PEACH YELLOWS AND PEACH ROSETTE. 187 



I have studied this disease seedling orchards are infrequent, but from 

 what data I have been able to gather I should say that seedling trees 

 derived from budded fruit are equally subject. 



On the Delaware and Chesapeake peninsula the belief is also pretty 

 general that budded trees imported into diseased districts from healthy 

 localities are as much subject to yellows as those grown at home, or at 

 least do not escape the disease. On the other hand, I have been told by 

 growers that they have had little trouble from yellows since they have 

 formed the practice of selecting their own buds and stocks. The well- 

 known habit of certain nurserymen to buy trees wherever they can, and 

 sell them again as their own stock, obscures what would otherwise be a 

 somewhat simple problem. In many cases in studying orchards it has 

 been difficult to determine the origin of the stocks, and impossible to learn 

 anything about the location or character of the trees from which the buds 

 were taken. Because nursery stock was grown in a locality free from yel- 

 lows it by no means follows that the buds came from the same locality. 

 Buds are often procured directly from a distance, or are taken from young 

 trees recently introduced into a neighborhood. In case of new varieties, 

 I have several times known trees to be propagated from young trees 

 recently introduced from localities where this disease is very prevalent. 

 In buying trees much depends upon the integrity of the nurseryman, 

 which is often an unknown factor and sometimes a negative quantity. 



The fact that growers in the diseased districts have bought trees from a 

 good many nurserymen with pretty much the same results is tolerably 

 strong evidence, although not entirely conclusive. 



A knowledge of these facts led me to plan an experiment in which I 

 should know in advance the character of the stocks and the buds, and be 

 able to watch the behavior of the parent trees as well as the progeny so 

 long as might be necessary. 



(2) Experiment 1. — The trees for this series of inoculations were 1,000 

 Mariana plums rooted by J. W. Kerr, at Denton, Maryland, in the spring 

 of 1888 from cuttings made in his own orchards. They were divided into 

 five lots and inoculated in August, 1888, with buds taken from five healthy 

 peach trees also in Mr. Kerr's own orchards. These five trees were care- 

 fully 'located and have been under observation ever since. I examined 

 them particularly May 23, 1890, making the following memoranda: 



The character of the trees from which came the buds used in working the peach on 

 plum roots is as follows, all of the buds of one variety having been taken from one tree: 



(1) Oldmixon. — Exact origin unknown; set out by T. A. Smith of Denton; age, 38 

 years; entirely free from yellows; a foliage of a healthy green. 



(2) Crawford's Early. — Budded by Mr. Kerr from a bearing tree in Caroline county; 

 set in 1874; entirely free from yellows; foliage vigorous. 



(3) Mountain Rose. — Budded by Mr. Kerr from a bearing tree in Caroline county; 

 set in 1876; entirely free from yellows; foliage vigorous. 



(4) Crawford's Late. — Budded by Mr. Kerr from a bearing tree in Caroline county; 

 set in 1876; entirely free from yellows; foliage vigorous. 



(5) Beers' Smock. — Budded by Mr. Kerr from a bearing tree in Caroline county; 

 set in 1876; entirely free from yellows; foliage vigorous. 



These trees are old and broken, but they are not diseased. 



The entire orchard was examined at that time. It contains about five 

 hundred trees. They remind me of trees in the old orchards at Seaford, 

 Delaware. Like them they suffered severely during the winter of 1881-82,* 



* The severity of that winter killed the dormant peach bnds in Caroline county. Maryland,— a thing 

 never known before or since. It also injured the wood of many limbs. The same injuries occured at 

 Seaford, Delaware. However, at neither place did yellows supervene, and the belief that this disease is 

 due to autumn frosts or severe winters is wholly untenable. There is not one fact offered in support of 

 this view which may not be explained equally well in other ways. 



