Miscellaneous. 437 



susceptible. Pale brownish spots are seen upon their upper surfaces, 

 while on their lower surfaces grey downy patches appear. These 

 patches are produced by outgrowths of the branched fungal filaments 

 from the breathing pores. On the ends of these branches bunches of 

 oval-shaped spores are borne. These spores carry the disease to other 

 plants. Later in the year winter spores are formed in the diseased leaf 

 tissue. These are set free by the decay of the leaves in the spring to 

 start a new infection. 



The next most important point of attack is the fruit. It is generally 

 attacked when only partly grown. It turns to a brownish color and be- 

 comes soft and shriveled, followed by a downy spore growth. Young 

 shoots are usually killed when affected. 



The same treatment is used for the downy mildew as for the black 

 rot. 



BLACK ROT OF THE GRAPE. 



Guignardia hidivcUi (Ell.) Viala ct Rav. 



The black rot is a common and injurious disease of the grape. It 

 attacks all parts of the vines except the roots. Upon the leaves it pro- 

 duces reddish brown spots. Within these spots are formed small black 

 bodies, with an opening, through which the small summer spores, which 

 are produced within, escape. The fruit which is attacked when it is half 

 grown begins to rot by turning brown ; finally it dries up into a wrinkled 

 black mummy. The small black summer spore containers are also found 

 here. 



Late in the year other small black bodies appear on the old grapes 

 and leaves hanging on the vine or fallen to the ground. These bodies 

 contain the winter spores, which are formed in small sacs. It is from 

 these that the infection starts anew in the spring. 



All the rubbish and old fruits about the vines should be destroyed. 

 Diseased parts should be trimmed and burned as soon as they appear. 

 Plants should be sprayed with Bordeaux before and after blossoming, 

 and at intervals of two weeks thereafter until the middle of July. From 

 then till the middle of August Soda Bordeaux or ammoniacal copper 

 carbonate may be used. 



LEAF SPOT OF TOMATO. 



Scptoria lycopcrsici Speg. 



Leaf spot is a very serious disease of the tomato. It attacks the 

 leaves, stems, and sometimes the green fruit. The leaves become covered 



