434 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Citrus buds are naturally inclined to make two growths from the same 

 Dud ; this should be watched for and the weaker one removed so as to get 

 the entire strength into the single growth. 



Stocks and Mal-di-goma. 



The following stocks are available for the working of Citrus trees : — 

 The Rough Lemon (C. Limonum), Sour Orange (C. vulgaris), Sweet 

 Orange (C. Aurantium), Seville Orange (0. Bigaradia), and Shaddock 

 (C. decumana) ; of these the Seville and Sour Oranges, and the Rough 

 Lemon have given the best results in general cultivation in the West 

 Indies. These give the planter a fairly wide range of choice of the stocks 

 most suitable for his particular purposes. 



Stocks should, in the first instance, be chosen with a view to their 

 immunity from disease. Mal-di-goma, or Root Rot, which broke out in 

 the groves in Europe some sixty years ago did considerable damage to the 

 trees, and has now spread to almost every Citrus-growing region through 

 out the world. Some stocks appear to be very susceptible to the disease, 

 whereas others are, to a greater or lesser degree, immune. Therefore, 

 disease-resisting stocks should be chosen, and not budded lower 

 than one foot above the soil. This disease, however, can be kept in 

 perfect check if care be taken to see that there is effective drainage, and 

 that sunlight is allowed a free entrance to the base of the stems. 



The Sour Orange is a good hardy stock, and is not subject to root 

 rot. It does not do well on a dry soil, but thrives on good retentive 

 soils such as are found in forest or interior lands. 



The Washington Navel Orange thrives remarkably well on this stock, 

 as does the Grape fruit. It is more extensively used as a stock than any 

 other for Citrus trees in the West Indies. 



The Seville Orange, like the Sour, is immune from root rot, and thrives 

 best at low altitudes, and requires a larger amount of root moisture than 

 the Lemon or Sour Orange. 



The Rough Lemon is not suitable for low altitudes ; it thrives best on 

 high, dry soils. It is considered by some to be unaffected by root rot ; by 

 others it is said to be subject to the ravages of this disease. The root 

 system of the Lemon being specially adapted to high and dry situations 

 makes it unsuitable for the lower altitudes where root rot is prevalent. 

 Should this stock, therefore, be used in low situations where large quantities 

 of moisture are present it is quite conceivable that the Lemon would prove 

 a failure and fall a ready victim to this disease. This is possibly the 

 cause of these conflicting opinions. This stock possesses a good foraging 

 root system, which makes it very serviceable in poor soil containing little 

 plant food. The growth of trees on this stock is much more rapid than 

 on the Sour or Seville Orange. The Grape fruit does exceedingly well on 

 this stock. 



The Shaddock is also a good hardy stock suitable for dry soils, and 

 proves a good substitute for the Rough Lemon in every way. 



The Sicect Orange is not as hardy as the sour, but the growth of trees 

 on this stock is more rapid than on the sour. This stock is, however, 

 susceptible to root rot. 



