42 



THE MONTHLY BULLETIN. 



Peach Leaf Curl. 



Leaf curl is another fungous enemy of the peach. It has a wide dis- 

 tribution in California. 



Duggar* gives the symptoms of leaf curl attack as follows : 



' ' The idea generally prevails that the leaf curl occurs only upon 

 leaves and young branches, but the flowers and young fruit are lilie- 

 wise subject to attack. Since in the latter case the deformations 

 are less conspicuous, and dropping of the parts affected is more 

 prompt, it has often escaped attention. Leaves of the peach 



Fig. 24. — Peach tree showing the effecLs of a bad attack of curl leaf. (After 

 Weeks, Mo. Bui. Cal. Hort. Comm., Vol. I, No. S.) 



affected by this fungus may be detected as soon as the leaf Ijuds 

 have become slightly unfolded. The coloring of the young leaves 

 is somewhat heightened, and as they unfold a curling and arching 

 of the blades becomes i:>rominent. The distortion may be confined 

 to a small area on one leaf as one extreme, or it may occur on all 

 leaves and petioles, as well as on the young stem which bears these. 

 As the leaves mature the green or reddish color is lost and the 

 hj^pertrophied areas l)ecome pale in color. Further changes in the 

 external appearance have been noted in a gray or mealy appear- 

 ance of the surface, which occurs as a result of the production of 

 the fimgus superficially. Later the affected leaves turn brown and 

 are finally defoliated. When defoliation is extensive the fruit crop 



* Fungous diseases of plants. 



