560 DISEASES OF CULTIVATED PLANTS 



flowering plants, Chrysanthemum, Begonia, Calceolaria, Glox- 

 inia, Coleus, Saint Paulia, etc., forming more or less extended 

 brown patches. 



Much injury, attributed to Thrips and other agents, is often 

 caused by this eelworm in greenhouses, etc. 



Treating the soil with carbon disulphide destroys the 

 eelvvorms, but not their eggs. Dusting the plants, when 

 moist, with a mixture of tobacco powder and flowers of 

 sulphur, prevents the eelworms from ascending and entering 

 the leaves. 



Strawberry ' Cauliflower ' disease. Strawberry plants 

 often suffer from a serious disease caused by an eel- 

 worm (Aphelenchus fragariae, Ritzema Bos). The disease 

 takes the form of a more or less consolidated or fasciated 

 mass of stems, leaves, and flowers, all more or less grown 

 together and forming a fleshy malformation, somewhat resem- 

 bling a cauliflower in general appearance. Those flowers 

 that remain free from the general mass assume monstrous 

 forms. The eelworms are met with in abundance in the buds 

 and are comparatively small. Miss Ormerod states that 

 sulphate of potash at the rate of one cwt. per acre has 

 had a good effect in stopping the disease and bringing a good 

 crop; also at the rate of about one half cwt. per acre it has 

 done well. 



As a manurial application, a mixture of about two parts of 

 sulphate of potash, three parts sulphate of ammonia, and 

 four parts of phosphates brought remarkably healthy crops, 

 with few exceptions. 



Ormerod, E. A., Handbook of Insects Injurious to Orchard 

 a 'id Bush Fruits, p. 251 (1898). 



Ritzema Dos, /,//. IjLur.enkr., 1, p. 1. 



ApheUnchus ortnerodis (Ritzema bos) is a second species, 

 also first observed attai king strawberry plants in England. 



Ritzema bos. Zeit. P/lanzenkr., 1, p. 11. 



