The leaves, however, continue to remain deep dark green, and do not dry up as 

 normal plants, brown after a transitional yellow stage. Usually smaller or larger 

 black-green or black-brown spots appear on the leaf veins, mostly in the neigh- 

 bourhood of the apex, this, after a weakening of the colour, with a light reddish 

 bronze tint. The leaf soon dries up into a deep dark brown or black-green colour, 

 without turning first yellow. Moreover, it sometimes happens that a leaf or part 

 of one after suddenly welting, turns quickly into a colour varying from a dark grey 

 green to a blackish colour. If there is very little phosphoric acid present, the 

 vegetation also is retarded and the leaves assume easily a lying form. These 

 manifestations were all clearly evident in the present experiment during 1913. 

 Although in the case of phosphoric acid starvation the beets may remain small 

 in size, they are healthy. The sugar content is in general only slightly lowered: 

 however in the case of a greater deficiency of phosphoric acid, should the 

 nitrogen be present, in relatively large surplus, then under certain conditions, the 

 sugar content may be further lowered. 



Table 19. 

 (Plot 5.) 



This plot received the same quantities of Nitrogen and Phosphoric Acid as Plot 1, 



but a much increased quantity of Potash. Under such manuring, the beets grew 



similar to those on Plot 1, but by the advanced growth about August and 



September, it was evident that the increased Potash had greatly hastened the 



24 — 



