EXPERIMENT STATION BULLETINS. 279 



REMEDIES. 



The efficiency of sulphide of potassium ("liver of sulphur") has been 

 questioned by growers with whom we have spoken ; but Professor Scribner 

 recommends a solution of it in the proportions of one ounce to eight gallons 

 of water. Apply this by spraying once per week, from the beginning of 

 the growing season till the berries begin to ripen. He also suggests the 

 use of the copper solutions, and recommends, "three ounces of carbonate of 

 copper disolved in one quart of water, which should be diluted to twenty 

 gallons." 



The copper solutions have the advantage of adhering strongly to the 

 foliage, so that rain does not wash them off readily. It would be wise to 

 apply such solutions after the crop is gathered, at intervals of two weeks 

 until September. 



The purpose of the above is to prevent the germination of conidia and 

 the infection of the new leaves. Should these leaves become more or less 

 infected in spite of the treatment suggested, and should the plants other- 

 wise appear in fair condition, lightly raking up the dry mulch in the spring- 

 is advised, and burning it together with the leaves of the strawberry. The 

 treatment seems harsh, but if there is not too much of the mulch the 

 plants will send up even a finer growth, and the source of infection is 

 almost wholly destroyed. 



SUMMARY. 



1. Sphaerella Fragarice, Saccardo, passes the winter in this region in at 

 least three different conditions: 1, as mycelium in the leaves near the spots; 

 2, in the so-called sclerofia; 3, as ascospores in perithecia. 



2. Reproduction is provided for through conidia and ascospores; the 

 former ephemeral, the latter long-lived. 



3. The ascospores germinate within the ascus and perithecium, and 

 their micelium, growing through the mouth of the perithecium, rapidly 

 prodiices numerous conidia capable of infecting the strawberry. There 

 seems to be proof that no infections take place directly from the germinat- 

 ing ascospore. 



4. The only mode now known of infecting the new leaves of the host-plant, 

 is through the conidia, which grows from the mycelium about the white spots, 

 from that of the sclerotia, and from that produced by the ascospore. Con- 

 sequently the conidia, or the spotted leaves themselves, must be destroy- 

 ed in order to insure immunity against the disease. 



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

 leaf -stocks 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 cultivation, two 

 modes of treatment will be found to repay the fruitgrower. First, if the 

 season opens unfavorably, the regular use of the fungicides recommended; 

 second, if the fungus persists till autumn, destruction, in the following 

 spring, of all the old leaves by burning over. 



W. R. Dudley. 



