COKNELtL UNIVERSITY EXPERIMENT STATION BULLETINS. 308 



trying to spray through these branches, or past them, in order to reach 

 more important parts of the tree. Again, this extra work requires time. 

 During the spring of the year there is generally plenty of work to be done, 

 and extra help is expensive. It is no small task to spray an orchard, as 

 those who have tried it well know, and everything that will make the work 

 easier is worthy of attention. 



PART I.— EXPERIMENTS OF THE SEASON. 



iUntil recently, insecticides and fungicides have been applied separately. 

 The following experiments were made to determine the value and practi- 

 cability of spraying apple orchards with a combination of insecticides and 

 fungicides. From the good results which have commonly followed the use 

 of Paris green, it was thought possible that it may have some value as a 

 fungicide when used alone. Applications were made to test this point. 



The combinations applied were Paris green and the Bordeaux mixture, 

 andfLondon purple and the Bordeaux mixture. Paris green was also used 

 alone. The arsenites were used at the rate of two and one half ounces to 

 40 gallons of liquid, which is the equivalent of one pound to about 250 

 gallons. The Bordeaux mixture was made according to the formula: 



Sulphate of copper (crystals) 6 pounds. 



Lime (unslaked) 4 pounds. 



Water 40 gallons. 



The sulphate of copper dissolves very slowly in cold water. It is better 

 to buy it in the form of a powder, or to use boiling water, which dissolves 

 it more quickly. Four or live gallons of hot water should readily dissolve 

 enough of the copper sulphate to make 40 gallons of the mixture. It is 

 better to use quick lime, but that which has been air-slaked will also 

 answer the purpose if about one fourth more is used. (See part 11.) 



The arsenites were added to the mixture just before the applications 

 were made to the trees. The mixtures were carried in the orchard in a 

 barrel holding 40 gallons, and lying horizontally upon a wagon. The pump 

 used was No. 549 of the Deming company, Salem, Ohio. It was secured to 

 the top of the barrel as shown in the cover illustration. A hose, which 

 discharges into the barrel for the purpose of keeping the mixture stirred, 

 may be attached to the pump, but this was not used. The liquids were 

 stirred by means of a stick which was inserted inro the barrel through the 

 hole used in filling. A thorough stirring was given before spraying each 

 tree. It was found that two persons working together could do the work 

 most satisfactorily; one drove and directed the spray while the other 

 pumped. The nozzle used was one invented by the owner of the orchard. 

 It throws a fine spray with much force, which makes it well adapted for 

 orchard work. 



The amount of liquid applied to each tree averaged about four and one- 

 half gallons per application. The trees are about twenty years old. They 

 are thrifty and in excellent condition. The retail price of the sulphate 

 of copper is about 8 cents per pound, and Paris green is sold for about 35 

 cents. Adding the cost of the lime at 30 cents per bushel, this makes the 

 actual outlay per tree for material about 5 cents for each application of 

 the combination of Bordeaux mixture and Paris green. If London purple 

 were used it would reduce the cost a little, for this poison should sell for 

 about 20 cents per pound retail. If Paris green is used alone the cost of 



