22 
The Colorado Experiment Station 
Fig. 7 .—a 13-nozzle beet spraying machine. The type that was used in 
the grasshopper campaign, 1916, San Luis Valley. (Original). 
Iii fields where the Paris green bran mash had been applied 
and reported ineffective, an estimate as to the efficiency of the 
poison was made, and it was found that the dead hoppers aver¬ 
aged 37 to the square foot. On computation, it was found that, at 
this rate, there would be about 9 bushels of dead hoppers per 
acre. 
The general prevailing opinion at that time was that the hop¬ 
per dozer was more effective than the poison. This was undoubt¬ 
edly due to the fact that the fruits of their labor were discern¬ 
ible and not scattered, as was the case with the poison. However, 
estimates showed that the spray and the poison bait were at least 
four times as effective- as the hopper dozer. 
Demonstrations relative to mixing and applying sprays and 
poisons in various communities were held, and always with a good 
attendance of interested farmers. Several trips were made to 
fields of peas, part of which had been plowed in the early spring, 
and the remainder left uncultivated, the peas being simply drilled 
into the old stubble as is the common custom in that vicinity. 
The plowed areas demonstrated quite clearly the effect of 
early spring or fall cultivation for the destruction of eggs, as 
there were very few, or in most cases, no grasshoppers in the cul¬ 
tivated plots, while where the peas were simply drilled in the 
stubble, there appeared about as many hoppers as in the unculti¬ 
vated fields of that vicinity. 
