176 STATE HORTICULTURAL SOCIETY. 



when the first symptoms appear. Assuming that the cause of the disease 

 is a contagium which has gained an entrance into the tree through such 

 blossoms as develop into prematurely ripened fruit, then it follows that 

 the disease is first of a local nature, as the appearances indicate; and it 

 would seem that it might be removed, in some cases at least, if the excis- 

 ions were vere very prompt and rigorous. Anyway, this was the theory on 

 which I proceeded. 



The experiments are as follows: 



A. — Orchard of William Brothers, Dover, Delaware.— Trees set three and a half 

 years; both of them cases of 1887; selected out of twenty-seven as being most suitable 

 for this experiment. The limbs which bore affected branches were cut away close to 

 the body of the tree, and the stumps were painted. 



(1) September 16, 1887. Variety, Beers' Smock. This tree seemed to be healthy, 

 except parts of one large limb. This limb showed slight beginnings of diseased sprouts, 

 and bore one peach, which was ripe, red-spotted on the skin and red-spotted and streaked 

 in the flesh. The limb was removed. 



Result. — August 16, 1888. The tree is full of peaches, and three fourths of them are 

 now ripe and red-spotted. The proper time of ripening of this variety in this locality 

 is about the middle of September. Only two small limbs bear green, healthy fruit. 

 The foliage of the affected limbs is yellowish, and they bear a few small diseased shoots. 



(2) September 16, 1887. Variety not recorded. This tree bore no fruit, but diseased 

 sprouts have developed on one limb, and to a greater extend than on No. 1. This limb 

 was cut away. The rest of the three seemed to be healthy. 



Result.— August 16, 1888. The tree is badly diseased. It now bears premature fruit 

 on all parts. Also on all of the main limbs there are many diseased shoots, and some 

 of them are large. 



All of the diseased trees, except those two, were removed in 1887. 



B. — Orchard of James W. Green, Magnolia, Delaware. — Trees set five and a half 

 years; all cases of 1887; selected out of several hundred as being freest from symptoms 

 of yellows. In all of these trees the disease appeared to be localized on one or more of 

 the several main limbs. In fact, I was at great pains to select trees which showed the 

 premature peaches and feeble shoots only upon a few limbs. Many otherwise promising 

 trees were rejected because of slight symptoms upon the base of the main limbs. In 

 several cases there were yet no diseased sprouts. In none were there very many. In 

 some of the trees healthy shoots of that summer had grown out between the diseased 

 parts and the point of amputation. The limbs were sawed off smoothly and the stumps 

 were painted. Whenever a small diseased branch joined a larger healthy limb I 

 severed both, cutting below next to the body of the tree in order to be more certain of 

 success. In most cases, from one third to one hal f of the tree was removed. All that 

 was left, and much of what was cut away, appeared to be perfeotly healthy. In some 

 trees the symptoms of disease were more pronounced than in others, but the final results 

 were the same. 



(1) September 15, 1887. Variety, Beers' Smock. Two main limbs were removed; five 

 of the same size were left. 



Result. — August 17, 1888. The tree now bears premature fruit on every main limb. 

 It also bears diseased shoots. Some of the smaller branches bear a few sound peaches. 



(2) September 15, 1887. Variety, Beers' Smock. Three limbs were removed; three 

 were left. 



Result. August 17, 1888. The tree bears many peaches, most of which are pre- 

 mature. Upon two of the three main limbs, some branches only still bear green, healthy 

 peaches. The trunk and limbs also bear diseased shoots. 



(3) September 1, 1887. Variety, Beers' Smock. One small limb, one and a half inches 

 in diameter at the base, was removed; four large limbs with many branches were left. 



Result. — August 17, 1888. The tree is now badly diseased in every limb, and bears 

 almost nothing but premature fruit, i. e., there are not over forthy green peaches on the 

 entire tree. Diseased shoots have also grown from every limb and from the trunk near 

 the earth. 



(4) September 15, 1887. Variety, Beers' Smock. A smaller tree than No. 3. One 

 limb was removed, two were left. 



Result. — August 17, 1888. One of the two main limbs bears green, healthy peaches; 

 the other bears mixed fruit. That on two branches is premature; that on three others 

 is healthy. There are no diseased shoots. 



(5) September 15, 1887. Variety, Beers' Smock. A lar^e, fine tree. One limb was 

 removed, four limbs were left, 



