Fungoid Diseases of the Straicberry. 49" 



nished plant bug {Ligus lyneolaris) have been reported as caused by rust. 

 Some varieties seem to withstand its attacks much better than others, but 

 none are entirely free from it. This is perhaps largely a question of loca- 

 tion, for varieties that succeed nicely in some places are often utter failures 

 in others, on account of this disease. With us. for the last few years, the Wil- 

 son has probably suffered more than any other variety in general cultivation. 

 Downing, Cumberland and Captain Jack also rust badly, while, so far, the 

 Crescent has escaped with but little injury. Bidwell is also comparatively 

 free from rust. In many other localities the Wilson is put at the head of the 

 list for hardiness and ability to withstand injury. Mr. J. T. Lovett, of Little 

 Silver, N. J., is of the opinion that varieties having a large share of foreign 

 blood are less liable to rust than those descended from our native stock, and 

 he also observes that some varieties, like Manchester, that succeed well on 

 light, sandy soil, rust badly on heavy, clay land, while others, like Downing 

 and Kentucky, that succeed well on clay, rust badly on sandy soil. 



Mr. J. Decker, of Jefl'erson county, Kentucky, says that light colored 

 berries, such as Downing, Monarch and Cumberland, are more liable to rust 

 than dark colored ones like Wilson and Crescent. 



So far as I know, the only remedy that has been proposed for this disease 

 consists in dusting the plants with lime. This has been practiced for some- 

 years with good success by Hale Brothers, of Connecticut, and by Mr. 

 Rosaman, of Tennessee. We tried it last spring, in a small way, with ap- 

 parently good results, and shall repeat the experiment next season. This 

 remedy is so easily and cheaply applied that I hope it will be tried exten- 

 sively the coming year, and the results reported to this Society. I would 

 advise dusting the plants lightly when the leaves first start in the spring, re- 

 peating every two or three weeks till the fruit is nearly matured. Mulching 

 the ground around the plants is also of considerable use in preventing rust. 

 Strips left unmulched across a field are frequently quite red with it, while 

 the adjoining mulched plants are but little affected. The Southern plan of 

 allowing crab grass to grow and fall down among the plants is of advantage 

 in this respect, for plants growing up through such a mulch are almost al- 

 ways clean and bright. 



The next species in order of importance is Glcjeosporium potentillx [Ouds], 

 which I have called the " black rust." This has perhaps as wide a geograph- 

 ical range as the last, but so far its injuries have attracted but little attention,, 

 or they have been confounded with those caused by the other species. In 

 its first stages it is sometimes difficult to distinguifh between this and the 

 white rust, but instead of developing white spots in the center, the reddis-h 

 blotches show at length a number of very minute black pustules bursting up- 

 through the epidermis of the leaf. Under the microscope these are found 

 to contain great numbers of curiously curved two-celled spores. Unlike 

 those of the white rust, these are formed within the structure of the leaf, and 

 they are finally liberated by the rupturing of the pustule. When badly^ 

 affected the leaves will often turn yellow, and be thickly sprinkled over hy 



