8 



BULLETIN 3 3, POETO EICO EXPEEIMENT STATION 



LOCATION OF THE NURSERY 



In selecting a location for the nursery the water supply should 

 receive first consideration. An abundant supply should be available, 

 and overhead irrigation is very desirable. Preparation of the soil 

 should begin about a year before planting is done. The soil should 

 be deeply plowed and harrowed and then planted with a leguminous 

 crop. This should be plowed under when it has fully developed and 

 left for about three months to disintegrate. During this period the 

 soil should be harrowed frequently and any growth of Para grass 

 (Panicum barbinode) , or malojillo as it is locally called, should be 

 removed. 



Figure 1. — Grapefruit budded ou rough lemon stock and planted on extremely hard 



soil 



TREE STOCKS AND THEIR IDENTIFICATION 



In all citrus-growing countries opinion differs regarding the kind 

 of root stock to be used. This is natural in view of the fact that the 

 problem is complicated. In studying the stocks in the older groves 

 it was found that they consisted of lemon (fig. 1), sour orange (fig. 

 2), cultivated grapefruit, and some so-called native or wild grape- 

 fruit. They are growing in all the different types of soil and in 

 some of the groves in adjoining rows. 



Since the different stocks could not be identified except by means 

 of the sprouts (fig. 3) which arise from below the bud union and 

 are seldom present, it became necessary to find a* chemical method 

 permitting of readily differentiating one kind from another. The 

 method found is simple enough for planters to use. The following 

 directions will serve for field use : A piece of root from a tree carry- 



