CLOVER LEAF SPOT 145 



under surface also. At a later stage a small brown pustule 

 appears in the centre of each spot, and most frequently 

 on the upper surface of the leaf, looking much like the 

 brown pustule of teleutospores belonging to some Piiccifiia ; 

 but when examined under the microscope, the pustule is 

 seen to consist of numerous asci, each containing eight 

 colourless, elliptical spores. These ascospores escape 

 when mature, and are scattered by wind, inoculating those 

 leaves on which they happen to alight. 



The disease when present usually assumes the character 

 of an epidemic, due to the rapid and abundant diffusion of 

 spores, and consequently considerably reduces the forage 

 by preventing growth owing to the destruction of the 

 leaves. 



Preventive Means. — The disease readily survives the 

 winter on stray plants in the field or on wild clovers, and 

 unless precautions are taken is likely to infect the crop 

 the following season. Burning over the field in late 

 autumn or early spring, if there is not sufficient dry 

 material present, straw or other refuse might be spread 

 over the field and burned. 



Frequent cutting of the crop prevents the disease from 

 doing serious damage. 



Combs, Iowa State Coll. of Agric, No. 9, figs. (1898). 



LARCH CANKER 



{Dasyscypha calyd?ia, Fuckel. 

 = Peziza willkonwiii^ Hartig.) 



This beautiful little fungus is very destructive to the 

 larch (Z. eiiropea), especially when crowded and growing 



K 



