A Fruit Survey or Mesa County 
13 
by Dr. Headden and later by Professor Sackett of this station, and 
these gentlemen have carried on extensive experiments to dis¬ 
cover the cause or origin of the niter. These experimentors have 
clearly proven that the presence and accumulation of the niter in 
the Grand Valley is of a bacterial origin. The accumulation 
of niter is much more rapid on lands under a clean culture sys¬ 
tem, and consequently the orchards were first to suffer from this 
trouble. In some cases the niter has accumulated to the extent 
that all vegetation has been killed and the land left entirely barren 
and unproductive. A considerable percentage of the older 
orchards were killed and the land left barren through niter ac¬ 
cumulations. 
The Horticultural Department, about three years ago, under¬ 
took to carry on some experiments with the view of eliminating 
or neutralizing the effect of the niter and making the land produce 
a normal crop. The results of these experiments show that the niter 
problem can be handled by the use of cover crops which will pro¬ 
tect the land during the summer and by the effect upon the soil of 
turning under the green materials grown. This method is effective 
and should be practiced by fruit growers whose orchards are not 
as yet suffering to any extent from niter trouble. Where the land 
has gone so bad as to become barren, the only method known by 
which it can be reclaimed is by washing the soil. The nitrates 
being soluble in water can easily be washed out by heavy 
flooding or heavy irrigation. This method was tried on a 
piece of land that was entirely barren and in two years the land 
was entirely reclaimed and produced normal crops. This washing 
or flooding of the land calls for drainage to carry off the surplus 
water. It also requires that the land should have at least a gentle 
slope to permit the water to run off freely. This method of re¬ 
claiming niter land is not applicable to land in growing orchards. 
The cover crop method is the only safe and rational way of over¬ 
coming niter accumulation, and it is a-rational method of orchard 
management that every intelligent fruit grower should follow. In 
other words, the niter problem should not occur if rational methods 
of orchard management are followed out. 
COST OF SPRAYING 
The mean of 34 estimates on the cost of spraying per 200 gal¬ 
lon tank is $2.05. For the cost per acre per season of arsenical 
sprays, 41 estimates gave an average of $20.00. This, divided by 
5.85 (the average number of sprays per season for apples for the 
Valley), gives $3.40, or the average cost per acre for one applica- 
