DISEASES OF PLANTS. 149 



Of blackberry diseases observed, tlie nist, leaf spot, and caiie knot were the most 

 destnietive. The rusts of ))lack))erry are usually called the orange rust and the white 

 rust, from the nature of the fungus attacking the i)lant. A report is given of a third 

 whicli is called the yellow fall rust. This disease is due to T/rdo luilllrri. The fini- 

 gus does not ajjpear es{)ecially severe in its attack and there is no cause for alarm at 

 its oi'currence. 



Tlie fruit rot, blat^k rot, witches' Itroonis, and leaf scorch of cherries are reporttnl, 

 and the occurrence of a new fungus on cherry branches is mentioned. This fungus 

 {('ri/ptotipDriinn i-rrdniiiniii ), while occurring rather fretjuently, is probably not 

 parasitic. 



The diseases of currants and goose) )»'rries ol)si>rved were cane l)light, leaf spot, and 

 powdtTV nnldew. 



The vineyards of western New York were found to be remarkably free from disease 

 during the season. The black rot and downy mildew were destructive only in a few 

 localities, and the powdery nuldew and anthrac^nose were exceedingly rare. In 

 several localities green grapes showed russet bands and blotches on their skin, which 

 were attributed to weather conditions, probably a light frost after the fruit had set. 

 On many of the russeted fruits one or more seeds were sometimes exposed, and this 

 is believed to be due to the same cause as that producing the russet spots upon the 

 fruit. 



Of peach diseases the occurrence of leaf curl, yellows, little peach, l)rown spot, 

 and a disease of peach trees in the nursery cellar, are among those noted. The 

 brown spot is attributed to the fungus IL'hnhiihotiponum carpophihun . This fungus 

 begins its attack while the fruit is stall green, but is most conspicuous on the ripe 

 fruit, where it appears in the form of pink spots and cinnamon brown areas. The 

 spots at first are quite small, and in time a number coalesce, forming irregular areas 

 of cinnamon brown color, the pink discoloration almost entirely disappearing. 

 AVhat ai)pears to be the same fungus was found on the branches of the peach tree, 

 and it is believed that the fungus causing the brown spot is not only j)arasitic on the 

 twigs, l)ut occurs sometimes on the leaves and knots of the trees. Whether para- 

 sitic on leaves or not was not determined. The fungus is known al.so to attack the 

 apricot fruit. The disease of peaches rejiorted frcim the nursery cellar was observed 

 in the winter of 1899-1900. The cellar contained about 10,000 peach trees trenched 

 in sand after the usual manner. Some of the trees were wet when put in the cellar, 

 and the sand stuck to the branches. Early in January, it was found that 15 per 

 cent or more of the trees showed dead sections of 1 to 4 in. on the limbs to which 

 there was adhering sand. A fungus was associated with the disease, but failure to 

 produce mature forms made its identity uncertain. 



Among the diseases of pear ol)served are tire blight, leaf scorch, l)ody blight or 

 canker, injury due to winter and drought. 



Of the ])lum diseases, the fruit rot, sun scald, canker, and gum pockets, were the 

 most frequently observed. Associated w^ith the fruit rot on the mummy plum was 

 a fungus which, it is thought, does the twig little or no harm. The species has been 

 identified a.s Ctmiotheclmn nociale. The canker of the plum is similar to that described 

 on the a])ple as due to a species of Cytospora, but the fungus on the 2 different trees 

 seems to be distinct. The same or a similar si)ecies has also been observed on 

 apricot and j)each. Inoculation exjieriments were made with spores from a pure 

 culture made from the canker on a Jajjan plum, in which the disease was readily 

 connnunicated. 



The leaf blight, canker, and powdery nuldew of (juinces are reported as causing 

 considerable damage, and a num])er of other diseases occurring less frequently than 

 usual. 



A peculiar form of raspberry anthracnose, due to Glceosporlum venetum, is described. 

 Ordinarily the anthracnose rarely attacks the red raspberries, but during the season 



