138 INSECT PESTS 



they soon penetrate the tissue to commence their cycle 

 of life again. Lime is fatal to the Fingers and Toes 

 disease, and the ground should therefore be dressed with 

 ordinary slaked Ume, powdered and spread evenly. This 

 is better than the ground lime sold, as it is cheaper and 

 contains no impurities. (See Plate 32.) 



The Heart Rot of Mangolds and Swedes, and of Sugar 

 Beet, is not so common in this country as in France, 

 but cases have been known of a whole field with every 

 root badly infested. The fungus, Sphaerella tahifica, 

 germinates first on the stalks and upper part of the plant, 

 the leaves wilting, and finally penetrating the crown of 

 the root, where the work of destruction goes on out of 

 sight, leaving the interior an ugly black decayed mass. 

 On no account should diseased roots be left long about 

 or fed to animals, but burnt to ashes as soon as possible. 

 Red Beet is hardly ever attacked by this disease, and 

 may, therefore, be grown where this fungus has occurred. 

 We now pass to Beans and Peas. These crops, as 

 we might expect, have been specially adopted by parti- 

 cular species of fungi. (See Plate 32.) 



Bean Rust {Uromyces fabce) is familiar enough. It 

 occurs on both broad and runner beans, and takes the 

 form of a leaf spot as shown in the sketch, the fungus 

 itself being a collection of simple egg-shaped cells. Two 

 kinds of spore are shown, much enlarged, representing 

 two stages in the growth. Spraying does not injure this 

 fungus, and all bean haulm should be watched so that 

 diseased portions may be at once burned. The compost 

 heap is very valuable to the grower in these days, but 

 every care should be taken that it is not allowed to become 

 a fungal nursery. 



Scarlet Runners and French Beans suffer more severely 

 from Pod Canker, Colletotrichum lindemuthianum, than 

 they do from Rust. It makes its first appearance on 

 the pods in the form of dark patches, which indicate the 

 presence of the rooted spores. These soon cause the 



