DIVISION OF GARDENS AND GROUNDS. 41 



Jittle known on the Delaware peninsula : what little we have seen of it.'* 

 he says, "is supposed to have been introduced from Xew Jersey.'' 



Butter, in his book on peach culture, remarks that " the-ycllows ap- 

 pear more particularly after unusually wet seasons." 



In the earliest writin<:?s on this subject the disease is referred to soil 

 exhaustion, and the remedy suggested is to apply fertilizers, but we have 

 ample proof that it is found on rich soils as well as on poor soils ; neitlicr 

 is it found on all poor soils, because it can be shown that, in many locali- 

 ties where it is seldom if ever found, such as on the Delaware and Vir- 

 ginia i^eninsulas, the soil is quite as poor and impoverished as it is in any 

 part of JTew Jersey where the disease is common. We are not prepared 

 to admit that impoverished soil and neglected culture is the cause of 

 the yellows in New Jersey and Michigan, and the converse of these 

 factors, the reason why it is seldom found in the States of Virginia and 

 x^orth Carolina. 



We have for more than a quarter of a century been strongly impressed 

 with the opinion that the virulent disease known as yellows has for its 

 origin the injury which follows the action of frost upon unripeued shoots 

 in the fall. 



Our attention was first directed to this as a cause from the following 

 circumstances : In the fall of 1851 we had several plants of the ever- 

 green or Japan euonymus growing in a rich border, in a somewhat 

 sheltered position. The weather, during August in particular, had been 

 dry and warm. This condition of weather was followed by an abundance 

 of rain and a mild temperature, which continued late and until vegeta- 

 tion was suddenly checked by a severe frost. The euonymus plants 

 started to grow luxuriously after the September rains, making strong 

 succulent shoots, the points of which were shriveled and blackened by 

 the first frosty night, and most of the leaves below the blackened parts 

 dropped from the stems. It was observed that these injured plants 

 were tardy in commencing growth in spring, and the only buds that 

 started were those at least one foot below the extreme points which still 

 remained black and shriveled. This blackened portion was removed 

 and no further special notice was given the plants that season. But 

 after growing weather commenced in the following spring my attention 

 was attracted to the quantity of young slender sprays which were grow- 

 ing from the stems to within 10 to 12 inches from the surface of the 

 ground. These stems were clothed with small yellow leaves, remark- 

 ably similar to those which indicate yellows on the peach. 



When cutting down below these yellow shoots in the fall it was ob- 

 served that the interior of the branches was discolored, and had an ap- 

 pearance similar to what may be seen in a blighted pear branch ; by 

 l^runing still closer this discolored wood disappeared, and afterwards 

 strong healthy shoots were i^roduced showing no signs whatever of 

 disease. 



This phenomenon appeared to be so similar to the external evidence 

 of yellows in peach trees that it led to further observations in that 

 direction, all which have helped to confirm the opinion that peach trees 

 which make late soft growths and are caught by severe frosts while in 

 this condition are those in which the yellows will speedily develop. 



So far as known no person has ever met with a case of yellows in 

 peach trees cultivated in glass structures. Of course the number of 

 peach trees cultivated in this way is very small when compared with 

 the peach orchards of this country, but there have been many thou 

 sands of trees grown in this manner, and the trees have been procured 



