— I82 — 



3. The ascospores germinate within the ascus and peiithecium, 

 and their mj^celium, growing through the mouth of the perithe- 

 cium, rapidly produces numerous conidia capable of infecting the 

 strawberry. There seems to be proof that no infections take 

 place directly from the germinating ascospore. 



4. The only mode now known of infecting the new leaves of 

 the host-plant, is through the conidia^ which grow from the myce- 

 lium about the white spots, from that of the sclerotia and from 

 that produced b}^ the ascospore. Consequentl}' the conidia, or 

 the spotted leaves themselves, must be destroyed in order to in- 

 sure immunity against the disease. 



5. The mycelium does not descend to the stem or roots through 

 the leaf-stalks and pass the winter there. Therefore destruction 

 of the leaves, in the fall or spring, destroys the fungus. 



6. Aside from care in the selection of soil and in good cultiva- 

 tion, two modes of treatment will be found to repay the fruit- 

 grower. First, if the season opens unfavorably, the regular use 

 of the fungicides recommended ; second, if the fungus persists till 

 autunni, destruction, in the following spring, of all old leaves by 



burning: over. 



W. R. DUDLEY. 



'O 



ANOTHER DISEASE OF THE STRAWBERRY. 



Ascochyta Fragaria. — Sacc. 



In June, 1889, Mr. Charles M. Booth, of Rochester, forwarded 

 leaves of the Manchester strawberry, badly diseased. He sa3^s in 

 a letter : "The leaves were taken from Manchesters set this spring. 

 The other varieties particularly affected are the President Wilder 

 and the Charles Downing, though all kinds show some spots on 

 the leaves. ... I would like to find some cure for it, and, indeed, 

 must do so or give up raising strawberries." 



The only fungus on these le^aves, and the one occasioning the 

 disease, was Ascochyta Fi-agarice, Saccardo, the spores of which 

 are shown in the accompanying figure. Certain leaves were from 

 one-third to one-half discolored and killed by this parasite. Its 

 presence is first manifested in May or June by the appearance of 

 red spots, which enlarge, turn brown, and soon coalesce with 

 neighboring ones, forming a brown patch which often retains the 



