orchard spraying experiments in i912. 67 



Discussion of Results. 



As has already been mentioned the original plan of the ex- 

 periment called for an application of the various sprays when 

 the flower buds began to show pink, or before they opened. 

 The failure to do this greatly lessene'd the value of the data 

 which it was planned to obtain. Fortunately, however, this 

 omitted spray was applied to the adjoining orchard from which 

 plot G was taken. As a result certain other data were obtained 

 which are doubtless of more practical value than that originally 

 desired. 



Efficiency of the first spray application. Perhaps the most 

 striking thing about the results secured is with regards the value 

 of the spray applied before the blossoms opened as compared 

 with the two following applications. This is shown by the 

 figures obtained on plots C and G. The treatment on these two 

 plots being exactly alike except that on C the first spraying was 

 om'tted. In one case only about 50 per cent of perfect apples 

 were obtained and nearly all of the remainder of the fruit was 

 scabbed. In the other nearly 90 per cent of the fruit was sound 

 and perfect and less than 1.5 per cent was scabby. It is true 

 that on the last plot nearly 10 per cent were classed as russeted 

 but this figure is somewhat misleading as the russeting was, as 

 a rule, very slight. Very few of these so-called russeted apples 

 would have to be sold for less than a No. 2 grade. 



The general conclusion was that, under the existing weather 

 conditions of the past season, where the first spraying was 

 omitted the profits derived from the two following sprayings 

 paid little more than the cost of application. This statement 

 should not be taken as implying that these are not important or 

 advising that they should be omitted, but as pointing out the 

 great importance of the first spraying, applied at the proper 

 time. The more complete knowledge of the Hfe history of the 

 scab fungus which has been gained in recent years coincides 

 with these experimental results. 



The fungus passes the winter on fallen leaves under the trees. 

 In early spring on these leaves of the season before it matures 

 within a capsule an entirely dififerent type of spore from that 

 which leads to the propagation and spread of the fungus during 

 the following summer. These sac spores are thrown out in the 



