The Fungus Pests of Garden Plants 



X-IOO- 

 FUNGUS OF PEA MILDEW 



Erysiphe Martii 



The name of the fungus of the Pea Blight or Mildew is Erysiphe 

 Martii. Its attack is often made suddenly ; the leaves then lose 

 their natural green colour, and become yellowish and densely coated 

 with a fine white bloom ; this bloom becomes at length dusted over 

 with innumerable minute black bodies, which look, under a lens, like 

 tiny spiders'-eggs in the web. These little black bodies are filled 

 with extremely small transparent vessels, and each vessel contains 

 from four to eight spores or 

 seeds. Our illustration shows 

 this Erysiphe enlarged one 

 hundred diameters, with two 

 of the vessels containing the 

 spores removed from the 

 globular spots and further 

 enlarged. The only safe way 

 of dealing with infested Pea 

 plants is to burn them. Many 

 other species of fungi belong- 

 ing to the same genus attack fruit trees, vegetables, and garden 

 flowers. It is, however, unnecessary to illustrate them, as they more 

 or less resemble the fungus of Pea Blight. They all arise from an 

 O'idium condition, similar to the Oidium or Mildew of the Vine, and 

 it is in this condition alone, as in the case of the Vine, that they can 

 be reached by any fungicide. 



Tomato Diseases. Of late years Tomatoes have been exten- 

 sively destroyed by several virulent forms of disease. The first to 

 attract attention was a disease of the leaves in which these organs 

 became entirely enveloped in a dense pearly white or pinkish mass 

 of powder or mould. In severe cases of this disease the leaves 

 are twisted, thickened, and distorted ; they next quickly rot and fall 

 off, so that the Tomato plants are ruined. When this Mildew for 

 such it is is examined under the microscope and magnified three 

 hundred diameters, there is seen, as in the accompanying illustration, 

 a vast mass of thickly compacted, transparent fungus threads, with an 

 infinite number of pale rose-coloured spores : the spores are often 

 jointed, and so break up into two, three, or four pieces, and every 

 piece germinates as shown at A, B, C, D, thus reproducing the 

 fungus. The spore production is so profuse that in bad cases, 

 when the leaves are touched, the spores may be seen dispersed 

 in the air like a vapour or mist. The spores germinate not only 



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