PEACH YELLOWS. 261 



The braTiches on the tops of the trees were yet thickly covered with green 

 leaves, but the buds were well developed and the twigs had the appearance 

 of maturitv. On an average the trees in this orchard had lost about one- 

 fourth of their leaves. 



At Clayton, in un old orchard owned by Alfred Hudson, and considerably 

 injured by yellow?, the leaves had nearly all fallen by October i. The 

 early varieties shed first. Smocks and some other late sorts' retained quite a 

 sprinkling of green. On many trees in this orchard there was not a leaf, and 

 on an average about four-fifths of all the foliage had fallen. Such was sub- 

 stantially the condition of other bearing orchards examined at that time in 

 that locality. The young orchards were greener. Three days later I found 

 that the trees in the four-year old orchard of John Hudson (No. 9 of this 

 report) had lost from two-thirds to nine-tenths of their leaves. On some 

 varieties there were more leaves than on others. A one-year old orchard on 

 the same farm looked very green and retained most of its foliage. This was. 

 healthy in 1888, but No. 9 was badly diseased. 



On October 8 near Smyrna I examined two orchards, each about three or 

 four years old. They had shed from one-half or two-thirds of their foliage, but 

 the tops of many of the trees were still quite green. From my window at 

 Clayton I could also see another young orchard of many acres. The lower 

 two-thirds of what foliage remained was reddish brown, the upper third was 

 green. 



On October 10, near Clayton, in a very thrifty three-year old orchard 

 belonging to John Gault, I found that the trees still retained from one-third 

 to one-half their leaves. Fully one-third were yet entirely green and doing 

 duty. They were entirely gone from some shoots and from the lower one- 

 half to two-thirds of most of the shoots. The ends of many shoots still 

 retained all their leaves, although the buds in their axils would probably 

 have grown if taken for inoculation in August. My memorandum on this 

 orchard was: If frost occurs before October 20 it will catch the terminal 

 leaves, but I question whether the trees will suffer appreciably thereby. On 

 a partial examination at that time I found in this orchard twenty-five trees 

 with yellows, and many additional cases developed in 1888. 



Speaking for a majority of the young orchards about Clayton, in which 

 many new cases of yellows appeared in 1888, it may be said that from one-half 

 to three-fourths of the foliage had fallen by October 10, and in older orchards a 

 much larger proportion, although there had been no frost. 



Variety, age, situation, kind of fertilization, time and manner of cultivation, 

 and the production of fruit all have much to do in determining how early the 

 leaves shall fall. 



In 1887, judging by the number of leaves which had fallen, and by the 

 appearance of the young wood, it is reasonable to suppose that peach trees on 

 the Delaware and Chesapeake peninsula were well out of harm's way before 

 the first frost. If this is true of 1887, it is undoubtedly true also of 1885 and 

 1886,' and these frosts can not have been the cause of this outbreak of yellows. 

 Indeed, on general principles it may well be doubted whether even very early 

 and killing frosts will produce peach yellows. The burden of proof is all on 

 the side of those who support this theory. 



In Washington, D. C, especially where somewhat shaded or protected by 

 buildings, peach trees retained their foliage much longer than in the open 

 field. The first severe frost occurred October 16, at which time many of the 

 trees were yet in nearly full leaf. Between this date and October 30, especially 



