April, '10] X()i:t(,)X: i-eacii diseases 235 



and various fungi, such as Cercospora circumcissa, C. persicce, Phyl- 

 losticta persicce (in Maryland last summer), Macrosporium commune 

 (Michigan), Bacterium pruni, etc., have been noted as causing these 

 troubles. 



Chlorosis 



Aside from the yellowness of foliage mentioned already under 

 yellows, etc., a yellow foliage condition is well known in Europe 

 under the name of Chlorosis. 



Powell (Delaware 1897) reports a case of yellowish willow-like 

 shoots, from newly budded stock, identified by experts as yellows, 

 but which disappeared as the trees grew older. He attributes it to 

 influence of the bud and weather conditions causing late growth. 

 These yellows-like shoots are often seen in nurseries and when older 

 trees have been severely pruned, or when growth has been checked 

 by grafting, bending, or constricting a branch. 



Following the excessive wet spring of 1909 in Kansas, I noticed 

 that the foliage at the ends of many peach branches as well as on 

 other species was almost white. Selby attributes to wet soil, a varie- 

 gated foliage with yellow along the veins, seen in Ohio; and Stewart 

 and Blodgett report a condition with watery edge to the leaves, later 

 becoming yellow and passing into tip burn ; cause unknown. 



Leaf Roll, Wilt, Leaf and Fruit Drop 



These conditions may be due to various troubles, girdling b}' borers, 

 wire, winter injury, dry or stony soil (see Johnson's frenching disease, 

 Maryland 1896) or even to wet soil, in addition to such diseases as 

 yellows and little peach. Wilting due to unknown causes has been 

 mentioned by several writers. 



A bud dropping disease (cause unknown) is reported from South 

 Africa and similar troubles in English greenhouses are attributed to 

 improper ventilation. 



The June drop has been rather a mysteiy but probably is as Waugli 

 says due to combined action of nonpoUination, curculio and the strug- 

 gle for existence. 



Prematuring of Fruit 



This may be caused by yellows (in which case it is distinguished 

 by the peculiar red spots) by borers, or by girdling in other ways. 



