114 Diseases of Greenhouse Crops 



may be fumigated with carbon bisulphide. Under 

 no circumstances should infected plants be syringed. 

 When this is done the spores of the fungus are scat- 

 tered broadcast. Recently Burkholder * has suc- 

 ceeded in developing a resistant bean by crossing the 

 Well's Kindney Bean with the White Marrow va- 

 riety. 



Root Rot, see Rhizoctonia, p. 20. 



Root Knot, see Nematode, p. 28. 



Beet (Beta vulgaris'^^ 



Cultural Considerations. Beets are not grown 

 very extensively in the greenhouse. They are, how- 

 ever, raised on a small scale for greens or for the 

 roots. It is often used as a companion crop with 

 tomatoes. The Egyptian or any other early variety 

 is preferable. The cultural requirements of the beet 

 are the same as those of the lettuce, see p. 145. 

 However, beets will grow more rapidly under higher 

 temperatures than lettuce. 



Diseases of the Beet 



Indoor beets are subject to less diseases than those 

 grown out of doors. The following are the more 

 important ones: 



Crown Gall 



Caused by Fseudomonas tumefaciens Sm. and 

 Town. 



'Burkholder, W. H., Pbytopath. 8: 353-359, 1918. 



