132 VEGETABLE FORCING 
portant fungicide for the treatment of vegetables grown 
under glass. The chief objection to its use is the dis- 
coloration of the fruits or products, and this is a serious 
objection if the mixture is applied to the crops a short 
time before they are to be marketed. The strength of the 
proportions of the mixture may vary from two pounds of 
copper sulphate and two pounds of stone lime to 50 gal- 
lons of water, to five pounds of copper sulphate and five 
pounds of stone lime to 50 gallons of water. Ordinarily, 
plants like the cucumber and tomato are not injured if 
the 5-5-50 formula is employed. 
Various directions are given for making bordeaux mix- 
ture, but a simple plan is to dissolve the copper sulphate 
in a few gallons of hot water in a wooden pail. Slowly 
slake the lime in another vessel and add enough water 
to make a thick milk solution. The dissolved copper sul- 
phate is then poured into the barrel or tank containing 
about 40 gallons of water, the lime milk added and the 
solution stirred. Additional water may be used if nec- 
essary to make the total volume 50 gallons. Separate stock 
solutions of copper sulphate and of lime milk may be 
kept on hand, but the prepared mixture deteriorates when 
left standing. It is important that unslaked stone lime 
rather than air-slaked lime be employed. Air-slaking 
may be prevented by keeping the stone lime in tightly 
covered vessels. The Ohio Station reports that bordeaux 
mixture is most effective when the atmosphere of the 
house is so highly humid that the leaf surfaces are moist. 
Ammoniacal copper carbonate.—As previously indi- 
cated, bordeaux mixture leaves a deposit on the plants 
and fruits which is objectionable if the products are soon 
to be marketed. For this reason, some growers prefer to 
use ammoniacal copper carbonate—which leaves only a 
slight deposit—previous to harvesting and marketing 
certain crops, though this fungicide is not so effective as 
bordeaux mixture. The mixture contains the following 
constituents: 
