280 STATE HORTICULTURAL SOCIETY. 



ANOTHER DISEASE OF THE STRAWBERRY. 



Ascochyta Fragarice. — Sacc. 



Ill June, 1890, Mr. Cliarles M. Bootli of Rochester, forwarded leaves of 

 the Manchester strawberry badly diseased. He says 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 the leaves and the one occasioning the disease, was 

 Ascochyifi Fragaricv, Saccardo, the spores of which are shown in the 

 accompanying figure. Certain leaves were from one third to one half dis- 

 colored 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 reddish tint. This discoloration is due to precisely the 

 same causes as operate in producing a similar appearance in the leaf -blight 

 described in the preceding pages. The riiijceliu))i grows among the cells 

 in the interior of the strawberry leaf, disorganizes and discolors their con- 

 tents and absorbes their juices. Partly sunk in the diseased tissue of the 

 leaves and arising from the mycelium in the interior of these specimens, 

 appeared small blackish fiuiting organs, i\ie pcriiheci((, about ^ to yV of a 

 millimeter ( ^^ ^ to g ^ ^^ of an inch ) in diameter. The spores arising from 

 the bottom of the perithecia were fusiform or cylindrical, two-celled 

 slightly constricted at the middle, either straight or usually with one or 

 both cells curved, .014 to .027 mm. long by .004 to .0056 mm. wide. The 

 spores are larger than those in the saccardoan species, but without express- 

 ing here a final opinion, there are reasons for thinking that the forms of 

 Ascochyta on the strawberry leaves, described by Saccardo, by Peck and in 

 this note, belong to one species, A. Fragcirkv, Sacc. 



A considerable number of artificial cultures of the spores were made, but 

 they did not germinate readil}', and at that time no conidia were formed on 

 the mycelium. We have not found it about Ithaca, and would solicit more 

 material another season from correspondents, if it reappears on the straw- 

 berry. Hitherto Ascochyta has never been reported as destructive of this 

 host, so far as we are aware. 



As this is endophyllous, {i. e. lives within the leaf), it is necessary to spray 

 the leaves before the time of plant's blooming, with a fungicide in order to 

 prevent any possible entrance of a germinating spore into the tissues. The 

 spores are killed by the Bordeaux mixture; but this mixture may be too 

 strong for the young leaves, and the weaker Bordeaux mixture is advised. 

 As this fungus is so similar to the leaf-blight in its habits, we urge 

 those troubled with the disease occasioned by the Ascochyta to experiment 

 also with the remedies suggested for the leaf-blight and to report the 

 results. 



W. R. Dudley. 



