METHODS OF CONTROL 199 



they pass all usefulness and as soon as they 

 have sufficiently dried. The expense ai^d 

 the labor of this operation should not in- 

 fluence the grower to neglect this. This is 

 especially true for the seedsman whose 

 success depends largely on clean lands in 

 order to produce clean seed which will 

 meet the market requirements. 



(b) Manure. Florists and growers 

 often dump potted plants on the manure 

 pile or on the compost. Such plants may 

 often be infected with some of the soil 

 troubles to which the sweet pea is sus- 

 ceptible. The use of such infected manure 

 or compost may mean the ruin of an entire 

 field. To avoid outdoor contamination of 

 our sweet pea soils, extreme care must be 

 taken that no contaminated manure or 

 compost find its way into the plantations, 

 (c) Crop Rotation. This is an essen- 

 tial and effective means of controlling soil 



