PURDUE UNIVERSITY
Agricultural Experiment Station
Circular No. 34
LaFayette, Ind., March, 1912
ORCHARD SPRAY CALENDAR
M. W. Richards Department of Horticulture
The practice of spraying has developed so rapidly in recent years that the grower has had hard work to keep pace with it. New remedies have been discovered and old ones put to new uses until many fruit growers are confused in regard to the materials to use in the orchard and the time to apply them.
This circular has been prepared to meet the needs of such orchard owners. It presents a complete spraying schedule for orchard fruits with recommended formulae for preparing the materials and the approximate time of application for those which are most important and most generally used.
REMEDIES
Bordeaux Mixture
Formula— 4 pounds copper sulphate (blue stone)
6 pounds lime (unslaked stone lime or hydrated lime)
50 gallons water
Bordeaux mixture has long been the standard fungicide used in orchard spraying. It is made by suspending four pounds of copper sulphate in a gunny sack in about 15 gallons of water. The copper sulphate dissolves and a clear blue solution is formed. Six pounds of lime are slaked and diluted to about 15 gallons. The dilute solution of copper sulphate and the milk of lime are then poured through a strainer simultaneously into the spray barrel. The resultant mixture is diluted to 50 gallons and is known as Bordeaux. This is a very finely divided solid and is in suspension in the liquid. It must, therefore, be kept thoroughly agitated during application. In making large quantities of Bordeaux it is advisable to mix the copper sulphate and lime in stock solutions. This is done by weighing out a definite amount of each substance and then diluting them to a known volume as for example, 100 pounds of copper sulphate dissolved and made up to 50 gallons of water, and 100 pounds of