12 



THE CURLY-TOP OF BEETS. 



SYMPTOMS IN SEED BEETS. 



When beets are grown a second season for the production of seed 

 the symptoms of the plants affected with curly-top are similar to 

 those already described, but a much larger proportion of the re- 

 tracted type prevails. In addition, many seed beets are quite unable 

 to develop seed stems; instead, the leaves gradually wither and the 

 whole plant dies. In other cases feeble stems are produced which 



Fig. 3. — Curly-top sugar beet, dorsal surface of leaves; the same plant shown in figure 2. 



may or may not reach the flowering stage and then dry up and die; 

 still others possess enough vitality, though badly dwarfed and stunted, 

 to bear and mature seed (PI. VI, fig. 1). 



Quite frequently the roots of seed beets affected with curly-top 

 are found to have rotted areas of varying extent, sometimes involving 



° While the term " mother beet " is probably the more familiar one, " seed 

 beet " is considered better, inasmuch as beet flowers contain both male and 

 female organs. The term " mother beet " implies that the flowers of the seed- 

 bearing plant contain only the female organs. 



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