SEVENTEENTH ANNUAL MEETING. 6/ 



considered that at the present time we have no positive evi- 

 dence to show that yellows is transmitted in the blossom. 

 There must be, however, some normal method of infection — 

 possibly more than one, as in the case of pear blight. It may 

 be that it has methods of infection through the blossom and 

 other parts of the tree, as well, but this, like the cause, is still 

 a mystery. We are able to infect artificially by budding, and 

 there is no reason to doubt but that infected trees are pro- 

 duced that way in the 'nursery. On the other hand, old trees 

 remaining healthy for years, may go down with this disease, 

 especially when it infects new territory. 



Yellows on Nursery Stock. 



When a tree diseased by }-ellows, or any of the 

 vellows group, is used for budding nursery stock, 

 experimentally, the disease is invariably, or almost in- 

 variably, propagated. Naturally, well marked cases are se- 

 lected for this purpose. Smith budded yellows and peach 

 rosette successfully into both nursery and bearing trees. Re- 

 cently I have transferred the yellows and the little peach by 

 budding. In fact, one of the main reasons for concluding that 

 little peach was of the same group as the yellows was the man- 

 ner in which the budded trees behaved. They behaved the 

 same as the yellows, except their different symptoms were 

 developed. The question of the propagation of yellows by 

 means of buds from diseased trees seems an important one. 

 So far, all attempts to secure trees from diseased pits have 

 failed. Recently the writer planted 100 pits from trees well 

 marked with yellows and 100 pits from typical cases of little 

 peach. Neither of these grew. Not a single seed germinated. 

 In all cases where this has been tried, so far as I know, where 

 the pits were from well marked cases, a similar result has been 

 obtained. If this could be assumed to be always the case, it 

 would remove one great possibility of reproducing the dis- 

 ease. Unfortunatel}- we do not know what happens when 

 peach pits are taken from trees only slightly aifected or what 

 might be called incubating cases. That is, there still remains 

 the possibility of the reproduction from incipient cases which 



