The Fungus Pests of Garden Plants 



is not worth digging, or who bury diseased haulm and tubers in a 

 shallow trench, under the impression that it is a safe way of getting 

 rid of worthless vegetation, are simply storing Phytophthora for 

 another attack in the event of Potatoes being planted in the same 

 land again. If buried at all, it must be at a considerable depth, but 

 the effectual method is to destroy all Potato refuse by fire. 



Lettuce Disease. This fungus is named Perotwspora gangli- 

 oniformis, and is sometimes of the most destructive character. It 

 covers Lettuce leaves with a fine white bloom, known as Lettuce 

 Mildew, which decomposes the leaves, and makes them adhere 

 together in one putrescent mass. It should be looked for in its 

 earliest stages, and be hand-picked and burned. Old Lettuce stumps 

 should likewise be pulled and burned, otherwise they may harbour 

 the disease. 



Onion Disease. This is known as Onion Mildew, and is 

 caused by the fungus Peronospora Schleideniana, which is occasion- 

 ally disastrous in its effects. In some districts the mildew is almost 

 unknown ; in others it is common. It occurs at uncertain intervals of 

 time with extraordinary virulence, and then utterly destroys the crops. 

 Autumn sowing is considered a good preventive by many growers, 

 as the disease is frequently fatal to spring seedlings. Wherever 

 practicable mildewed Onions should be removed and burned. 



Parsnip Disease. The Mildew of Parsnips is due to the fungus 

 Peronospora nivea, which causes the roots to become putrescent 

 in the style of bad Potatoes. Here again it is advisable to burn 

 infested plants, in order to destroy the resting-spores of the fungus. 



There is also a Peronospora peculiar to the Pea tribe, another on 

 Spinach, one on Clover, one of the most destructive character on 

 'Roses, and others on the many diverse plants of our fields and 

 gardens. The resting-spores are known in several instances. 



Pea Disease. Although garden Peas often suffer badly from 

 the attacks of Peronospora vicice, which is the cause of Pea Mould, 

 yet the most deadly foe to Peas, especially late Peas, is a fungus of a 

 totally different character. To such an extent does the Pea Blight 

 sometimes devastate the later Peas round London in dry summers, 

 that the whole crop is in some gardens completely annihilated. 



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