DRUPACEOUS FRUITS 133 



dant as to almost completely ruin the crop, by attacking 

 the leaf, fruit, and twig. When on the fruit, it appears first 

 while the peach is small, causing irregular, grayish, moldy 

 blotches. As these enlarge, cracks often develop. 



The winter cleansing sprays recommended for the peach 

 curl are effective in killing wintering spores, and thus largely 

 diminish the injury from this pest. 



Powdery mildew, sphaerothecose (Sphcerotheca pannosa 

 (Wallr.) Lev.). — This powdery mildew, in general appear- 

 ance like podosphseria, sometimes interferes with the growth 

 of leaves and young twigs and stunts the trees. For treat- 

 ment, see podosphaeriose. 



Frosty mildew {Cerposporella Persica Sacc). — In damp, 

 shaded localities, especially on trees of dense foliage, a 

 disease occurs in the form of pale yellowish leaf spots. 

 These show, on the underside, a delicate frostlike appear- 

 ance, due to the growth of white spore-bearing hyphse. 

 It is not usually serious, though widespread, and the 

 treatments recommended for the other diseases will suf- 

 fice to hold this disease in check also. 



Texas root rot. See cotton. 



Shot hole, cercosporose (Cercospora circumscissa Sacc). 

 • — This is very widespread, producing spots, or, when the 

 diseased tissue falls out, oval holes, in the leaves. It also 

 infects small branches. The chief injury lies in destruction 

 of leaf tissue and of valuable shoots. 



The dormant spraying recommended for the curl is useful 

 here. 



Shot hole, phyllostictose (Phyllosticta circumscissa Cke.). 

 ■ — This is similar in appearance and treatment to cercospo- 

 rellose. 



