PEACH YELLOWS AMD PEACH ROSETTE. 193 



The disease does not appear to be due to any ordinary fungus, or to 

 insects. In some respects it is quite like peach yellows, but in others it 

 differs very materially. This year additional observations have confirmed 

 the belief that it is a disease distinct from yellows, and. I shall so consider 

 it until proof to the contrary is forthcoming. 



( 1 ) Plants attacked. — As stated elsewhere, rosette attacks many varieties 

 of peach. None appear to be exempt. It occurs in budded fruit and 

 seedlings. The latter do not escape even when growing in fields and 

 thickets without cultivation. This disease is not confined, however, to the 

 peach, but also occurs in plums — budded trees and seedlings, cultivated, 

 uncultivated and wild, and is equally destructive. I have not seen it in 

 varieties of Primus domestica or in the Mariana, but it occurs in the wild 

 Primus Chicasa, in the Cumberland, and Wild Goose, and also in the 

 Japanese varieties known as Kelsey and Botan. Probably the disease is 

 capable of attacking many other sorts, and requires only a suitable 

 opportunity. 



This year in an orchard near Griffin, Georgia, which I know to have 

 been nearly free from disease in 1890, and quite thrifty and well cared for, 

 I counted about forty bad cases of rosette, divided nearly equally between 

 Kelsey and Botan. These trees were five or six years old, and the loss 

 must have been considerable. 



(2) Characteristics of the disease. — As in peach yellows, this disease 

 not infrequently attacks one or two branches only, at first, but in a much 

 larger per cent, of cases, the whole tree is diseased from the start, and the 

 disease runs its course in a much shorter time. Six months is usually 

 sufficient to destroy a tree, and I have known no cases to last more than 

 two seasons. Such a thing as the lingering on of a diseased tree from year 

 to year, as in peach yellows, is not known. I have seen trees completely 

 diseased in June and dead in November, which first showed symptoms in 

 early spring and were in apparently perfect health the preceding autumn. 

 This is the common course of the disease. 



When a tree is attacked in part, the shoot-axes and foliage of the 

 remaining limbs often appear to be perfectly healthy, but these limbs 

 always develop rosettes, and die the following year. Not infrequently 

 I have observed the disease to progress gradually from the affected side to 

 the healthy, i. e., the parts on the healthy side first to be attacked being 

 the bases of the limbs. The bark of trunk and limbs on affected trees 

 presents no peculiar or symptomatic differences. Undoubtedly there are 

 changes in the cambium cylinder corresponding to the shortening of the 

 terminal shoot-axes, but these are not visible externally. 

 The following are some of the most noticeable symptoms: 

 (a) Young shoot-axes. — Commonly the disease first appears in the 

 unfolding shoot-axes, i. e., in early spring when the buds first open. In 

 healthy trees only a small proportion of the winter buds develop into 

 branches, the rest die or remain dormant. In this disease a very large 

 part of the winter buds grow into shoot-axes and also a very considerable 

 number of dormant buds on the older and larger branches. The shoot- 

 axes in healthy trees, especially the terminal ones, generally attain a growth 

 of six to twenty inches and develop ten to twenty vigorous leaves with 

 dormant blossom and foliage buds in their axils. As the season advances 

 such shoots ripen their wood, cast their foliage, and remain quiescent until 

 spring invites the opening of their buds and the renewal of vegetative 

 activity. In diseased trees, the shoot-axes push only one to three inches, 



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