12 
EXPERIMENTS IN THE TREATMENT OF PLANT DISEASES. 
By B. T. Galloway. 
(Plate IV.) 
Part III. 
In addition to the field work conducted in 1890 by the Division of 
Vegetable Pathology and set forth in Parts I and II of this article, a 
series of experiments were made under our direction by field agents 
located in various parts of the Union. The reports of these agents have 
all been received, and while it is our usual custom to publish them in 
the form of a special bulletin several reasons make it more desirable to 
give them in a condensed form here. 
TREATMENT OF GRAPE DISEASES. 
-These experiments were carried on at Greenville, South Carolina; 
Vineland, New Jersey; and Neosho, Missouri. The work in the main 
was planned to throw additional light on the treatment of black rot, 
which is everywhere recognized as being the most destructive of all 
grape maladies. The questions we were desirous of obtaining more 
information upon may be briefly summarized as follows: 
I. A comparison of the fungicides given below as regards cost, effi¬ 
ciency, and effects on the healthy foliage and fruit. 
(a) Bordeaux mixture prepared in accordance with the usual formula, 
i. e ., copper sulphate 6 pounds, lime 4 pounds, and water 22 gallons. 
( b ) Bordeaux mixture prepared the same as a , then allowed to settle. 
After this has taken place drawing off the clear liquid and drying the 
sediment the latter being simply mixed with water when used. The 
object in using this preparation was to determine if possible whether 
the Bordeaux mixture prepared in advance was as effective as that 
made in the usual way. The question has considerable practical im¬ 
portance as there is an increasing demand for a mixture ready for use. 
This demand is mostly from small growers who do not care to go to the 
trouble of buying the copper and lime and making their own mixture. 
( c ) Modified eau celeste containing copper sulphate 4 pounds, aqua 
ammonia 3 pints, carbonate of soda 5 pounds. 
( d ) Copper carbonate in suspension, 3 ounces to 22 gallons. This 
being a much cheaper preparation than the ammoniacal copper carbon¬ 
ate solution, it was thought best to give it a thorough trial. 
(e) Simple milk of lime made by dissolving 3 pounds of lime in 25 
gallons of water. 
(/) Solution of copper acetate, 2 pounds to 22 gallons. 
{(j) Mixture No. 5 consisting of equal parts of ammoniated copper 
sulphate and ammonia carbonate. Used at the rate of 1 pound to 
