CITEUS DISEASES. 



85 



of its poor shipping qualities and other eonimercial defects, furtlier 

 extensions of the planting of this variety are out of the question, 

 even though its use would eliminate the scab. 



The two other varieties are both very subject to the disease, no 

 diffei'ence in their relative susceptibilities having been found, al- 

 though, in the opinion of some growers, the Marsh is less severely 

 attacked than the Duncan. Such differences as do occur from grove 

 to grove can be readily accounted for, it is thought, by environ- 

 mental or other local conditions. 



It has been stated ^ that certain non-citrus i)lants, the gandiil 

 {Cajanus indicus) in particular, are subject to the same disease 

 or one not distinguishable from it. No evidence was given to support 

 this theory, nor has any developed since, and it is, not believed that 

 any fears need ])e entertained that the disease is present on phmts 

 other than citrus. 



Appearance of the disease. 



Citrus scab attacks the fruit, leaves, and young twigs. 'IMic 



Fig. 10. — Citrus f^cal) on young gia|)i>fruit. 

 * 



first signs of infection are circular, minute, translucent areas, fol- 



' Report Agricultural Experiment Station, MayagUez, 1911. 



