322 STATE HORTICULTURAL SOCIETY. 



In a general way, the descriptions that have been given of the other 

 powdery mildews will apply to this one. It appears early in the sea- 

 son upon the young leaves and tender shoots, and has at first a cob- 

 webby appearance, but, when the spores have formed, it has a white, pow- 

 dery look and later on becomes brownish, owing to the presence of the 

 dark-colored, winter spore coverings. The growth is checked and in severe 

 cases the leaves drop ofP, leaving the bare stems. The action of the fungus 

 upon the fruit is to check the growth of the portion attacked, and cause it 

 to become misshapen. In many localities it has been useless to attempt the 

 cultivation of the European varieties on account of this disease. Attempts 

 have been made to grow them under conditions similar to those to which 

 they are accustomed, by planting in deep, rich, moist soil, and mulching 

 the plants. Others find them fairly successful on the north side of a 

 fence or building. The use of sulphur was also tried and seemed to have 

 a good effect, but within the past five years a better remedy has been found 

 in liver of sulphur (sulphide of potassium). While Bordeaux mixture 

 is even more effectual and is preferable on account of its sticking quali- 

 ties for use early in the spring, it is better to use the potassium sulphide 

 or weak copper sulphate solution after the fruit is half grown, as it will not 

 spot the fruit. To keep the European sorts free from mildew, it is well to 

 spray the plants once in from two to four weeks from the time the leaves 

 come out until the middle of August. The longer time will answer if 

 insects or mildew do not appear, but, whenever it manifests its presence, 

 the fungicide should be applied at once, together with Paris green or 

 pyrethrum according to the season, if worms trouble. 



While mildew is the most troublesome of the diseases of the gooseberry, 

 it is sometimes seriously injured by several "leaf-spot" diseases, which 

 will be described as affecting the currant, and the rust (^cidium 

 Orossularicp, Schum. ). As a rule, the treatment recommended for mildew 

 will sufiice for the others. 



DISEASES OF THE CURRANT. 



Frequently the foliage drops from currant plants during the summer, 

 owing to the presence of fungi, of which* the most comman are the so- 

 called spot diseases (Septoria rihis and Cercospora angulata, Winter). 



These differ but slightly from the other spot diseases and cause small, 

 brown spots to show on the leaves during June and July, and, the tissues 

 being destroyed, the affected portion drops out. In several ways the spots 

 caused by these diseases bear some resemblance to the strawberry leaf- 

 blight and may in time be referred to the same genus. 



In sections where this disease is troublesome, the spraying of the plants 

 should not be neglected. By the use of two or three applications the 

 leaves can be retained upon the plants throughout the season. 



