Recent Studies on Peach Yellows and Little Peach 59 



one site and become seriously diseased within 4 to 5 years when 

 planted on another with the two sites not more than one- fourth mile 

 apart. 



Propagation of Trees from Pits from Diseased Trees 



Pits from fruits which premature much in advance of the normal 



fail to germinate. The greater proportion of well-formed embryos 



from pits from trees with only one branch affected fail to germinate. 



Pits from branches only slightly affected may grow. However, 



all such trees produced at this station have proven to be healthy. 



Propagation with Buds from Diseased Trees 



It has long been known that buds from trees diseased with yellows 

 invariably reproduce the disease when budded into healthy stock. 



Comparatively little was known, however, about the time required 

 for the disease to incubate or develop in a tree. 



Some buds from a Fitzgerald tree at Vineland affected with yellows 

 in 1912 budded into healthy nursery trees in August resulted in ad- 

 vanced cases of yellows the following spring. 



One Fitzgerald bud failed to grow, but the bark united with the 

 healthy seedling tree and it developed advanced symptoms of yellows 

 the following summer as illustrated in figure 24. 



Buds from other trees affected with yellows did not cause ad- 

 vanced symptoms of the disease to develop on healthy stock for 

 several years. Observations indicate that different buds from the 

 same diseased tree and from different trees vary greatly as to the 

 virulence with which they transmit the disease. 



June Budding 



Diseased buds inserted into bearing branches of Belle of Georgia 

 trees in June had no apparent effect upon the trees that year. Fruits 

 only a few inches from the inserted diseased buds showed no in- 

 clination to premature. These trees all developed disease around 

 the inserted buds the next season. One tree developed little peach in 

 a branch where a yellows bud was inserted. 



An Occasional Healthy Branch May Occur on Diseased Trees 

 Buds taken from the apparently healthy parts of a diseased tree 

 almost invariably transmit the disease. Occasionally, however, a 

 tree is found on which a healthy branch occurs even after the promi- 

 nent symptoms of disease have appeared in other portions of the tree. 



