THE DISEASES OF THE PEACH TREE. 41 



by little, the Yellows spread from its original neighborhood, below Philadel- 

 phia, to the whole northern and eastern sections of the Union. At this moment, 

 1845, it is slowly bnt gradually moving West ; though the rich and deep soils 

 of the western alluvial bottoms will, perhaps, for a considerable time, even 

 without care, overpower the original taint of the trees and stones received from 

 the East. 



Let us look a little more closely into the nature of this enfeebled state of the 

 peach-tree which we call the Yellows. 



Every good gardener well knows that if he desires to raise a healthy and 

 vigorous seedling plant, he must select the seed from a parent plant that is 

 itself decidedly healthy. Liijdley justly and concisely remarks: "All seeds 

 Avill not equally produce vigorous seedlings; but the healthiness of the new 

 plant will correspond with that of the seed from which it sprang. For this 

 reason it is not sufficient to sow a seed to obtain a given plant ; but in all cases, 

 when any importance is attached to the result, the plumpest and healthiest 

 seeds should be selected, if the greatest vigor is required in the seedling, and 

 feeble or less perfectly formed seeds, when it is desirable to check natural 

 luxuriance.'"* 



Again, Dr. Van Mons, whose experience in raising seedling fruit trees was 

 more extensive than that of any other man, declares it as his opinion that the 

 more frequently a tree ia reproduced contimiously from seed, the more feeble 

 and short-lived is the seedling produced. 



Still more, we all know that certain peculiarities of constitution or habit 

 can be propagated by grafting, by slips, and even by seeds. Thus the variegated 

 foliage, which is a disease of some sort, is propngated forever by budding, and 

 the disposition to mildew of some kinds of peaches is continued almost always 

 in the seedlings. That the peach-tree is peculiarly constant in any constitu- 

 tional variation, the Nectarine is a well-known proof. That fruit tree is only 

 an accidental variety of the peach, and yet it is continually reproduced with a 

 smooth skin from seed. 



Is it not evident, from these premises, that tlie constant sowing of the seeds 

 of an enfechled stoch of j^caclies ivould naturally produce a sickly and diseased 

 race of trees ? The seedlings will at first often appear healthy, when the parent 

 had been only partially diseased, but the malady will sooner or later show 

 itself, and especially when the tree is allowed to produce an over crop. 



That poor soil and over-bearing will produce great debility in any fruit tree, 

 is too evident to need much illustration. Even the apple, that hardiest orchard 

 tree, requires a whole year to recover from the exhaustion of its powers caused 

 by a full crop. The great natural luxuriance of the peach enables it to lay in 

 new fruit-buds while the branches are still loaded with fruit, and thus, except 

 in strong soil, if left to itself, it is soon enfeebled. 



There are some facts in our every day observation which may be adduced 

 in proof of this theory. In the first place, the varieties of this tree always 

 most subject to this disease are the yellow peaches ; and they, it is well known, 

 also produce the heaviest crops. More than nine-tenths of the victims, when 

 the disease first appeared, were the yellow-fleshed peaches. On the other 

 hand, the white-fleshed kinds (those white and red externally) are much more 

 rarely attacked; in some parts of the country never. They are generally less 

 vigorous, and bear more moderate crops. And it is well worth remarking that 



* Theory of Horticulture. 



6 



