PEACH YELLOWS AND PEACH ROSETTE. 175 



The buds for inoculation were selected with the greatest c'are from seven- 

 teen diseased trees in the older orchard of James W. Green, Magnolia, 

 Delaware (No. 14 of first report). I did not have an orchard map when 

 the buds were cut, but, judging from the appearance of the trees, all were 

 cases of 1889. Each one was plainly diseased by yellows, but none were 

 wholly diseased, i. e., none appeared to be so. One third to one half of 

 each tree was more or less yellow and bore the diseased shoots, but the 

 other side was green and thrifty and although examined very minutely 

 gave no indication of disease. Two shoots were taken from each tree 

 (different limbs). These were two to three feet long, robust, well matured 

 for the time of year, and to all appearances perfectly healthy. Each shoot 

 came from the healthy-looking side of the tree, and all bore smooth, green, 

 and vigorous leaves, six to nine inches long. Better looking buds were 

 never used. These shoots grew out at much greater distances from dis- 

 eased parts than those used for Experiment 2. They were cut July 18. 

 1890, immediately stripped of foliage, and wrapped in damp cloths. Row 

 1, was budded July 19; row 2, July 21; and row 3, July 22. All of the 

 buds were used except some on the base of the shoots which proved too 

 large for the stocks. Two buds were put into each seedling, but owing to 

 dry weather and unskillful manipulation, many of them failed to unite 

 with the stock. Others healed on satisfactorily but made no growth. Still 

 others made a growth of one to ten inches >although the upper portion of 

 the stocks was purposely left uncut in order to prevent this. 



The stocks were healthy (December 13, 1890), and it was only the few 

 buds which had already developed into shoots that I desire to notice here. 

 None of these appeared to be perfectly healthy, and some of them had 

 developed very characteristic symptoms of yellows. Since then there 

 have been new developments. At this date (July 16, 1891), twenty-eight 

 stocks show symptoms of yellows, and the foliage on five or six vigorous 

 shoots, which have grown from inserted buds, begins to take on a peculiar 

 yellow tint very suggestive of this disease. There are cases in each of the 

 rows, but most at present in the S. row. 



This experiment is, in part, a repetition of No. 2. Whether these trees 

 (the stocks) will all perish in the same way remains to be seen. Another 

 point important to be settled is whether any of the inserted buds will 

 develop into healthy trees. The seedlings will be transplanted at an early 

 date to a locality entirely free from yellows and kept under observation 

 until this can be determined. 



III. EXCISIONS. 



Symptoms of peach yellows, as already noted, frequently appear at first 

 on one branch only, or on one side of a tree, while the rest remains for 

 several or many months, to all appearances, perfectly normal. The symp- 

 toms of the disease are progressive from part to part until the whole tree 

 is involved, and this has favored the idea that the disease is local at first 

 and only constitutional or universal after the lapse of considerable time. 

 Generally, in bearing years the earliest plain symptoms are found in the 

 fruit, and this fact has led to a strong popular belief that the disease is 

 communicated from tree to tree by pollen, through the instrumentality of 

 bees or otherwise. There is, however, absolutely no foundation in observa- 

 tion for any such belief. The following experiments were undertaken in 

 the hope of determining whether the disease is local or constitutional 



