168 Repoet of the Botanist of the 



and thriftiest at the time of the injury were the ones most severely 

 affected; and, further, that during two months of second growth 

 the surviving plants increased the size of their roots but little. 



That the discoloration of the root is a physiological effect (the 

 result of the death of the foliage) rather than the work of any 

 parasitic organism is shown by the results of the following inocula- 

 tion experiment : After the dirt around five healthy sugar beets 

 had been removed there was cut from each a pyramidal cavity 

 one-fourth inch square at the surface and one-half inch deep. 

 These cavities were then filled with similarly shaped plugs of 

 the discolored beet root, the whole covered with grafting wax 

 and the dirt replaced. Five check beets were treated in the same 

 manner except that the cavities were filled with plugs of healthy 

 beet. This was done August 30. On October 18 the beets were 

 pulled and cut open. The inoculated beets showed no discolora- 

 tion of tissue except a slight blackening around the wounds, 

 which was no greater than in the check roots. 



Some farmers thought that the beet disease was much worse 

 on land where cabbages were affected by black rot in the season 

 of 1898, but our own observations show that there is not good 

 foundation for such belief. It can be stated positively that there 

 is no connection between the leaf scorch of beets and the black 

 rot of cabbage. 



The amount of damage done to the beets was considerable. 

 Although the majority of the plants recovered, the roots were 

 smaller than they otherwise would have been and their sugar con- 

 tent was lower. Analyses made by Mr. J. A. LeClerc, Assistant 

 Chemist, gave the following results: (1) "Roots of plants killed 

 outright analyzed 5.9 per ct. of sugar fin the juice) with a 

 coefficient of purity of 61.6; (2) Roots of plants which had 

 made a second growth after having all their foliage killed 

 analyzed 10.7 per ct. of sugar, coefficient of purity, 73.6; (3) 

 Roots of uninjured plants growing within a few feet of the di- 

 seased plants analyzed 15.2 per ct. of sugar, coefficient of purity, 

 80.3. 



