CHAPTER y 



FIELD DISEASES OF SWEET PEAS 



As previously noticed, the diseases which 

 affect sweet peas under glass may also be 

 present out-of-doors. In fact the fungi 

 such as Thielavia, Rhizoctonia, Fusarium, 

 Sclerotinia, etc., are all known to induce, 

 very commonly, diseases on plants in the 

 field. Indeed their appearance in the 

 greenhouse indicates their presence some- 

 where in the field or in the manure pile, 

 whence they are usually introduced into 

 the soil. The spread of these fungous 

 pests is favored by unnatural conditions 

 which may occur in the field as well as in 

 the greenhouse. Continuous foggy and 

 damp hot weather, together with infected 



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