PESTS OF ORCHARD AND FRUIT GARDEN. 



37 



The receptacles are always few and scattered, being small and globose 

 as usual, and attached to the mycelium by a small bundle of fibres from 

 the base. The circle of appendages which surround the conceptacle 

 consists of from ten to fifteen colourless radiating slender arms, which 

 are forked near the tips, each branch being again forked, and the 

 extremities of all the branchlets split into two teeth, which are pointed, 

 and not thickened as in some other species. 



The contents of the mature conceptacles are from four to eight ovate 

 sacs, or asci, each of which encloses four or five hyaline sporidia, so 

 that each conceptacle may contain from sixteen to forty spores. 



The mycelium of these mildews does not in the first instance establish 

 itself within the substance of the leaves, and never enters to any appre- 

 ciable extent. Hence it is an epiphyte, and has only to be destroyed to 

 restore the vigour of the affected plants. It is in this class of diseases 

 that the application of sulphur is likely to prove most beneficial. 



Sacc. Syll. i. 40 ; Cooke M. F. 240 ; Cooke Hdbk. No. 1922 ; Mass. 

 PI. Dis. 95, fig. 15 ; Jouni, R.H.S. xxv. (1900), p. 145. 



American Gooseberry Mildew. 

 Splicer otheca mors-uvce (Schw.). 



This disease has been widely and well known in the United States 

 for scores of years, but only recently has visited Ireland, which entitles it 

 to notice here. As a proof of its virulence, one American writer states • 

 " The mildew of the Gooseberry is the most serious obstacle to the 

 successful culture of the foreign Gooseberry in the United States." 



It first makes its appearance on the young half -grown leaves and the 

 unfolding bud of the shoot. Then it has a cobwebby appearance, which 

 soon becomes white and powdery. Soon after this patches may be found 

 on the berries, usually on one side more than on the other. Later on 

 the leaves, petioles, and young stems turn a rusty brown colour, and 

 become thickly coated with the fungus. The berries at the same time 

 are covered with brown patches of mycelium, which may be readily 

 peeled off. 



The conceptacles are developed upon the mycelium in this species, as 

 well as on the Hop mildew, and the sporidia (15 ^ long) are in like 

 manner developed within the asci. 



Experiments made have shown that as a fungicide in this instance 

 potassium sulphide was far more effective than Bordeaux mixture, lysol, or 

 formalin, using one ounce of potassium sulphide to two gallons of water. 

 Repeat the application every ten days till the fruit is nearly mature. 



Sacc. Syll. i. No. 12 ; Greuillea, iv. p. 158 ; Journ. R.H.S. xxv. 

 (1890), p. 140, fig. 37 ; xxvii. (1902), p. 596, fig. 166 ; Mass. PI. Dis. 

 97. 362. 



Gooseberry Polypore. 



Fomes ribis (Fries). 



This hard woody Polyporus may often be found growing at the base 

 of the stems of old Gooseberry and Currant bushes, and has now the 

 credit of being a true parasite. 



