34 N. J. Agricultural Experiment Stations Bulletin 356 



The peculiar mottling, yellowing and checked growth due to the un- 

 known soil factor can be distinguished from yellows and little peach 

 by the eye, after one has become familiar with it. 

 The difference can be determined also by a starch test of the foliage in 

 early morning. The foliage behaves normally in that the starch is 

 completely transferred at night while in yellows and little peach 

 foliage there is an accumulation of starch. 

 9. Little peach in bearing trees can usually be distinguished from other 

 troubles which resemble it by the combination of symptoms of the small, 

 below-normal and late-ripening fruit and the characteristic drooping 

 yellow green foliage. 



10. The peach "buttons" described on page 18 can be readily distinguished 

 from little peach by the fact that some normal fruits are found with the 

 "buttons." If all the fruits should happen to be "buttons," the foliage 

 should still appear normal, thus clearly distinguishing it from little peach. 



11. In some cold, wet seasons the fruits of some varieties such as Mountain 

 Rose and Lola remain exceptionally small and if the soil is heavy or not 

 well drained, or if there is a lack of nitrogen, the foliage may also 

 appear light green or yellow thus resulting in symptoms quite similar 

 to those of little peach. One should be cautious about removing trees 

 under such conditions. 



Propagation of Trees from Pits from Diseased Trees 



Observation by a number of workers indicate that very few pits 

 from diseased trees grow, and that there is likely to be little danger of 

 the distribution of the disease in the use of pits from diseased trees. 

 At the time this work was done, however, less prominence had been 

 given to the fact that yellows may possibly be present in trees for a 

 long period of time, before advanced symptoms of the disease ap- 

 pear. This raised the question whether pits from such trees might 

 not germinate and carry the disease. 



Pits which had been collected from trees in advanced stages of yel- 

 lows and also from trees having only one branch showing marked 

 symptoms of disease, were planted in various ways. Pits saved from 

 from branches showing prominent symptoms of the disease, and 

 where the fruit prematured much in advance of the normal season, 

 were usually without embryos and of course failed to grow. How- 

 ever, some of the pits from trees in the early stages of yellows which 

 contained well formed embryos, failed to germinate when placed either 

 in the greenhouse or outdoors. Some essential factors appeared to 

 be lacking in the seed. 



In the spring of 1913, a considerable number of seedling trees were 

 found growing under a Ray tree affected with yellows at the High 

 Bridge orchard. This tree had been under observation from the 

 time it was planted in 1906 and produced premature fruits in 1911 

 and 1912. From the fact that the tree was affected with vellows. the 



