270 STATE HORTICULTURAL SOCIETY. 



30-acre field lying south of this orchard produced between 29 and 30 bushels 

 of wheat per acre in 1888. I saw it fallowed in 1887, and the soil appeared 

 to be identical with that of the orchard. 



Orchard No. 16 has been remarkably productive, but has received very 

 little in the way of fertilizers. It is thirty-three years old, and never suf- 

 fered much from yellows until recently. This orchard may bo compared 

 with No. 2, which is on much the same kind of soil; or with No. 18, which 

 was not old enough to bear until 1888, and then produced only a sprinkling 

 of peaches, mostly premature; or with No. 3, which made a vigorous growth, 

 and bore only one or two light crops before succumbing. 



Again, on the supposition that yellows is due to exhaustion of soil, ought 

 it not to appear in old rather than young trees, in trees which have produced 

 excessive crops of fruit for many years in succession rather than in those 

 which have borne only one or two light crops or even none at all? The 

 reverse of this is true. I have found yellows more rapidly destructive in 

 young than in old orchards. I know a number of instances where very pro- 

 ductive old orchards have been entirely spared for the first fifteen or twenty 

 years, while young orchards on the same farm, or in the immediate vicinity, 

 have become very badly diseased during the first six years of their orchard 

 life. In some cases where soil, location, method of cultivation, etc., appeared 

 to be the same, I have found that old and young trees were attacked at about 

 the same time, both being injured alike, or the young suffering worst; in 

 other cases the young orchards have been attacked a year or two sooner than 

 the old ones. The reverse of this, i. e., old orchards attacked first, is some- 

 times true, but on this theory it ought to be true always, or at least very 

 commonly. This is certainly far from being the case. Of the eighteen orchards 

 specially mentioned in this report only four are over nine years old, and a 

 number of them have been set only three, four, and five years. 



A general consideration of the way in which the disease spreads appears 

 also to be opposed to the view that it results from soil exhaustion. Within 

 five or six years it has appeared in nearly all the orchards on the upper part 

 of the Delaware and Chesapeake peninsula, and for the last two or three 

 years it has affected tree after tree very rapidly. In that region it is now on 

 all kinds of soil, clay, clay loam, sandy loam, and light sand; on the richest 

 farms and on the poorest; on new and old lands; on impoverished hill tops 

 or hill sides, and in rich bottoms ; in young and old trees ; in budded fruit 

 and in seedlings; in transplanted trees and in those which have never been 

 moved; in trees crowded, set 20 feet apart, and even forty feet apart; on 

 moist fields and dry ones; on highly fertilized soils and on those which have 

 received a minimum of fertilizers or none whatever. These statements, every 

 one of which I have verified repeatedly in Maryland and Delaware, have also 

 all proved true in the experience of Michigan peach growers, as I know from 

 correspondence and conversation with many of them. Is it probable, or even 

 within the bounds of possibility, that iiuddenly all the orchard lands in whole 

 counties shf uld become exhausted and incapable of growing the peach; 

 capable still, however, of growing excellent corn and wheat, and fine vine- 

 yards and pear and apple orcliards? The chemical analyses of the peach 

 reveal no peculiarity of composition that would warrant any such belief. 



Moreover, in some of the lower counties of the Chesapeake and Delaware 

 peninsula, which have been settled as long and have grown peaches nearly or 

 quite as long, yellows has not appeared, at least not so as to be noticed, 

 although the soil is lighter and less fertile. 



