A Study of Meadow-Crop Diseases in New York 63 



deaux mixture." On the other hand this seems unlikely since the mycelium 

 of the fungus is almost strictly endophytic, and hence out of reach of 

 external toxic agents. 



Killian found that if he planted crimson clover in September rather 

 than in July, as is the usual practice in France, the crop derives a certain 

 amount of protection against the pathogene because the more vigorous 

 early planted crop is more susceptible. 



Several attempts to determine the value of fungicidal mixtures as 

 protectants were futile because of poor germination or none at all in the 

 checks. Bordeaux mixture, as suggested by Cooke, or its equivalent, 

 copper-lime dust, might have some effect as a protectant. 



PSEUDOPLEA LEAF SPOT 



Suscepts 



In New York alsike, red, and white clovers, yellow trefoil, and alfalfa 

 are affected by Pseudoplea leaf spot. Yellow trefoil is here reported 

 apparently for the first time as a suscept. Medicago hispida, M. maculata 

 (Miles, 1925:683), and M. falcata (Saccardo, 1902:554) are listed also as 

 suscepts. Alsike and white clover are the most likely to be found diseased 

 in this State. 



The disease 



This malady occurs widely on the three clovers in New York. It has 

 been collected in Schoharie and Tompkins Counties on alfalfa and in the 

 latter county on yellow trefoil as well. According to the records in the 

 Plant Disease Reporter and of Jones (1916:299), it occurs in Georgia, 

 Illinois, Kansas, Minnesota, Missouri, Wisconsin, Alabama, Virginia, Iowa, 

 Indiana, and South Dakota. Doubtless it occurs in other States as well. 

 The European countries from which it has been reported are Denmark 

 (Rostrup, 1899), Wales (Stapledon and others, 1922), Italy (Pollacci, 

 1902), and Austria (Bubak, 1909). Puttemans (1905) collected it in 

 Brazil. 



Symptomatology 



The first symptom of the disease on any of its suscepts is the occurrence 

 of hundreds of minute black, somewhat sunken flecks on both surfaces of 

 the leaves and on the petioles, giving them the appearance of having been 

 well peppered (figure 15). Stands of white clover along roadsides actually 

 are darkened at times by the millons of spots on the leaf blades. Attention 

 is called especially to the lesions on the petioles. 



On white clover the spots enlarge slowly but rarely attain a diameter 

 greater than from 1 to 2 millimeters, at which time the center is gray with 

 a narrow dark reddish brown zone about the margin. On alfalfa the spots 



