43 



DISEASES OF CULTIVATED PLANTS 



Die back of willow shoots {Diplodina sa/ichia, Cke. and 

 Mass.) attacks the tips of willow shoots and causes them to 

 die back for a distance of six inches or more. The shoots 

 become brown and the scales of the buds are indurated. 

 The fungus bursts through the bark at numerous points, form- 



ed 



. 133. Ascochytaaspidistrae. 1 , <>n portion ofa 



leaf of. / tpidistra lurida ; 2, perithecia of the fungus 



bursting through the epidermis of the leaf, mag; 



3, section ofa perithecium, mag ; 4, spores, highly 



nag. 



ing minute cavities with a raised border. The conidia are 

 very numerous, hyaline, elliptic-oblong, i-septate, smooth, 

 18-24x5-7 /'. 



Diseased portions should be removed and burned. 



ASCOCHYTA (Lib.) 



Perithecia minute, generally immersed in the substance of 

 bleached spots on leaves or twigs, with a terminal pore; 

 I -septate, hyaline. 



