on which it would be necessary, the main 

 roots of Viniferas and of a good many American species are shal- 

 low, generally from 6 to 12 inches below the depth the plowing has 

 been done. 



It is best to plant vines at a greater distance than they gener- 

 ally are. From 10 to 12 feet each way for valleys and from 9 to 10 

 feet for mountains is not too far. The distance should vary accord- 

 ing to the richness of the soil, the richer and compacter this is the 

 greater the distance. It does not matter much, whether the tri- 

 angular or the square form is used ; the number of vines to the acre 

 will tell, whether there are too many or not. On very rich sand\ ; 

 or clayey loams in cool, moist localities, vines, which ripen their 

 fruit late, should not have quite the maximum distance, as this 

 would retard the maturity of the fruit. As soon as such plantings 

 are about 10 or 12 years old root-pruning should be practiced oc- 

 casionally. As this has a dwarfing effect on vines or trees and de- 

 creases their vigor, its usefulness will be seen. Smaller vines and 

 more space to hold reserve moisture for their proper maintenance 

 is the object desired. If root-pruning is omitted, the vines will in 

 course of time occupy the whole of the ground and make condi- 

 tions as bad as ever. There are single vines in the world that 

 occupy from one-half to one acre of ground. On poor gravelly 

 soils where vines make but small growth, root-pruning is not 

 necessary, as the vines have not enough vigor to extend their roots 

 through the whole of the ground allotted to them, if planted far 

 enough apart in the first place. No apprehension need be felt that 

 they will not produce as heavy crops per acre as with closer plant- 

 ing. These will be just as large if not larger and a better quality 

 produced. Although this will not come quite as soon, vineyardists 

 will be amply reimbursed in the saving of labor and other expenses. 



7. Method. Grafting Over of Old Vines. 



Grafting over a whole block, or still better, a whole tract of 

 vines, especially to more resistant Viniferas, is sufficient to post- 

 pone the disease for several years, because for the first time, since 

 attaining full growth, as the grafts start later and their growth is 

 generally smaller, they have plenty of moisture during the latter 



