3e--Dry Wettable Flotation Sulfur. This sulfur dust, 
manufactured by the koppers products company, is similar to (2) above, 
but is produced in the manufacture of illuminating gas and is mado up 
of extromely fine sulfur particles. 
4.=--Kolodust. This is a sulfur dust manufactured by the Niagara 
sprayer and chomical company. This fungicide is similar to Koloform but is 
applicd as a dust. 
5.=--Flotation Sulfur Dust. This is a sulfur dust manufactured 
by the Koppers products company. It is composed of extremely fine particles 
ond is used as a dust. 
Applications of Bordeaux and wettable sulfurs have been made with 
sprayers owned by the nurserymen on whose grounds the trees have been located. 
The apparatus has varied from a 50 gallon hand operated outfit to a 100 gallon 
power machinc. In different plots the quality of application has necessarily 
varied somewhat, though every cffort has been made to secure the best possible 
spray coverage. Applications of sulfur dusts were made with a hand duster 
of standard make capable of throwing dust in a good cloud to a height of 
10-12 feet. In dusting, choice of the time of day was made so es to take 
advantage of dew as a dust holdor. 
First applications have been made yearly in May or carly Jume, and 
these have been followed at approximately 3 woek intervals by other 
applications, the last being made.in the last half of August. The test plots 
have, therofore, received treatment 4 to 6 times during cach growing scasone 
Emphasis has been laid on the summer treatment, since the so-called "wilt" 
goncrally begins to appear in July. Dormant applications have not been 
tested, since the possible effectiveness of fungicides was unknown. 
Results 
During and at the end of cach scason observations on the 
effectiveness of the various treatments have been made with care. These 
observations have related primarily, of course, to the uscfulness of cach 
fungicide in kceping down the general run of clm diseases included in the 
term “olm wilt," as used by nurserymen,. But other questions have been kept 
in mind also, such as whether fungicides affect the prevalence of leaf 
discascs and whether their use is generally beneficial or deleterious to 
trees. These points are reported on below, 
1.--Control of “wilt" diseases. It was realized, when these tosts 
were begun, that curing infections already present would be impossible, unless 
pruning should prove effective. The measure of the usefulness of cach 
treatment would lie in its ability to provent the occurrence of new infcctions. 
Presumably, the relative values of the different fungicides would be determined 
also by their relative degrees of success. Whether complete cure and 
prevention could be attained would be determined from combined fungicide and 
pruning treatmonts. Table 1 on the following page shows in bricf summary the 
results now at hand. 
salt 
