32 



MASS. EXPERIMENT STATION BULLETIN 214. 



Plot 9. — A 4-50 dry lime-sulfur for the pre-pink, pink and following sprays. 

 Plot 10. — A 3-50 dry lime-sulfur plus arsenate and nicotine. 

 Plot 11. — A 3-50 dry lime-sulfur plus nicotine sprayed on the trees, allowed to 

 dry, and then the arsenate applied. 



Time and Manner of Spraij Applications. 

 Table II. — Ti7ne of Application of Sprays for 1921 and 1922. 



Application. 



1921. 



1922. 



Delayed-dormant 



Pre-pink 



Pink . 



Calyx . 



Fourth summer . 



Fifth summer 



April 4- 6 



April 25-27 

 May 10-12 

 June 6- 8 



April 13-19 

 April 28-May 3 

 May 3- 8 

 May 16-20 

 June 9-22 

 June 25-31 



As previously explained, two additional applications, the pre-pink and 

 fifth summer, were made on some of the plots in 1922. Power sprayers 

 which maintained approximately 200 pounds pressure were used, with 

 spray rods equipped with the regular 45° Friend angle nozzles. By 

 holding the rod close to the ground and in such a position as to shoot the 

 sprays upward, the under surface of the lowest leaves was thoroughly 

 covered. As these are the first leaves attacked by the scab fungus, it is 

 exceedingly important that they be well covered at the pre-pink and pink 

 applications. 



Discussion of Results of Spraying. 



Throughout most of the season weather conditions were exceedingly 

 favorable for scab infection. 



It will be noted in Tables IV, V and VI (pages 40 and 41) that all of 

 the sprays gave exceptionally good control. In fact, many of the sprayed 

 plots produced 100 per cent marketable fruit, whereas some of the checks 

 produced fruit 100 per cent scabbed. There was not a single scab-free 

 apple on the 16 check trees in the Sabine orchard, and 95 per cent were 

 so badly scabbed that they were unmarketable. In the Knights orchard 

 the situation was nearly as bad, 96 per cent of the fruit being scabbed 

 and 69 per cent unmarketable. In the Frost orchard infection was not 

 quite as severe, only 41 per cent of the fruit being scabbed. 



Only small and probably insignificant differences were found in the 

 results obtained from the different fungicides in so far as control of the 

 scab fungus is concerned. 



Importance of the First Spray Applications. 

 The dissemination of scab spores is most rapid about the time of the 

 pink application. Tliis is, therefore, the most important spray and should 

 be so timed that it will be on the foliage, blossoms and pedicels of the 



