164 The Colorado Experiment Station 
yield and percentage of sugar in the beet by obtaining the yield and 
percentage of sugar in 127 cases, on fields aggregating about 2,50a 
acres from 16 sections or districts of the Arkansas Valley. Some 
of these fields were badly affected while others were not. The 
yield and percentage of sugar varied greatly, but there was very de¬ 
cidedly greater differences in-both the yield and percentage of sugar 
in the different districts than between the individual fields in the same 
distiict which had been attacked by the leaf-spot with varying de¬ 
grees of severity. The average percentage of sugar shown by the 
field samples from some of the fields which had been severely affected 
by leaf-spot showed from 16 to 17 percent of sugar. These per¬ 
centages of sugar could not in these cases be attributed to drying out 
of the beets in the ground. The record of 127 fields does not show 
with any decisiveness what the effect of the leaf-spot is. The beets 
grown on the College Experiment Farm showed the same character¬ 
istics in their composition as those from the Arkansas Valley and 
they had not suffered from the leaf-spot, so it is not at all satisfac¬ 
torily shown what the effects of the leaf-spot really are. The re¬ 
sults obtained do not show any constant or definite relation between 
the severity of the attack and the yield and percentage of sugar. 
The development of the beet at the time of the attack is probably 
an important factor and this cannot be given. 
The thesis presented in tiffs bulletin is that the causes mentioned 
as the ones to which the deterioration of the beet is due have not 
been shown to pioduce the effects assigned to them; on the contrary, 
it is conclusively shown that neither alkali nor seepage, except pos¬ 
sibly in land wholly unfit for cropping, do not of themselves produce 
beets either low in tonnage or percentage of sugar. Further, an¬ 
alytical results obtained with samples of the soil as well as the results 
obtained by experiments with fertilizers fail to show any lack of 
plant food, unless the analytical results be interpreted as indicating 
a lack of nitrogen, which interpretation is contradicted by the results 
of experiments with nitrogenous fertilizers. Further, that while the 
leaf-spot is very serious, we have been unable to detect any such rela¬ 
tion between the severity of the attack of this disease and either low- 
tonnage or low quality of the beet as to justify us in attributing the 
general deterioration which has taken place during the past eight or 
ten years to this cause. Further, that while climatic conditions, late- 
frosts in the spring, early ones in the fall, long continued hot 
weather, high winds, failure of water or severe and general hail 
storms are all factors in determining the tonnage and quality of a 
crop, the facts obtaining during the past ten years do not justify a 
serious consideration of “climatic conditions” as the cause of the 
deterioi ation, for it has continued very generally throughout a large 
disti ict for a number of years in which the “climatic conditions”* 
