778 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



THE AMERICAN GOOSEBERRY MILDEW IN IRELAND. 



By Ernest S. Salmon, F.L.S. 



At p. 139 of vol. xxv. of this Journal I gave the particulars of the out- 

 break, in 1900, at Bally mena, co. Antrim, Ireland, of the American 

 Gooseberry mildew, Splicerotheca mors-uvce (Schwein.), Berk. & Curt. 

 This disease again appeared in the same locality in 1901. I give below 

 the notes supplied to me by the gardener (Mr. J. Nixon, at Whitehall, 

 Ballymena), together with some general observations on the present 

 fungus. 



Mr. Nixon wrote : " The disease this year was even more extensive 

 than last ; and the young wood seems more affected at this time of year 

 (August) than it did last year. I have not heard of any neighbouring 

 gardens being affected as yet. Some varieties of Gooseberries are far 

 more subject to the disease than others. The ' Large Green ' Gooseberry 

 is not affected, while the ' Small Green ' is very much affected, although 

 both berries are smooth. The ' Amber ' is by far the worst of any. Some 

 varieties of ' Red ' seem proof against the fungus, while others are 

 nearly as susceptible as the ' Amber ' ; the ' Smooth Red ' is the worst." 



Magnus, from a jJ'i'iori reasons, has expressed the opinion that the 

 fungus has been introduced into Ireland from America, and has suggested 

 (1) that imported Gooseberries bearing the fungus may have been the 

 source of infection. This, however, cannot have been the case, as the 

 authorities at the Custom House inform me that no importation of 

 Gooseberries into Britain from the United States occurs. I have learned, 

 how^ever, through Mr. F. M. Moore, A.L.S., of the Royal Botanic Gardens, 

 Glasnevin, that two firms of florists in Ireland imported some years ago 

 Gooseberry plants from the United States. It is certainly possible that 

 by this means the fungus may have been brought over from America. 

 On the other hand, however, we must remember that Ireland possesses 

 some indigenous plants found elsewhere only in North America ; also 

 that, as I have already pointed out (2), the fungus known as Sphcerotheca 

 tomcntosa Otth, which is not uncommon on the Continent on several 

 species of Euphorbia , appears to be morphologically indistinguishable 

 from S. mors-uvcB. 



It may be noted here that De Wildeman (3) has lately enumerated 

 S. mors-uvcB among the ErysiphacccB of Belgium. The record runs, 

 " Sine loco (Em. Marchal)." Up to the present I have not been able to 

 obtain any information about this Belgian record. 



It may be well here to draw attention to the serious economic danger 

 with which European fruit-farmers will be confronted if the American 

 Gooseberry mildew is allowed to establish itself in Europe. The practical 

 aspect of the subject is ably dealt w^ith by Beach (4) in Bull. No. 114 of 

 the New York Agric. Exper. Station, where a full and well-illustrated 

 account of the cultivation of Gooseberries in the United States is given. 

 It is here remarked : " The one great hindrance to the cultivation of 



