200 STATE HORTICULTURAL SOCIETY. 



join the plum is three eighths to six eighths of an inch. They show no 

 symptoms of rosette or decline, while the parent tree is now affected in all 

 parts and already half dead. 



In another way this experiment establishes the same fact as No. 1, i. e, 

 the gradual transmission of a germ or virus of some sort from diseased to 

 healthy parts. Clearly something is now affecting the tissues of the north 

 part of the parent tree which was not in them one year ago. Otherwise 

 the forty-six peach shoots should now be diseased exactly like that part of 

 the parent tree. 



It is obvious that some years must elapse before this experiment is com- 

 plete, but enough has been observed already to make it almost certain 

 that the disease was not communicated by these buds. It is the same 

 kind of experiment as No. 4 of Part I. 



III. CONCLUSIONS. 



(1) The rosette, as now understood, differs from peach yellows in the 

 following particulars: 



(a) The more tufted character and somewhat different appearance of the diseased 

 growths. 



(b) The much greater tendency of these compactly, tufted growths to develop in early 

 spring from winter buds and to appear all over the tree. 



(c) A less tendency to develop sprouts upon the trunk and main limbs. 

 Id) The absence of premature fruit. 



(e) The general early fall of leaves and fruit on affected trees, the fruit being small, 

 yellowish green, and more or less shriveled and gummy. 

 (/) Gummosis of the roots. 

 (g) The occurrence of the disease in plums. 

 (h) The much more speedy destruction of affected trees. 



(2) The disease is virulently contagious (Experiment 1), and it is prob- 

 able that something might be done toward checking its increase by the 

 prompt destruction of all affected trees. This should be done in early 

 spring, as soon as the disease appears and before the leaves begin to fall. 



(3) The disease may exist for a short time in part of a tree without 

 being in the rest of it (Experiment 2), but it soon involves the entire tree. 

 In other words, it would seem from Experiment 2 that the cause of the 

 disease must enter the tree at some particular point or points and be 

 carried gradually to all parts through the circulation. A comparison of 

 the November and June examinations in Experiment 1 also confirms 

 this belief. 



(4) As in peach yellows, the admitted fact that neighboring trees are 

 not always the next to take the disease is no argument against its com- 

 municable nature. 



(5) This disease has gained a strong foothold and is on the increase, 

 especially in that part of Georgia known geoglogically as the Archaean. 



(6) If Georgia peach-growers would save their orchards and maintain 

 the successful cultivation of the peach, the necessity for prompt and con- 

 certed action appears to be very great. 



