DISEASES OF CULTIVATED PLANTS 491 



the proper time, one person can examine and pick from 300 to 

 400 plants per hour. After this, diseased buds which are over- 

 looked may be removed while cultivating the plants. It ds very 

 doubtful if the fungus will mature on these buds after removal, 

 but as a precaution they should be destroyed. (Del. E. S. B. 93.) 



GOOSEBERRY. 



Leaf -Spot. The gooseberry leaves are attacked by the same 

 leaf-spot fungus recorded upon the currant (Septoria ribis Desm.), 

 although the defoliation may be even more severe than on the 

 currant. In spraying experiments at this Station, conducted by 

 the Horticulturist, it has been found that the gooseberry leaf-spot 

 is more easily prevented than the currant leaf-spot. Indeed no 

 fungus disease upon which we have experimented is more easily 

 prevented when the fungicide is applied at the proper time. (See 

 Spray Calendar). Often the leaves from gooseberry plants have 

 all dropped before maturity of fruit, and in hot weather all the 

 fruit has been lost on the unsprayed, check plants, while the sprayed 

 plants gave a fine yield of satisfactory fruit. 



Powdery Mildew. This is a destructive fungus disease espe- 

 cially common upon English varieties such as Industry, Crown Bob, 

 etc., it has been destructive also upon the Houghton. As already 

 stated this mildew attacks currants. From the nature of this fungus 

 the first spraying with Bordeaux mixture should be made early in 

 the season. ((See Bulletin 79). Subsequent applications may be 

 either of Bordeaux mixture or potassium sulfid. After fruit is half 

 grown the latter fungicide is to be preferred since it is more easily re- 

 moved from the fruit. (Ohio E. -S. B. 214.) 



Raspberry Cane Blight. Both red and black raspberries are at- 

 tacked, but on red varieties the symptoms are somewhat different 

 from those on black ones. The principal damage is done to fruiting 

 canes although new canes are attacked and occasionally killed during 

 the first season of their growth. The foliage on affected canes wilts 

 suddenly and becomes dry. The whole cane may be involved or only 

 a portion of it. Often a single branch is killed while the remainder 

 of the cane continues alive and apparently normal. In the majority 

 of cases only a part of the cane dies. With black caps the disease 

 frequently starts in the old stub left in pruning. From this point it 

 gradually works downward killing first the uppermost branch, then 

 the next lower one and so on until by the close of the berry harvest 

 one-half or more of the cane may be dead. On black caps, the dis- 

 ease also shows a tendency to work down one side of the cane killing 

 the bark and discoloring the wood on that side while on the other 

 side the bark remains green. This may occasionally happen with 

 the red varieties, but as a rule they are attacked at some particular 

 point on the cane. Here the bark is dead and the wood brown. For 

 some time the injury extends only part way around the cane and as 

 long as there is a strip of green bark left connecting the parts above 

 the point of attack with those below all goes well ; but when the in- 

 jury at length completely encircles the cane the leaves on the portion 



