FRUIT NOTES - July, 1938 



W. H. Thies 

 Extension Horticulturist 



The "X Disease" in Massachusetts 



A disease of peach trees which has been observed in Connecticut for 

 a number of years is now definitely known to be present in Massachusetts. A 

 visit vms made to four peach orchards on August 2 with E. M. Stoddard and his 

 associates Odell and Fitzpatrick of the Connecticut Agricultural Experiment 

 Station, and J. S. Bailey of the State College staff. Theee orchards are 

 located in Hampden, Worcester and Middlesex Counties. In three of the four 

 orchards "sick" trees were found to be affected with tho so-called "X Dis- 

 ease." The fourth orchard showed partial defoliation due to Bacterial Leaf 

 Spot, a fairly common ailmtsnt in Massachusetts. 



According to investigators, the "X Disease" is alv/ays associated 

 v/ith diseased choke cherries, a plant of very common occurrence in New Eng- 

 land. In the choke cherry the disease manifests itself in foliage of abnormal 

 color, in some cases a brilliant autumn red with tufts of greenish leaves at 

 the tips of tha branches. ¥Jherev6r such plants are found growing adjacent 

 to a peach orchai'd there is reason to suspect infected peach trees. This was 

 the case in each of the three orchards mentioned above. A study of condi- 

 tions in the State College orchard in Amherst reveals a similar situation. 

 Certain peach trees shov/ unmistakable symptoms of the "X Disease." 



Briefly, the above disease is characterized by abnormally coloJ'.ed 

 areas in some of the leaves which later drop out leaving a ragged appearance. 

 Such leaves often curl somov/hat tov/ard the mid-rib and later fall from the 

 tree. It is not uncommon for a tree to show only an occasional branch with 

 these symptoms. The removal of such branches, however, does not eliminate 

 th(j difficulty since it tends to spread throughout the tree like other virus 

 diseases, such as Peach Yellows. Thus there appears to be no cure after a 

 tree becomes infected. Elimination of all choke cherry bushes in the vicinity 

 in advance of planting is recoianended. Spraying of th^ choke cherry foliage 

 with one of the recorai.iended weed killers is recoaraended. Incidentally, the 

 "X Disease" does not kill the peach tree outright. In fact, a disettsed tree 

 will live for years, and loaf out each spring in a normal manner. But few 

 fruits will develop on diseased branches and those which do develop will be 

 of poor quality. It appears now that many of the peach trees in Massachu- 

 setts which have heretofore appeared abnorual for reasons attributed to soil. 

 Peach Yellows, etc., have been affected by this new disease now being studied 

 in Connecticut. V/e suggest that growers be on the lookout for abnormal poach 

 trees and for diseased choke cherries. The further sprt.ad of "X Disease" and 

 tho infection of now plantings may be prevented by taking a few precautions. 



Cold Storage Facilities 



Perhaps it will interest readers of Fruit Notes to know just how 

 much cold storage capacity is available to them and to other Nev/ England 

 and Massachusetts apple growers. 



Issued by the Extension Service, V/illard A. Munson, Director, in further- 

 ance of Acts of May 8 and June 30, 1914. Massachusetts State College, United 

 States Department of Agriculture, and County Extension Services cooperating. 



