44 
THE COLORADO EXPERIMENT STATION 
the application of insecticides in this bulletin. There are so many 
manufacturers of spraying machinery now that it would be impos¬ 
sible to show pumps and other appliances made by more than a few 
of them. At the close of this article is a list of some of the more 
prominent dealers in spraying machinery. One who contemplates 
purchasing spraying apparatus should write to a few of these firms 
for catalogues, and then select what seems to be the pump or other 
machine that is best suited to his needs. Advertisements of other 
dealers in spraying machinery may be found in papers and maga¬ 
zines devoted to agricultural and horticultural pursuits. 
APPLICATION OF DRY INSECTICIDES. 
The upper surface of the leaves of all low plants can be easily 
treated with a dry insecticide by dusting it through a cheesecloth, 
or other thin muslin bag held in the hand. There are also various 
dust sprayers of large and small sizes upon the market. 
By whatever means the dust is distributed it is best applied 
in the evening or early morning when foliage is slightly moistened 
with dew, or after a shower. 
APPLICATION OF WET INSECTICIDES. 
THE PUMPS. 
Pumps with metal valves should be obtained for the applica¬ 
tion of insecticides or fungicides in liquid form, as the materials 
used harden or decompose leather valves so that they last but a 
short time. If the pump is to be used with a tank or barrel it is 
also important to have some kind of attachment that will keep the 
liquid agitated so the materials in suspension will not settle. A 
common error is to purchase a pump of too small capacity, because 
it is cheaper. A smaller, cheaper pump usually means less accom¬ 
plished in a day with same help and a poorer job, with a greater 
expenditure of labor. And then, it is often important to complete 
the spraying in as short a time as possible after it is begun. To do 
this, a pump of large capacity with two or more leads of hose is 
necessary. The hose to which the nozzles are attached should be 
as light as possible and still have the requisite strength—a hose of 
good quality with heavy wall, but small caliber. Bucket pumps 
are sold by different dealers at prices ranging between about $2.00 
and $8.00 in price. They are suitable for use among garden vege¬ 
tables, shrubbery and all low plants, but should not be purchased 
for orchard work if one has more than a very few trees to treat. 
If one has light spraying to do and is without help, the com¬ 
pressed air sprayers are very convenient. Large compressed air 
sprayers that derive their power from gearing attached to the 
